132 results on '"Singhal RS"'
Search Results
2. Studies on inhibition of α-glucosidase using debittered formulation of Bacopa monnieri juice: Enzyme inhibition kinetics, interaction strategy, and molecular docking approach.
- Author
-
Jana SB and Singhal RS
- Abstract
Bacopa monnieri juice (BMJ) is traditionally used, reported, and scientifically validated for memory enhancement. However, its efficacy against diabetes is less explored. The extreme bitterness of BMJ restricts its commercial applications. This study investigates the reduction of bitterness of BMJ followed by evaluation for its α-glucosidase inhibitory activity. Initially, debittering of 30 % (v/v) BMJ using ZnSO
4 (15 mM) was optimized by time-intensity analysis and molecular docking of ZnSO4 as well as bacoside A3, the main active compound in BMJ, with TAS2R14 taste receptor. The study indicated 5 hydrogen bonds to be involved in binding with bacoside A3 with binding energy of -11.82 Kcal/mol, while hydrogen bond, salt bridges and metal complexes were involved in binding of ZnSO4 with binding energy of -6.65 Kcal/mol. Subsequently, BMJ, ZnSO4 and BMJ + ZnSO4 (debittered juice) were also found to be potent inhibitors of α-glucosidase in dose-dependent manner. These inhibitors showed parabolic mixed inhibition of α-glucosidase, altered the secondary structure, and quenching of fluorescence. In silico studies revealed hydrogen bonding and hydrophobic interactions between inhibitors and α-glucosidase with lowest binding energy of -15.53 and -7.54 Kcal/mol being recorded for bacoside A3 and ZnSO4 , respectively. Molecular docking of other bioactive compounds in BMJ such as apigenin, luteolin, quercetin and bacopasaponin C also showed lower binding energy than the standard drug, acarbose (-5.84). This study inferred the binding of bacoside A3 at the active site of α-glucosidase and of ZnSO4 with other sites on the protein. The study proposes a debittered BMJ formulation to control hyperglycemia., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
3. Immobilization of l-asparaginase on genipin cross-linked chitosan beads shows better acrylamide diminution in cassava chips: Process optimization and characterization.
- Author
-
Danait-Nabar S and Singhal RS
- Subjects
- Food Handling methods, Asparaginase chemistry, Chitosan chemistry, Iridoids chemistry, Acrylamide chemistry, Manihot chemistry, Cross-Linking Reagents chemistry, Enzymes, Immobilized chemistry
- Abstract
Glutaraldehyde is the conventionally used cross-linker for the activation and cross-linking of support matrices used in enzyme immobilization. However, the toxic nature of glutaraldehyde makes it unsafe for food applications, propelling the need for nontoxic cross-linkers. Genipin reacts with the primary and secondary amines generating a dark-blue colored pigment and is an attractive alternative to glutaraldehyde as a cross-linker for enzyme immobilization. Apart from its excellent cross-linking properties, genipin possesses added advantages over glutaraldehyde such as proven health benefits, biocompatibility, and biodegradability. The present study explores the application of chitosan beads cross-linked with the natural and nontoxic agent, genipin, for immobilizing l-asparaginase, aimed at its subsequent use in mitigating acrylamide formation in food products. The immobilized l-asparaginase exhibited improved functionalities such as stability, reusability, and reduction in acrylamide formation in deep-fried cassava chips. One of the limitations observed during application in the food process was the mechanical fragility of the chitosan beads during speedy stirring. This can be overcome by increasing the concentration and time of contact of the coagulant bath during the formation of chitosan beads. The drying of the enzyme-bound chitosan beads will also lead to shrinkage and prevent breakage during stirring. This study conclusively demonstrated the applicability of immobilizing l-asparaginase on genipin cross-linked chitosan beads in food-related processes., (© 2024 Institute of Food Technologists.)
- Published
- 2024
- Full Text
- View/download PDF
4. Copper oxide nanoparticles exhibit variable response against enzymatic toxicity biomarkers of Moina macrocopa.
- Author
-
Borase HP, Singhal RS, and Patil SV
- Subjects
- Animals, Metal Nanoparticles toxicity, Water Pollutants, Chemical toxicity, Glutathione Transferase metabolism, Nanoparticles toxicity, Cladocera, Biomarkers metabolism, Copper toxicity
- Abstract
Growing toxicity of nanomaterials to aquatic organisms is a major area of concern as it is destroying the carefully evolved aquatic ecosystem and food web. Copper oxide nanoparticles (CuONPs) are among the top industrially manufactured nanomaterials having multifaceted applications in medicine, agriculture, energy, water technology, and other areas. However, reports on detailed scientific understanding behind toxic effects of CuONPs on aquatic organisms are scant. The present work reports on the interaction of CuONPs of 10 ± 05 nm with an ecologically significant aquatic species, Moina macrocopa, at morphological and enzymatic levels. CuONPs were found to be severely toxic just within 48 h of exposure as seen from the lethal value (48 h LC
50 ) of 0.137 ± 0.002 ppm. Profiling of enzymatic toxicity biomarkers indicated variable response of CuONPs on selected enzymes of M. macrocopa at two sub-lethal concentrations (0.013 to 0.039 ppm). While the activities of acetyl cholinesterase and digestive enzymes (trypsin, amylase) were found to be significantly (p < 0.001) lowered after exposure to CuONPs, the β-galactosidase activity was completely inhibited. Among the antioxidant enzymes that were assayed, superoxide dismutase and glutathione-S-transferase activity was found to increase (p > 0.001), while that of catalase decreased (p > 0.001, < 0.05) with increase in exposure to CuONPs. An upsurge of several folds was seen in the activity of alkaline phosphatase after exposure to CuONPs as compared to the control group. CuONPs accumulated in the gut region of M. macrocopa which provided an ideal environment for CuONP to interact and alter the enzymes in M. macrocopa. This report highlights the use of enzymes as sensitive biomarker to detect toxicity of trace amount of CuONPs in a very sensitive non-target crustacean species found in water bodies., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2024
- Full Text
- View/download PDF
5. Composite hydrogels fabricated from konjac glucomannan and gellan gum: Rheological characterization and their potential application in sustainable agriculture.
- Author
-
Basak S and Singhal RS
- Abstract
In this study, konjac glucomannan (KG) was incorporated in high acyl gellan (HAG) and low acyl gellan (LAG) hydrogels in different ratios. The addition of KG increased pseudoplasticity and thermal hysteresis values of the hydrogels. Improvement in elasticity and water holding capacity (WHC) was observed in KG-LAG hydrogels. The highest WHC (98.5 %) was observed for 1K1H (KG:HAG = 1:1) and 3K7L (KG:LAG = 3:7) hydrogels. The crystallinity of the composite hydrogels was lower than hydrogels prepared from individual biopolymers. The hydrogels exhibited a rough surface with minute pores in the cross-section, due to the aggregation of glucomannan on the gellan network in the composite hydrogels. While HAG and 1K1H hydrogels exhibited greater swelling at low pH (3.0), LAG and 3K7L exhibited greater swelling at high pH (11.0). At pH 7.0, the hydrogels exhibited swelling indices >300 %. Incorporation of 1K1H hydrogel at 10 % (w/w) in sandy loamy soil under semi-arid conditions increased the germination of fenugreek microgreens from 60 % to 80 % on the 15th day. Furthermore, the moisture evaporation rate of the soil reduced from 35 % to <15 %, positively impacting the physicochemical properties of the microgreens. The composite hydrogels were successful in achieving a controlled release of phosphate fertilizer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
6. Correction to: Mixed Culture Cultivation in Microbial Bioprocesses.
- Author
-
Khedkar M, Bedade D, Singhal RS, and Bankar SB
- Published
- 2024
- Full Text
- View/download PDF
7. In silico guided pre-treatment of sugarcane juice with natural inhibitors of polyphenol oxidase (PPO) is a new and effective strategy for development of spray-dried formulation.
- Author
-
Kanagaraj JC, Jana SB, Marathe SJ, and Singhal RS
- Subjects
- Catechol Oxidase chemistry, Molecular Docking Simulation, Ascorbic Acid, Sugars, Citric Acid, Saccharum chemistry
- Abstract
Sugarcane juice is a popular beverage and is also processed to produce sugar. The polyphenol oxidase (PPO) in sugarcane juice causes enzymatic browning and makes the process of sugar production complex and cumbersome. Storage of sugarcane juice is also hampered by the high sugar content and rapid microbial fermentation. The present research assessed the potential of lemon juice (LJ) and ginger extract (GE) as natural inhibitors of PPO. Enzyme kinetics and the mechanism of inhibition of LJ and GE were studied. Primary investigation was carried out using molecular docking approach to assess the inhibitory potential of LJ and GE and to determine the nature of interaction between the enzyme and inhibitors. Extracts were used as inhibitors and studies revealed that both reduced the PPO activity. Subsequently, pure bioactive inhibitors such as ascorbic acid, citric acid, and 6-shogaol present in these natural extracts were used to study the mode of inhibition of PPO. Citric acid decreased PPO activity by lowering pH, while ascorbic acid was found to be a competitive inhibitor of PPO with a K
i of 75.69 µM. The proportion of LJ and GE required in sugarcane juice was optimized on the basis of browning index and sensory acceptance. Further, the sugarcane cane juice after inhibition of PPO under optimized conditions was spray dried and evaluated for reconstitution properties. The product formulated in the present study is a new and effective approach to address quality-compromising issues associated with long-term storage of cane juice., (© 2024 Institute of Food Technologists.)- Published
- 2024
- Full Text
- View/download PDF
8. Mutagenesis enhances gellan gum production by a novel Sphingomonas spp.: upstream optimization, kinetic modeling, and structural and physico-functional evaluation.
- Author
-
Dev MJ, Mahajan GB, Warke RG, Warke GM, Patil TA, Satardekar MR, Dalvi RC, and Singhal RS
- Subjects
- RNA, Ribosomal, 16S, Fermentation, Polysaccharides, Bacterial, Mutagenesis, Oxygen, Sphingomonas genetics
- Abstract
Gellan gum (GG) has gained tremendous attention owing to its diversified applications. However, its high production and hence market cost are still a bottleneck in its widespread utilization. In the present study, high GG producing mutant of Sphingomonas spp. was developed by random mutagenesis using ethyl methylsulphonate (EMS) for industrial fermentation and identified as Sphingomonas trueperi after 16S rRNA and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) analysis. The fermentation conditions such as pH, temperature, and inoculum ratio were optimized by one factor at a time (OFAT) followed by screening of medium components by the Plackett-Burman statistical design. The most critical nutrients were further optimized by response surface methodology for maximizing GG production. The effect of dissolved oxygen tension in bioreactor on cell growth, substrate consumption, GG production, and batch productivity was elucidated. The highest GG titer (23 ± 2.4 g/L) was attained in optimized medium at 10% inoculum (6.45 ± 0.5 log cfu/mL) under controlled fermentation conditions of pH (7), temperature (30 °C), agitation (300-600 rpm), and aeration (0.5-2.0 SLPM) at 22 ± 2% dissolved oxygen tension in a 10-L bioreactor. Kinetic modeling of optimized batch process revealed that logistic growth model could best explain biomass accumulation, while GG formation and substrate consumption were best explained by Luedeking-Piret and exponential decay model, respectively. Structural and physico-functional features of GG produced by mutant Sphingomonas spp. were characterized by HPLC, FTIR, NMR, DSC, TGA, GPC, SEM, and rheological analysis. The higher productivity (0.51 g/L/h) under optimized fermentation conditions suggests potential consideration of mutant and process for commercial utilization., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
- Published
- 2024
- Full Text
- View/download PDF
9. Mixed Culture Cultivation in Microbial Bioprocesses.
- Author
-
Khedkar M, Bedade D, Singhal RS, and Bankar SB
- Abstract
Mixed culture cultivation is well renowned for industrial applications due to its technological and economic benefits in bioprocess, food processing, and pharmaceutical industries. A mixed consortium encompasses to achieve growth in unsterile conditions, robustness to environmental stresses, perform difficult functions, show better substrate utilization, and increase productivity. Hence, mixed cultures are being valorized currently and has also augmented our understanding of microbial activities in communities. This chapter covers a wide range of discussion on recent improvements in mixed culture cultivation for microbial bioprocessing and multifarious applications in different areas. The history of microbial culture, microbial metabolism in mixed culture, biosynthetic pathway studies, isolation and identification of strains, along with the types of microbial interactions involved during their production and propagation, are meticulously detailed in the current chapter. Besides, parameters for evaluating mixed culture performance, large-scale production, and challenges associated with it are also discussed vividly. Microbial community, characteristics of single and mixed culture fermentation, and microbe-microbe interactions in mixed cultures have been summarized comprehensively. Lastly, various challenges and opportunities in the area of microbial mixed culture that are obligatory to improve the current knowledge of microbial bioprocesses are projected., (© 2024. The Author(s), under exclusive license to Springer Nature Switzerland AG.)
- Published
- 2024
- Full Text
- View/download PDF
10. A supercritical fluid co-extract of turmeric powder and dried coconut shreds shows neuroprotection against AlCl 3 -induced Alzheimer's disease in rats through nose to brain delivery.
- Author
-
Sharma A, Ray A, Sathaye S, and Singhal RS
- Subjects
- Rats, Male, Animals, Aluminum Chloride, Aluminum Compounds adverse effects, Aluminum Compounds metabolism, Chlorides adverse effects, Chlorides metabolism, Curcuma, Powders adverse effects, Powders metabolism, Rats, Wistar, Neuroprotection, Acetylcholinesterase metabolism, Cocos metabolism, Brain metabolism, Alzheimer Disease chemically induced, Alzheimer Disease drug therapy, Alzheimer Disease metabolism
- Abstract
This study was aimed at investigating the neuroprotective potential of a co-extract obtained by supercritical fluid extraction (SFE) of turmeric powder and dried coconut shreds against aluminium chloride (AlCl
3 )-induced Alzheimer's disease (AD) in male Wistar rats. Fifty animals were allocated to five groups, which received saline (vehicle control, group 1), a combination of saline and aluminium chloride (AlCl3 ) (disease control, group 2), coconut oil (COO) (SFE extracted, treatment group 3), turmeric oleoresin (Cur) (SFE extracted, treatment group 4) and SFE co-extract of turmeric powder and coconut shreds (CurCOO) (treatment group 5). Animals were subjected to behavioural evaluation. In addition, the hippocampal section of the brain from all groups was subjected to biochemical, molecular and histopathological evaluations. The results showed CurCOO administered intranasally improved cognitive abilities, reversed histological alterations in the brain, reduced hippocampus inflammation studied through proinflammatory cytokine markers like TNF-α and IL-6 as compared to the disease control group. The impact of CurCOO on preventive neurodegeneration was also observed through a reduction in protein transcription factor NF-kB in the treated group 5 as compared to a disease control group. The effect of intranasal delivery of CurCOO on the neurons responsible for memory consolidation was evident from low acetylcholinesterase (AChE) enzyme activity in the treated groups with respect to AlCl3 induced group. Summarily, the results demonstrated intranasal delivery of CurCOO to show better efficacy than Cur and COO in preventing neurodegeneration associated with AlCl3 induced Alzheimer's disease., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Abhinav Sharma reports financial support was provided by Department of Science and Technology (DST), Government of India. Abhinav Sharma reports a relationship with Department of Science and Technology (DST), Government of India that includes: funding grants. not required., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
11. Inclusion of konjac glucomannan in pea protein hydrogels improved the rheological and in vitro release properties of the composite hydrogels.
- Author
-
Basak S and Singhal RS
- Subjects
- Mannans chemistry, Elasticity, Hydrogels chemistry, Pea Proteins
- Abstract
In this study, a composite hydrogel consisting of pea protein and konjac glucomannan (KG) was fabricated using three approaches, namely neutral, salt-set, and alkaline gelation. Hydrogels made from pea protein were brittle and weak. The addition of KG improved the elasticity and water holding capacity of the pea protein hydrogels. Concomitantly, a decrease in syneresis rate and swelling of the composite hydrogels was observed. The alkaline-set hydrogels exhibited the highest resilience to strain. Thixotropicity was found to be less pronounced for salt-set hydrogels. Sulphate had a greater positive effect on the structural recovery and negative effect on hysteresis area than chloride due to the greater salting-out effect of the sulphates. The addition of KG facilitated the formation of an interconnected structure with limited mobility of biopolymer chains. A sharp increase in G' and G" during the temperature ramp indicated the predominance of hydrophobic interactions towards the aggregation of biopolymers. The infrared spectra of the hydrogels revealed a change in secondary structure of proteins on addition of KG. A controlled in vitro release of riboflavin was observed in neutral and salt-set hydrogels. The alkaline-set hydrogels exhibited a prolonged gastric retention time, thereby establishing in vitro antacid activity in the gastric environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
12. A bigel based formulation protects lutein better in the gastric environment with controlled release and antioxidant profile than other gel based systems.
- Author
-
Kaimal AM and Singhal RS
- Subjects
- Delayed-Action Preparations chemistry, Emulsions, Hydrogels chemistry, Antioxidants, Lutein
- Abstract
Gel based formulations offer an opportunity to fortify bioactives in food. However, a comparative evaluation of gel systems is scantly available. Thus, this study intended to evaluate the impact of various gel formulations (hydrogel, oleogel, emulsion gel, bigels of different compositions) on the delivery and antioxidant activity of lutein. Ethyl cellulose (EC,15 %w/w) and guar-xanthan gum mixture (1:1,1.5 %w/w) was used as oleogelator and hydrogelator, respectively. The microscopic evaluation indicated an oil-based continuous-phase for bigel with 75% oleogel. An increase in oleogel content enhanced textural and rheological properties. An increase in hydrogel composition (25%-75%) of bigel improved the lutein release (70.4%-83.2%). The highest release of lutein was recorded for emulsion gel (84.9%) and bigel with 25% oleogel (83.2%). The antioxidant activity was comparatively lower in gastric medium than simulated intestinal fluid. It could be inferred that the gel matrix significantly affected the lutein release, antioxidant profile, physiochemical and mechanical characteristics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
13. The potential of paraprobiotics and postbiotics to modulate the immune system: A Review.
- Author
-
Mehta JP, Ayakar S, and Singhal RS
- Abstract
Probiotics are viable microorganisms that provide beneficial health effects when consumed in adequate quantity by the host. Immunomodulation is one of the major beneficial effects of probiotics that is a result of the colonization of probiotic microorganisms in the gut, their interaction with the intestinal cells, production of various metabolites and by-products. The last few years have displayed an increasing number of studies on non-viable probiotics (paraprobiotics) and microbial by-products (postbiotics) that prove beneficial to human health by providing positive immune responses even in the inactivated form. The increasing number of research studies compare the effects of viable and non-viable probiotics, their by-products, and metabolites. This review focuses on the ability of different types of paraprobiotics and postbiotics to modulate the immune system. A majority of paraprobiotics are developed from Lactobacillus and Bifidobacterium strains. The postbiotic components that modulate the biological reactions include lipoteichoic acids, bacteriocins, short-chain fatty acids, peptidoglycan, and exopolysaccharides have been reported. We have reviewed paraprobiotics and postbiotics that are commercial as well as in research. Paraprobiotics and postbiotics can be a possible replacement for live probiotics for immunocompromised people. Paraprobiotics display an active role in maintaining T-cell mediated immunity and have been shown to treat colitis. Postbiotic components exhibit properties of pro and anti-immune, anti-tumor, anti-microbial, antioxidant, and anti-biofilm. More research is required on the efficient conversion of probiotics to paraprobiotics, the isolation and purification of different postbiotics, and stability studies during the shelf life. The majority of the articles report the effects of direct ingestion of different '-biotics' without blending in any food product., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier GmbH. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
14. Porous hydrogel composite with whey protein isolate and galactomannans of Leucaena leucocephala (subabul) seeds: Stability, rheological, thermal, and morphological characterization.
- Author
-
Ray A, Sharma A, and Singhal RS
- Subjects
- Whey Proteins chemistry, Carrageenan chemistry, Porosity, Hydrogels, Biocompatible Materials, Seeds, Water, Polysaccharides, Fabaceae
- Abstract
The present study was aimed at curating a porous KCl crosslinked hydrogel with purified subabul galactomannans (SG) from the defatted seeds of Leucaena leucocephala (subabul) and κ-carrageenan (κC) by inducing whey protein isolate (WPI). WPI showed 345% foam overrun and minimal foam drainage (%) at 70°C when whipped for 5 min at pH 6.8 in the hydrogel prepared with 6.5% w/v SG + 1% w/v κC + 0.63% w/v KCl + 2% w/v WPI. The SG and WPI incorporated porous hydrogel (SGWP) showed maximum G' (3010 Pa) and frequency independence (>30 Hz) at 65°C. NMR (
1 H), scanning electron microscopy, and thermal characterization of SGWP showed a crosslinked microporous gel network formation. SGWP had high water uptake rate (Q) (432%) at 45°C. The stability of SGWP at neutral pH and high temperature (65°C) added an impetus to this study as it could be used for a wide range of applications. Hence the protein-polysaccharide complexation improvised the functional properties of the porous hydrogels. The results suggested a possible valorization of galactomannans from subabul, a forest resource, into a porous hydrogel suitable as a matrix for delivery of bioactive(s) or an aerogel for multifarious industrial applications. PRACTICAL APPLICATION: A porous hydrogel is defined as a solid, or collection of solid bodies, with sufficient open space to enable a fluid to pass through or around them. Leucaena leucocephala seed (forest resource) galactomannans are non-starch polysaccharides having weak gelling capacity. Whey protein isolates (WPI) are a dairy industry byproduct having excellent foaming properties. Incorporation of WPI in the hydrogel prepared with subabul galactomannan and κ-carrageenan using KCl as a crosslin could form a stable porous structure having high water uptake rate (Q) at neutral pH and elevated temperature. The hydrogel so developed could be a step toward circular economy., (© 2023 Institute of Food Technologists.)- Published
- 2023
- Full Text
- View/download PDF
15. Investigation into the chemical modification of α-amylase using octenyl succinic anhydride: enzyme characterisation and stability studies.
- Author
-
Danait-Nabar S and Singhal RS
- Subjects
- Tryptophan, Starch chemistry, alpha-Amylases, Succinic Anhydrides chemistry
- Abstract
The present study describes the chemical modification of α-amylase using succinic anhydride (SA), phthalic anhydride (PA) and a novel modifier viz. 2-octenyl succinic anhydride (2-OSA). SA-, PA- and 2-OSA-α-amylases displayed a 50%, 91% and 46% increase in stability at pH 9, respectively; as compared to unmodified α-amylase. PA-α-amylase showed a significant increase in Ea and ΔH
a # , and a concomitant decrease in ΔSa # . The modified α-amylases exhibited improved thermostability as reflected by significant reductions in Kd and ΔSd # , and increments in t1/2 , D-, Ed , ΔHd # and ΔGd # values. The modified α-amylases displayed variable stabilities in the presence of different surfactants, inhibitors, metal ions and organic solvents. Interestingly, the chemical modification was found to confer resistance against inactivation by Hg2+ on α-amylase. The conformational changes in modified α-amylases were investigated using intrinsic tryptophan fluorescence, ANS (extrinsic) tryptophan fluorescence, and dynamic fluorescence quenching. Both intrinsic and extrinsic tryptophan fluorescence spectra showed increased fluorescence intensity for the modified α-amylases. Chemical modification was found to induce a certain degree of structural rigidity to α-amylase, as shown by dynamic fluorescence quenching. Analysis of the CD spectra by the K2d method using the DichroWeb online tool indicated evident changes in the α-helix, β-sheet and random coil fractions of the α-amylase secondary structure, following chemical modification using anhydrides. PA-α-amylase exhibited the highest productivity in terms of hydrolysis of starch at 60 °C over a period of 5 h indicating potential in varied biotechnological applications., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2023
- Full Text
- View/download PDF
16. Advances in fermentative production, purification, characterization and applications of gellan gum.
- Author
-
Dev MJ, Warke RG, Warke GM, Mahajan GB, Patil TA, and Singhal RS
- Subjects
- Bioreactors, Fermentation, Polysaccharides, Bacterial chemistry, Sphingomonas chemistry, Sphingomonas metabolism
- Abstract
Multiple microbial exopolysaccharides have been reported in recent decade with their structural and functional features. Gellan gum (GG) is among these emerging biopolymers with versatile properties. Low production yield, high downstream cost, and abundant market demand have made GG a high cost material. Hence, an understanding on the various possibilities to develop cost-effective gellan gum bioprocess is desirable. This review focuses on details of upstream and downstream process of GG from an industrial perspective. It emphasizes on GG producing Sphingomonas spp., updates on biosynthesis, strain and media engineering, kinetic modeling, bioreactor design and scale-up considerations. Details of the downstream operations with possible modifications to make it cost-effective and environmentally sustainable have been discussed. The updated regulatory criteria for GG as a food ingredient and analytical tools required to validate the same have been briefly discussed. Derivatives of GG and their applications in various industrial segments have also been highlighted., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
17. Food polysaccharides: A review on emerging microbial sources, bioactivities, nanoformulations and safety considerations.
- Author
-
Dedhia N, Marathe SJ, and Singhal RS
- Subjects
- Chemical Phenomena, Drug Delivery Systems, Pharmaceutical Preparations, Antioxidants pharmacology, Polysaccharides chemistry, Polysaccharides pharmacology
- Abstract
The ubiquity, low cost and biocompatibility make polysaccharides a material of choice in food, pharmaceutical, cosmeceutical, textile and paper industries. From the age-old process of pectin addition in jams to the latest developments of bio-nanocomposites with polysaccharides in biosensing, developments in applications of polysaccharides and their derivatives have gone hand-in-hand with the technological progress. This review gives an overview on the recent advances in the use of microbial exopolysaccharides, polysaccharide modifications, conjugation with non-polysaccharide biomolecules, their applications in nutraceutical/drug delivery and their therapeutic potential along with gelled matrices, nanotechnology and packaging advances. The safety, toxicity and potential biological activities such as immunomodulatory, antioxidant, anticancer, hypocholesterolemic, hypoglycemic and prebiotic have been thoroughly reviewed. The ability of polysaccharides and their derivatives in their nano forms coupled with their unique physicochemical properties has been exploited innovatively by researchers globally for applications such as delivery systems for drugs/nutraceuticals/phytochemicals among many others which are also discussed., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
18. Cross-linked β-Mannanase Aggregates: Preparation, Characterization, and Application for Producing Partially Hydrolyzed Guar Gum.
- Author
-
Behera S, Dev MJ, and Singhal RS
- Subjects
- Enzyme Stability, Galactans, Hydrogen-Ion Concentration, Mannans, Plant Gums, Enzymes, Immobilized chemistry, beta-Mannosidase
- Abstract
β-Mannanase capable of hydrolyzing β-1,4-linkages in guar gum was immobilized as cross-linked enzyme aggregates (M-CLEAs). The aggregation and cross-linking process was optimized by response surface methodology (RSM) for maximum activity. The resulting M-CLEAs were characterized by FTIR, DSC, SEM, and SDS-PAGE. The M-CLEAs showed higher pH stability, improved thermal and storage stability, and reusability than free β-mannanase. For example, M-CLEAs were stable over broader pH range (5.5-8.5) with highest relative of activity of 98.17% at pH 6.5 and retained almost double activity than free mannanase at 50 °C after 4 h. Moreover, K
m and Vmax of M-CLEAs were altered significantly, with a 1.5-fold increase and 0.98-fold decrease, respectively, than free β-mannanase. The prepared M-CLEAs could hydrolyze native guar gum (MW = 588,147 Da) to yield partially hydrolyzed guar gum (PHGG) (MW = 8023 Da)., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)- Published
- 2022
- Full Text
- View/download PDF
19. An innovative approach using microencapsulated turmeric oleoresin to develop ready-to-use turmeric milk powder with enhanced oral bioavailability.
- Author
-
Ipar VS, Singhal RS, and Devarajan PV
- Subjects
- Animals, Biological Availability, Milk, Plant Extracts, Powders, Rats, Curcuma, Curcumin
- Abstract
The use of phytochemicals for nutritional wellness has attracted worldwide attention and resulted in development of innovative formulations. Turmeric latte is one such formulation. However, an in-depth study on its physicochemical properties and oral bioavailability has not been conducted as yet. We present a ready-to-use turmeric latte by microencapsulating turmeric oleoresin (TO) with a blend of gum acacia, maltodextrin, and dairy whitener (DW) with bioenhancers by spray drying. The microencapsulated powder obtained exhibited >95% encapsulation efficiency, desired curcumin content, of 539.98 ± 6.56 to 706.40 ± 5.25 mg/100 g, wettability time below 40 s, and dispersibility above 95%. Turmeric latte released >95% of curcumin at pH 1.2 HCl with 0.1% Tween 80, which was ascribed in part to curcumin amorphization as evidenced by DSC and XRD. Turmeric latte demonstrated superior antioxidant activity with 4.2-fold enhanced permeability through non-everted rat intestine and 4.9-fold higher oral bioavailability in rats confirming bioenhancement., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
20. Anti-Angiogenic Effect of Cantharellus cibarius Extracts, its Correlation with Lipoxygenase Inhibition, and Role of the Bioactives Therein.
- Author
-
Marathe SJ, Hamzi W, Bashein AM, Deska J, Seppänen-Laakso T, Singhal RS, and Shamekh S
- Subjects
- Angiogenesis Inhibitors pharmacology, Lipoxygenase, Basidiomycota chemistry, Plant Extracts chemistry, Plant Extracts pharmacology
- Abstract
Angiogenesis is a complex physiological process that cannot be treated with single agent therapy. Several edible fungi have been known to encompass bioactive compounds, and are promising sources of multi-component drugs. One such widely consumed edible fungi is Cantharellus cibarius , which has been explored for its biological activities. The present study focused on assessing the anti-angiogenic activity of petroleum ether and ethanol extracts of C. cibarius using chick chorioallantoic membrane (CAM) assay. Both the extracts showed a dose-dependent response which was compared with the anti-angiogenic activity of the positive controls silibinin, and lenalidomide. The extracts were also studied for their lipoxygenase (LOX) inhibitory potential and compared to ascorbic acid as the positive control. The IC
50 values of the petroleum ether extract, ethanol extract, and ascorbic acid for LOX inhibition assay were 135.4, 113.1, and 41.5 µg/mL, respectively. Although both the extracts showed similar responses in CAM assay, ethanol extract proved to be more potent in LOX inhibition assay. Finally, the extracts were investigated for their chemical composition using GC-MS. A correlation between LOX inhibition and anti-angiogenic potential was established at the molecular level. A meticulous literature search was carried out to correlate the biochemical composition of the extracts to their anti-angiogenic activity.- Published
- 2022
- Full Text
- View/download PDF
21. Encapsulation of ginger oleoresin in co-crystallized sucrose: development, characterization and storage stability.
- Author
-
Rai K, Chhanwal N, Shah NN, and Singhal RS
- Subjects
- Catechols chemistry, Chromatography, High Pressure Liquid, Crystallization, Drug Compounding, Drug Stability, Drug Storage, Fatty Alcohols chemistry, Kinetics, Temperature, Zingiber officinale chemistry, Plant Extracts chemistry, Sucrose chemistry
- Abstract
Ginger oleoresin was emulsified with gum acacia and encapsulated in a sucrose matrix by co-crystallization. The increased void space and surface area of sucrose provided a porous base for the incorporation of oleoresin. This co-crystallization led to modification from crystalline to irregular agglomerates, as evident from X-ray diffraction and differential scanning calorimetry. Hygroscopicity, water sorption isotherms and water activity demonstrated changes due to the change in crystallinity of sucrose. The active components such as [6]-, [8]- and [10]-gingerols and [6]-shogaol were quantified by HPLC. The encapsulation efficiency of [6]-gingerol was 45.59%. The storage kinetics at different relative humidity levels and temperatures indicated [6]-gingerol to be the most stable among the gingerols studied. A temperature of 25 °C and relative humidity of 33% proved to be the best storage conditions for the ginger flavoured sugar cubes. Thus, co-crystallization for the encapsulation of ginger oleoresin serves a dual purpose, i.e., protection and a mode of delivering a spicy flavour.
- Published
- 2021
- Full Text
- View/download PDF
22. Preparation of cross-linked enzyme aggregates of lipase from Aspergillus niger: process optimization, characterization, stability, and application for epoxidation of lemongrass oil.
- Author
-
Muley AB, Awasthi S, Bhalerao PP, Jadhav NL, and Singhal RS
- Subjects
- Biocatalysis, Culture Media chemistry, Enzyme Stability, Enzymes, Immobilized chemistry, Epoxy Compounds chemistry, Glutaral chemistry, Hydrogen-Ion Concentration, Industrial Microbiology methods, Iodine chemistry, Kinetics, Particle Size, Spectroscopy, Fourier Transform Infrared, Temperature, Thermodynamics, Aspergillus niger enzymology, Biotechnology methods, Cross-Linking Reagents chemistry, Lipase chemistry, Plant Oils chemistry, Terpenes chemistry
- Abstract
Cross-linked enzyme aggregates (CLEAs) of lipase were prepared after fractional precipitation with 40-50% ammonium sulfate and then cross-linking with glutaraldehyde. The process variables for the preparation of lipase-CLEAs such as glutaraldehyde concentration, cross-linking period, and initial pH of medium were optimized. The optimized conditions for the preparation of lipase-CLEAs were 25 mM/80 min/pH 7.0, and 31.62 mM/90 min/pH 6.0 with one factor at a time approach and numerical optimization with central composite design, respectively. Lipase-CLEAs were characterized by particle size analysis, SEM, and FTIR. Cross-linking not only shifted the optimal pH and temperature from 7.0 to 7.5 and 40-45 to 45-50 °C, but also altered the secondary structure. Lipase-CLEAs showed an increase in K
m by 7.70%, and a decrease in Vmax by 16.63%. Lipase-CLEAs presented better thermostability than free lipase as evident from thermal inactivation constants (t1/2 , D and Ed value), and thermodynamic parameters (Ed , ΔH°, ΔG°, and ΔS°) in the range of 50-70 °C. Lipase-CLEAs retained more than 65% activity up to four cycles and showed good storage stability for 12 days when stored at 4 ± 2 °C. They were successfully utilized for the epoxidation of lemongrass oil which was confirmed by changes in iodine value, epoxide value, and FTIR spectra.- Published
- 2021
- Full Text
- View/download PDF
23. Enzymatic response of Moina macrocopa to different sized zinc oxide particles: An aquatic metal toxicology study.
- Author
-
Borase HP, Muley AB, Patil SV, and Singhal RS
- Subjects
- Animals, Ecosystem, Lethal Dose 50, Cladocera, Water Pollutants, Chemical analysis, Water Pollutants, Chemical toxicity, Zinc Oxide toxicity
- Abstract
Zinc oxide particles (ZnOPs) of both nanometer and sub-micron sizes are important components of high demand consumer products such as sunscreen, paint, textile, food packaging, and agriculture. Their ultimate discharge in the aquatic ecosystem is nearly unavoidable. For sustainable use of ZnOPs, there is an urgent need to assess its ecotoxicity using ecological indicator organisms. Moina macrocopa, an important component of the aquatic ecosystem is one such less explored indicator organism. In the present investigation, ZnOPs of two different sizes (250 ± 20 and 500 ± 50 nm) were selected for risk assessment as most of the previous reports were based on the use of 10-100 nm ZnOPs. ZnOPs of 500 nm were more lethal than that of 250 nm size, with respective LC
50 of 0.0092 ± 0.0012 and 0.0337 ± 0.0133 mg/L against M. macrocopa after 48 h of exposure. We further used a sublethal concentration of 500 nm (0.00336 mg/L) and 250 nm (0.00092 mg/L) ZnOPs followed by measurement of enzymatic biomarkers of toxicity (acetylcholinesterase, digestive enzymes, antioxidant enzymes). A size-dependent variation in enzymatic response to 250 and 500 nm ZnOPs was seen. Exposure to ZnOPs inhibited acetylcholinesterase and digestive enzymes (trypsin, amylase), and elevated antioxidant enzymes (catalase, glutathione S-transferase) levels. The exposure also decreased the superoxide dismutase activity and increased that of β-galactosidase. Microscopic investigation revealed the accumulation of ZnOPs in the digestive tract of M. macrocopa that possibly disrupts enzyme activities. The present study will contribute to establishing regulatory policy on the maximum permissible limit of ZnOPs in different water bodies., (Copyright © 2020 Elsevier Inc. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
24. Co-encapsulation of vitamins B 12 and D 3 using spray drying: Wall material optimization, product characterization, and release kinetics.
- Author
-
Bajaj SR, Marathe SJ, and Singhal RS
- Subjects
- Biological Availability, Capsules chemistry, Gum Arabic chemistry, Kinetics, Cholecalciferol chemistry, Drug Compounding methods, Vitamin B 12 chemistry
- Abstract
Spray drying is the most commonly used encapsulation technique to stabilize sensitive bioactive compounds and sometimes enhances their performance. Vitamin B
12 and vitamin D3 deficiencies are reported worldwide and co-encapsulation can provide a combined solution to this problem. The present work aimed at encapsulation of vitamin B12 and D3 by spray drying using experimental design to optimize wall material combination. Optimized solution obtained from the experimental design (gum acacia : Hi-Cap® 100 : maltodextrin = 38:60:2) provided spherical particles with smooth surface and better stability of both the vitamins. In vitro release mechanism showed a slow release for both the vitamins after encapsulation. The optimized co-encapsulated microcapsules obtained in this work showed an improved bioavailability of 151% for vitamin B12 and 109% for vitamin D3 in comparison with the control. This study delivered a suitable medium to provide water soluble vitamin B12 and fat soluble vitamin D3 in single product., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
25. Anti-angiogenic and anti-inflammatory activity of the summer truffle (Tuber aestivum Vittad.) extracts and a correlation with the chemical constituents identified therein.
- Author
-
Marathe SJ, Hamzi W, Bashein AM, Deska J, Seppänen-Laakso T, Singhal RS, and Shamekh S
- Subjects
- Anti-Inflammatory Agents pharmacology, Plant Extracts pharmacology, Solvents, Ascomycota
- Abstract
Fungi are a huge source of unexplored bioactive compounds. Owing to their biological activities, several fungi have shown commercial application in the health industry. Tuber aestivum Vittad. is one such edible fungi with an immense scope for practical biological applications. In the present study, the anti-angiogenic activity of petroleum ether and ethanol extracts of T. aestivum was investigated using the chick chorioallantoic membrane assay and compared to the positive controls silibinin and lenalidomide. Both the extracts showed a dose-dependent anti-angiogenic response. The extracts were also assessed for their anti-inflammatory potential by lipoxygenase-inhibition assay. The IC
50 values for LOX inhibition assay, computed by the Boltzmann plot, were 368.5, 147.3 and 40.2 µg/mL, for the petroleum ether extract, ethanol extract, and the positive control ascorbic acid, respectively. The ethanol extract of T. aestivum showed superior anti-angiogenic and anti-inflammatory activity than the petroleum ether extract. Compositional investigation of the extracts by GC-MS revealed the presence of various bioactive compounds. The compounds were correlated to their anti-angiogenic and anti-inflammatory activity based on a meticulous literature search., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
26. Extension of postharvest shelf life of strawberries (Fragaria ananassa) using a coating of chitosan-whey protein isolate conjugate.
- Author
-
Muley AB and Singhal RS
- Subjects
- Antioxidants chemistry, Ascorbic Acid analysis, Calorimetry, Differential Scanning, Color, Fragaria chemistry, Fragaria metabolism, Fruit chemistry, Fruit metabolism, Glycerol chemistry, Hydrogen-Ion Concentration, Phenols analysis, Spectroscopy, Fourier Transform Infrared, Temperature, Chitosan chemistry, Food Preservation methods, Whey Proteins chemistry
- Abstract
Chitosan and whey protein isolate (WPI) conjugate films were prepared as a novel matrix for encapsulating and extending the postharvest shelf life of strawberries. Film forming solutions of chitosan, WPI, and chitosan-WPI conjugate were mixed with glycerol, casted for films at 60 ± 2 °C and assessed for their colour, water vapour and oxygen transfer rate, textural, functional groups and secondary structure, thermal, crystallinity, and antioxidant properties. Chitosan-WPI conjugate films were applied as an edible coating on strawberries, and studied for storage stability at 5 °C and 20 °C by assessing physical and biochemical parameters. A considerable reduction in colour indices, weight loss, pH and titratable acidity, reducing sugars, ascorbic acid, total phenolics, DPPH and ABTS assay was noted in the coated strawberries over the control at both the studied temperatures. The control strawberries had a shelf life of 5 and 3 days, whereas coating enhanced the shelf life of strawberries to 8 and 5 days when stored at 5 °C and 20 °C, respectively., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
27. Enhancement of loading and oral bioavailability of curcumin loaded self-microemulsifying lipid carriers using Curcuma oleoresins.
- Author
-
Vijayan UK, Varakumar S, Sole S, and Singhal RS
- Subjects
- Administration, Oral, Animals, Biological Availability, Drug Delivery Systems, Emulsions, Rats, Rats, Wistar, Solubility, Curcuma chemistry, Curcumin, Lipids chemistry, Plant Extracts chemistry
- Abstract
The therapeutic applications of curcumin, a phenolic compound extracted from Curcuma species, is limited due to poor bioavailability. To enhance the bioavailability, self-microemulsifying drug delivery systems (SMEDDS) with curcumin were prepared. Ethyl oleate, Tween 80, and Transcutol
® P with surfactant: co-surfactant ratio of 2:1 w/w was selected based on the solubility and pseudo-ternary phase diagrams. The optimized formulation (S-Eo3) was evaluated for use of spice oleoresins as curcumin bioenhancers. The oleophilic phase of curcumin containing SMEDDS formulations was then successfully modified by using bioactive oleoresins extracted from two Curcuma species, viz. C. longa (S-CL1) and C. aromatica (S-CA1). The curcumin content in S-Eo3, S-CL1, and S-CA1 were 69.6 ± 0.23, 82.4 ± 0.62, and 88.8 ± 0.46 mg/g, respectively. Thus, by the partial modification of oleophilic phase of SMEDDS with spice oleoresin (acting as bioenhancer) resulted in ∼88 k improvement of curcumin aqueous solubility. The pharmacokinetic study in male Wistar rats showed that the relative bioavailability of curcumin in S-CL1 and S-CA1 were 26- and 29-fold vis-à-vis 22-fold in S-Eo3 compared to curcumin suspension. All the SMEDDS formulations were stable for three months as established by ICH guidelines.- Published
- 2020
- Full Text
- View/download PDF
28. Cross-linked enzyme aggregates of arylamidase from Cupriavidus oxalaticus ICTDB921: process optimization, characterization, and application for mitigation of acrylamide in industrial wastewater.
- Author
-
Kulkarni NH, Muley AB, Bedade DK, and Singhal RS
- Subjects
- Enzyme Stability, Acrylamide chemistry, Amidohydrolases chemistry, Amidohydrolases isolation & purification, Bacterial Proteins chemistry, Bacterial Proteins isolation & purification, Cupriavidus enzymology
- Abstract
Acrylamidase produced by Cupriavidus oxalaticus ICTDB921 was recovered directly from the fermentation broth by ammonium sulfate (40-50%) precipitation and then stabilized by cross-linking with glutaraldehyde. The optimum conditions for the preparation of cross-linked enzyme aggregates of acrylamidase (acrylamidase-CLEAs) were using 60 mM glutaraldehyde for 10 min at 35 °C and initial broth pH of 7.0. Acrylamidase-CLEAs were characterized by SDS-PAGE, FTIR, particle size analyzer and SEM. Cross-linking shifted the optimal temperature and pH from 70 to 50 °C and 5-7 to 6-8, respectively. It also altered the secondary structure fractions, pH and thermal stability along with the kinetic constants, K
m and Vmax , respectively. A complete degradation of acrylamide ~ 1.75 g/L in industrial wastewater was achieved after 60 min in a batch process under optimum operating conditions, and the kinetics was best represented by Edward model (R2 = 0.70). Acrylamidase-CLEAs retained ~ 40% of its initial activity after three cycles for both pure acrylamide and industrial wastewater, and were stable for 15 days at 4 °C, retaining ~ 25% of its original activity.- Published
- 2020
- Full Text
- View/download PDF
29. Enzymatic synthesis of fatty acid esters of trehalose: Process optimization, characterization of the esters and evaluation of their bioactivities.
- Author
-
Marathe SJ, Shah NN, and Singhal RS
- Subjects
- Anti-Bacterial Agents chemistry, Anti-Bacterial Agents metabolism, Anti-Inflammatory Agents, Non-Steroidal chemistry, Anti-Inflammatory Agents, Non-Steroidal metabolism, Arachidonate 15-Lipoxygenase metabolism, Basidiomycota enzymology, Biocatalysis, Dose-Response Relationship, Drug, Escherichia coli drug effects, Esters chemistry, Esters metabolism, Humans, Microbial Sensitivity Tests, Molecular Structure, Palmitic Acid chemistry, Palmitic Acid metabolism, Pseudomonas aeruginosa drug effects, Staphylococcus aureus drug effects, Structure-Activity Relationship, Trehalose chemistry, Trehalose metabolism, Anti-Bacterial Agents pharmacology, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Esters pharmacology, Lipase metabolism, Palmitic Acid pharmacology, Trehalose pharmacology
- Abstract
One-pot synthesis of caprylic, lauric and palmitic acid mono- and diesters of trehalose was catalyzed by the lipase Fermase CALB™ 10000. An optimized molar conversion of 35% of trehalose to its palmitate esters was obtained in acetone at 60 °C with a trehalose:palmitic acid molar ratio of 1:5 in 4 h. Trehalose fatty acid esters (THFAE) were purified by column chromatography and characterized using TLC, HPTLC, HR-MS, ATR-FTIR, and differential scanning calorimetry. THFAE were studied for their antimicrobial potential against four bacterial, and two fungal species. Trehalose monolaurate and trehalose dicaprylate demonstrated MIC of 0.45 mM and 16 mM against Pseudomonas aeruginosa and Escherichia coli, respectively. Trehalose monocaprylate showed the highest inhibition of biofilm forming property against Staphylococcus aureus (86.25%) at 99.2 mM and trehalose dipalmitate had lowest IC50 of 13.23 mM. Furthermore, their anti-inflammatory property was studied in vitro using 15-LOX inhibition assay and human red blood cell membrane stabilization assay. In the confirmatory in vivo tests using carrageenan-induced rat paw edema assay, inflammation in disease control group reached up to 63% as against 32% and 20% for trehalose dilaurate and diclofenac treated groups, respectively. THFAE can hence find potential applications in pharmaceuticals, functional foods, and nutraceuticals., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
30. Immobilization of enzymes on iron oxide magnetic nanoparticles: Synthesis, characterization, kinetics and thermodynamics.
- Author
-
Muley AB, Mulchandani KH, and Singhal RS
- Subjects
- Animals, Cellulase chemistry, Enzyme Assays methods, Enzyme Stability, Humans, Kinetics, Nanotechnology methods, Propylamines chemistry, Silanes chemistry, Surface Properties, Thermodynamics, Enzymes, Immobilized chemistry, Magnetic Iron Oxide Nanoparticles chemistry
- Abstract
Immobilization of enzymes on matrices like iron oxide magnetic nanoparticles provides a new technique against the stagnant conventional approaches for stabilization of enzymes. Along with ease in synthesis and modification, the advantages of using these iron oxide nano-metallic matrices as enzyme support matrices are three dimensional viz. structural and thermal stability, storage stability, and reusability. This book chapter details the protocol(s) for synthesis of iron oxide magnetic nanoparticles via chemical co-precipitation method, its surface modification and functionalization with 3-aminopropyl-triethoxysilane (APTES), followed by immobilization of enzymes using glutaraldehyde as a cross linker. A detailed protocol for instrumental characterization is also described. Additionally, the chapter also elucidates the basic characterization of enzyme(s), effect of operating conditions (pH, temperature) on the enzyme activity, thermal inactivation kinetics, thermodynamic parameters, storage stability, and reusability of the free and immobilized enzymes. Further, the results of all the indicated protocols and stability studies are thoroughly discussed with the findings on immobilization of cellulase in a tri-enzyme mixture on iron oxide magnetic nanoparticles. The optimum parameters for immobilization were 30mM glutaraldehyde with 3h incubation and 3:1 (w/w) ratio of nanoparticles:protein content. Immobilization altered the kinetic constants (K
m and Vmax ) marginally but enhanced the thermal stability as evident from inactivation kinetic constants (kd , t1/2 and D-value) and thermodynamic parameters (Ed , ΔH°, ΔG° and ΔS°) within 55-75°C. The immobilized cellulase retained 71.68±3.48% activity during 21-day storage, and 81.15±5.27% activity till fifth reusability cycle., (© 2020 Elsevier Inc. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
31. Influence of food commodities on hangover based on alcohol dehydrogenase and aldehyde dehydrogenase activities.
- Author
-
Srinivasan S, Dubey KK, and Singhal RS
- Abstract
Alcohol consumption often leads to hangover, a condition characterized by several symptoms, characteristically headache, nausea, fatigue and drowsiness. Hangover may be alleviated by altering the rate of alcohol metabolism and facilitating elimination of acetaldehyde by affecting the activity of alcohol dehydrogenase (ADH) and/or aldehyde dehydrogenase (ALDH) enzymes. In the present study, several food commodities like fruits, vegetables, cereals, pulses, dairy products, spices and other miscellaneous products (ascorbic acid, cocoa sample, tea, coffee, egg yolk and date samples) were investigated for their effect on the in vitro activities of the enzymes and their antioxidant properties. Of the many screened food commodities, few showed an increase in the activity of either one or both the enzymes, ADH and ALDH. Studies showed no correlation between ADH and ALDH enzyme activities and antioxidant property of the selected food commodities for anti-hangover effect. Further, an anti-hangover (AHO) product was developed using pear (65%), sweet lime (25%) and coconut water (10%) and, validated for in vitro ADH and ALDH enzyme activities. AHO product was found to enhance ADH and ALDH activities by 23.31% and 70.02%, respectively., (© 2019 The Authors.)
- Published
- 2019
- Full Text
- View/download PDF
32. Stabilization of cutinase by covalent attachment on magnetic nanoparticles and improvement of its catalytic activity by ultrasonication.
- Author
-
Muley AB, Chaudhari SA, Bankar SB, and Singhal RS
- Abstract
This paper reports on stabilization of serine cutinase activity by immobilizing it through cross linking with glutaraldehyde on magnetic nanoparticles (Fe-NPs) and intensification of catalytic activity by ultrasonic treatment. The optimum parameters were cross linking with 10.52 mM glutaraldehyde for 90 min using 1:2 (w/w) ratio of enzyme:Fe-NPs. The characterization of cutinase-Fe-NPs was done by different instrumental analysis. Ultrasonic power showed a beneficial effect on the activity of free and immobilized cutinase at 5.76 and 7.63 W, respectively, after 12 min. Immobilization and ultrasonic treatment led to increments in kinetic parameters (K
m and Vmax ) along with noticeable changes in the secondary structural fractions of cutinase. Cutinase-Fe-NPs showed augmented pH (4-8) and thermal stability (40-60 °C). Considerably higher thermal inactivation kinetic constants (kd , t1/2 and D-value) and thermodynamic constants (Ed , ΔH°, ΔG° and ΔS°) highlighted superior thermostability of cutinase-Fe-NPs. Cutinase-Fe-NPs and ultrasound treated cutinase-Fe-NPs retained 61.88% and 38.76% activity during 21-day storage, and 82.82 and 80.69% activity after fifth reusability cycle, respectively., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
33. Nano-eco toxicity study of gold nanoparticles on aquatic organism Moina macrocopa: As new versatile ecotoxicity testing model.
- Author
-
Borase HP, Muley AB, Patil SV, and Singhal RS
- Subjects
- Acetylcholinesterase metabolism, Amylases metabolism, Animals, Behavior, Animal drug effects, Catalase metabolism, Cladocera physiology, Glutathione Transferase metabolism, Heart Rate drug effects, Lethal Dose 50, Superoxide Dismutase metabolism, Toxicity Tests methods, Trypsin metabolism, Cladocera drug effects, Gold toxicity, Metal Nanoparticles toxicity, Water Pollutants, Chemical toxicity
- Abstract
In the field of nanoecotoxicology, very few reports have focused on biochemical changes in non-target organisms after nanoexposure. A less explored aquatic non-target crustacean, Moina macrocopa, was used in the present study to analyze toxicity effects of gold nanoparticles (AuNPs), an emerging nanomaterial. AuNPs was fabricated using tannic acid and were 29 ± 2 nm in size. The 48 h LC
50 value of AuNPs was 14 ± 0.14 mg/L against M. macrocopa. The sub-lethal exposure of M. macrocopa juveniles to AuNPs (1.47 and 2.95 mg/L) decreased the activities of acetyl cholinesterase and digestive enzymes (trypsin and amylase). A concentration dependant increase in the activities of antioxidant enzymes such as catalase, superoxide dismutase and glutathione S-transferase suggested the generation of oxidative stress in M. macrocopa after AuNPs exposure. Changes in enzyme activity can be utilized as biomarker(s) for early detection of nanoparticle contamination in aquatic habitat. AuNPs accumulation in gut of M. macrocopa increased the metal bio burden (11 mg/L) and exhibited inhibitory action on digestive enzymes. Complete depuration of AuNPs was not observed after transferring nano-exposed M. macrocopa to normal medium without AuNPs. AuNPs tended to adhere on external body parts such as setae, carapace of M. macrocopa which interfered with swimming activity and also changed the behavioral pattern. AuNPs underwent agglomeration in the medium used for maintenance of M. macrocopa. As nanomaterials are emerging pollutants in aquatic systems, the present work highlights the hazardous effect of AuNPs and development of enzymatic biomarkers to curtail it at community level., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
34. Chitosan coated calcium alginate beads for covalent immobilization of acrylamidase: Process parameters and removal of acrylamide from coffee.
- Author
-
Bedade DK, Sutar YB, and Singhal RS
- Subjects
- Burkholderiaceae enzymology, Carbodiimides chemistry, Enzymes, Immobilized metabolism, Food Handling instrumentation, Hydrogen-Ion Concentration, Kinetics, Microscopy, Electron, Scanning, Spectroscopy, Fourier Transform Infrared, Succinimides chemistry, Temperature, Acrylamide isolation & purification, Alginates chemistry, Amidohydrolases chemistry, Chitosan chemistry, Coffee chemistry, Enzymes, Immobilized chemistry, Food Handling methods
- Abstract
This study reports on removal of acrylamide from roasted coffee by acrylamidase from Cupriavidus oxalaticus ICTDB921. Chitosan coated calcium alginate beads were functionalized with citric acid as nontoxic cross linker and activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) (1.66:1 w/w) for covalent immobilization of acrylamidase. The optimum beads were obtained using 5% sodium alginate, 1.5% chitosan, and 0.6 mol/L citric acid. The beads prepared at each step were characterized by FTIR and SEM. Coating of chitosan matrix on calcium alginate beads enhanced the mechanical stability over that of calcium alginate and/or chitosan. The immobilized acrylamidase showed optimum pH/temperature of 8.5/65 °C, improved pH/thermal/shelf stability, and retained 80% activity after four cycles. Haldane model could describe the degradation kinetics of acrylamide in batch study. In packed bed column, a bed height, feed flow rate and inlet acrylamide concentration of 20 cm, 1 mL/min, and 100 mg/L gave best results., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
35. Moina macrocopa as a non-target aquatic organism for assessment of ecotoxicity of silver nanoparticles: Effect of size.
- Author
-
Borase HP, Patil SV, and Singhal RS
- Subjects
- Animals, Antioxidants metabolism, Aquatic Organisms drug effects, Ecotoxicology methods, Oxidoreductases metabolism, Particle Size, Silver toxicity, Cladocera drug effects, Metal Nanoparticles toxicity
- Abstract
The release of nanomaterials in water reservoirs is hazardous. Very few reports are available on the interaction of different sized nanoparticles with aquatic organisms and aquatic environment. In the present study, silver nanoparticles (AgNPs) having an average particle size of 20.80 ± 2.31 and 40.04 ± 4.72 nm were synthesized using polyvinylpyrrolidone and l-tyrosine. Ecotoxicological effects of AgNPs were evaluated on less explored crustacean species, Moina macrocopa. The 48 h lethal values (48 h LC
50 ) of 20 and 40 nm AgNPs were 0.11 ± 0.02 and 0.12 ± 0.03 mg/L, respectively. Further, a size dependent inhibition of AgNPs on acetyl cholinesterase and digestive enzymes (trypsin, amylase, β-galactosidase) was observed, while that of the antioxidant enzymes (catalase, superoxide dismutase, glutathione-S-transferase) and alkaline phosphatase were enhanced as compared to control group. These results strengthen the potential of enzymes as biomarker in environmental risk assessment of AgNPs. AgNPs accumulated in the gut of M. macrocopa which could not be completely eliminated, thereby resulting in an increased metal body burden. The accumulation of AgNPs of 20 nm was lower than that of 40 nm indicating the influence of size of nanoparticles on uptake and toxicity. AgNPs agglomerated in moderately hard water medium (MHWM) and this agglomeration influenced the exposure the organism thereto. The size of AgNPs influenced the toxicity to M. macrocopa through interplay between uptake, accumulation, aggregation, and excretion in the organism and environment., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
36. Magnetic cross-linked enzyme aggregates of acrylamidase from Cupriavidus oxalaticus ICTDB921 for biodegradation of acrylamide from industrial waste water.
- Author
-
Bedade DK, Muley AB, and Singhal RS
- Subjects
- Industry, Kinetics, Magnetics, Magnetite Nanoparticles, Temperature, Thermodynamics, Acrylamide metabolism, Cupriavidus enzymology, Industrial Waste, Wastewater chemistry
- Abstract
Acrylamidase from Cupriavidus oxalaticus ICTDB921 was immobilized on magnetic nanoparticles (MNPs) for degradation of acrylamide (a group 2A carcinogen and an environmental contaminant) from industrial waste water. Acrylamidase-MNPs were prepared (maximum recovery ∼94%) at optimized process parameters viz. 1.5:1 (v/v) of acetone: crude acrylamidase/5 mM of glutaraldehyde/90 min/1.5:1 of enzyme: MNP ratio. MNPs and acrylamidase-MNPs were characterized by particle size analysis, FTIR, XRD, SEM and vibrating sample magnetometer. Acrylamidase-MNPs showed a shift in optimum pH (8-8.5) and temperature (60-65 °C) with higher pH/thermal stability vis-à-vis free enzyme. A significant increase in kinetic constants, thermal inactivation constants and thermodynamic parameters were noted for acrylamidase-MNPs. A complete degradation of acrylamide ∼2100 mg/L was achieved in industrial waste water under optimized conditions for batch process and the kinetics was best represented by Haldane model. Acrylamidase-MNPs retained >80% of its initial activity after 4 cycles for both pure acrylamide and industrial waste water., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
37. A tri-enzyme co-immobilized magnetic complex: Process details, kinetics, thermodynamics and applications.
- Author
-
Muley AB, Thorat AS, Singhal RS, and Harinath Babu K
- Subjects
- Cellulase chemistry, Endo-1,4-beta Xylanases chemistry, Enzyme Activation, Enzyme Stability, Hydrogen-Ion Concentration, Kinetics, Polygalacturonase chemistry, Spectroscopy, Fourier Transform Infrared, Temperature, Thermodynamics, Enzymes, Immobilized chemistry, Magnetite Nanoparticles chemistry, Multienzyme Complexes chemistry
- Abstract
A tri-enzyme mixture of cellulase, pectinase and xylanase present in fermentation broth of Aspergillus niger culture was directly recovered by solvent precipitation and co-immobilized on magnetic nanoparticles (MNPs) by cross linking with glutaraldehyde. A 2:1 ratio of isopropanol:total protein in the fermentation broth gave a precipitate with maximal activity recovery of the three enzymes. The co-immobilization on MNPs was optimized at 30 mM glutaraldehyde for 3 h incubation, and 3:1 MNPs:enzyme ratio, yielding a maximum activity recovery of cellulase (80.25 ± 1.03%), pectinase (84.76 ± 1.71%) and xylanase (75.62 ± 0.76%), respectively. The tri-enzyme co-immobilized MNPs were characterized by particle size analysis, FTIR, XRD, VSM and SEM studies, and showed enhanced thermal stability as evident from lower k
d , higher t1/2 and D-value in the range of 55-75 °C. The tri-enzyme co-immobilized MNPs showed a shift in optimum temperature from 55 to 60 °C with improved pH tolerance along with a slender rise in kinetic constants and enhanced thermodynamic parameters. It was stable for 36 days at 5 °C, and retained >90% activity up to 4 cycles. The tri-enzyme co-immobilized MNPs were successfully utilized for extraction of piperine from black pepper, preparation of sugarcane cell protoplasts, and clarification of papaya juice with prominent yield and reusability vis-à-vis traditional methods., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
38. Debittering of bitter gourd juice using β-cyclodextrin: Mechanism and effect on antidiabetic potential.
- Author
-
Deshaware S, Gupta S, Singhal RS, Joshi M, and Variyar PS
- Subjects
- Antioxidants analysis, Female, Humans, Hypoglycemic Agents pharmacology, Male, Phenols analysis, Sequestering Agents chemistry, Fruit and Vegetable Juices analysis, Hypoglycemic Agents analysis, Momordica charantia chemistry, Saponins chemistry, Taste, beta-Cyclodextrins chemistry
- Abstract
Triterpene glycosides namely momordicoside K and momordicoside L causes bitterness in bitter-gourd thereby reducing its consumer acceptance. Reducing bitterness of the juice by addition of β-cyclodextrin (0.25-2%) was attempted and its effect on sensory quality, total phenolic content, antioxidant activity and antidiabetic potential was evaluated. Juice with 1.5% β-cyclodextrin demonstrated highest score (7.7 ± 0.3) for sensory acceptability compared to the control (3.8 ± 0.7). A significantly (p < 0.05) higher total phenolic content and antioxidant activity was observed. A marginal (10%) but significant (p < 0.05) reduction in α-glucosidase inhibition activity without affecting α-amylase activity was noted. Results from NMR, ROESY and FTIR studies indicated formation of an inclusion complex by interaction of hydrophobic triterpenoidal region of momordicosides with β-cyclodextrin., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
39. Biodegradation of acrylamide by a novel isolate, Cupriavidus oxalaticus ICTDB921: Identification and characterization of the acrylamidase produced.
- Author
-
Bedade DK and Singhal RS
- Subjects
- Amides, Biodegradation, Environmental, RNA, Ribosomal, 16S, Acrylamide metabolism, Cupriavidus
- Abstract
Acrylamide is neurotoxic, genotoxic, teratogenic and carcinogenic. Its widespread use in various industrial processes leads to environmental contamination. Acrylamidase produced by certain bacteria degrade acrylamide to acrylic acid and ammonia. The present study details the isolation and identification of soil bacterium which could degrade acrylamide. Among the 18 acrylamide-degrading isolates tested, isolate ICTDB921 demonstrated superior acrylamide degradation which was confirmed by HPLC, FTIR and GC-MS. The partial 16S rRNA sequencing confirmed the isolate to be Cupriavidus oxalaticus ICTDB921, which showed highest growth at 60 mM acrylamide, neutral pH and 30 °C. The kinetic model predictions were consistent with experimental results. The acrylamidase from this isolate showed potency at pH (6-8) and temperatures (30-60 °C), with reasonable pH (6-8) and thermal stability (upto 60 °C). The enzyme was stable against most metal ions and amino acids, and also degraded other aliphatic amides, demonstrating its potential in remediation of acrylamide from the environment and food systems., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
40. Extraction and characterization of chitosan from prawn shell waste and its conjugation with cutinase for enhanced thermo-stability.
- Author
-
Muley AB, Chaudhari SA, Mulchandani KH, and Singhal RS
- Subjects
- Animal Shells chemistry, Animals, Chitosan isolation & purification, Chitosan pharmacology, Decapoda chemistry, Enzyme Stability drug effects, Molecular Weight, Thermodynamics, Antioxidants chemistry, Carboxylic Ester Hydrolases chemistry, Chitosan chemistry
- Abstract
The present article describes extraction of chitosan from prawn shells waste and its application in thermal stabilization of Fusarium sp. ICT SAC1 cutinase by non-covalent and covalent conjugation. Extracted chitosan represented 78.40% degree of deacetylation (DDA), a molecular weight of 173 kDa and was soluble in 1% acetic acid with 2.8 ± 0.15% insoluble matter. The structural (FTIR, NMR and XRD) and thermal characterization (DSC and TGA) indicated unique properties for chitosan. Plausible chitosan structure was also deduced. The water and fat binding capacities were 923% and 598.05% while 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and 1,1-diphenyl-2-picrylhydrzyl radicals scavenging activity was 60.62 and 11.83 μM Trolox-Equivalent/ml. The K
m and Vmax values of free cutinase were 0.82 mM and 20.64 mM/min which increased by 14.63 and 17.07%; and 27.18 and 43.94% after non-covalent and covalent conjugation, respectively. A marginal increment in thermal inactivation constants and energy (kd , t1/2 , D and Ed value) were also noticed for cutinase-chitosan conjugates. The enthalpy, free energy and entropy values increased marginally in covalent conjugate vis-à-vis non-covalent conjugated and free cutinase. A reduction in α-helix, random coils and β-sheets content was noted after conjugation., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
41. Evaluation and application of prebiotic and probiotic ingredients for development of ready to drink tea beverage.
- Author
-
Tewari S, Dubey KK, and Singhal RS
- Abstract
Ready-to-drink (RTD) ice tea is a ready prepared tea, produced from green and black tea originating from same plant Camellia sinensis . The objective of this study was to determine the effect of prebiotics [galacto-oligosaccharide (GOS), fructo-oligosaccharide (FOS), and inulin] or synbiotic ingredients (GOS, FOS, inulin, and Lactobacillus acidophilus ) on the sensory properties and consumer acceptability of RTD. The quality of green tea extract (GTE) and black tea extract (BTE) was improved with pretreatment of cellulase and pectinase enzymes. The combined enzymatic extraction amplified total extractives up to 76% in GTE and 72% in BTE. Total polyphenol was found to be enhanced to 24% in GTE and 19% in BTE. GTE was further selected for development of RTD in two different formats; synbiotic RTD and prebiotic RTD premix and analyzed for sensory attributes (colour, aroma, taste, and acceptability). Synbiotic RTD was also evaluated for stability over a period of 28 days at 4 °C. Synbiotic RTD developed an unpleasant flavor and aroma during the shelf life. Premix format of RTD developed using spray drying was reconstituted and found to be functionally and sensorially acceptable., Competing Interests: Compliance with ethical standardsWe declare that the work described is approved by all authors and the responsible authorities where the work was carried out.
- Published
- 2018
- Full Text
- View/download PDF
42. Modification of proteins and polysaccharides using dodecenyl succinic anhydride: Synthesis, properties and applications-A review.
- Author
-
Shah NN, Soni N, and Singhal RS
- Subjects
- Solvents, Surface Properties, Polysaccharides chemistry, Proteins chemistry, Succinic Anhydrides chemistry
- Abstract
Proteins and polysaccharides are among the biopolymers produced by living organisms for their structural integrity, protection, physiological functions, or as reserve energy. These biopolymers are extracted from their natural matrices by humans to fulfil basic as well as convenience needs. The inquisitive human nature, ever-growing demands and resources at disposal have led to copious research in the field of biopolymer modifications. The availability of reactive sites on these biopolymers make them suitable substrates for esterification, etherification, oxidation, epoxidation, N-acylation, alkylation, etc. Dodecenyl succinic anhydride (DDSA) is an esterifying agent that introduces a 12-carbon hydrophobic chain in the structure of the substrate containing suitable reactive sites. The use of DDSA as a modifying agent for biopolymers dates back to the mid-twentieth century. Even today, many biopolymers are explored for modification with DDSA for improved functionality. These modifications are aimed at catering the needs of the paint, pharmaceutical, cosmetic, food and textile industries. This review attempts to systematically compile reported research on the use of DDSA as a biopolymer modifying agent, the various reaction techniques, properties and applications thereof., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
43. Non-covalent conjugation of cutinase from Fusarium sp. ICT SAC1 with pectin for enhanced stability: Process minutiae, kinetics, thermodynamics and structural study.
- Author
-
Muley AB, Chaudhari SA, and Singhal RS
- Subjects
- Enzyme Stability, Hydrogen-Ion Concentration, Kinetics, Protein Structure, Secondary, Thermodynamics, Carboxylic Ester Hydrolases chemistry, Carboxylic Ester Hydrolases metabolism, Fusarium enzymology, Pectins metabolism
- Abstract
Cutinase, a member of α/β-fold hydrolase family possess potentially diverse applications in several industrial processes and products. The present work aims towards thermo-stabilization of cutinase from novel source Fusarium sp. ICT SAC1 via non-covalent interaction with polysaccharides. Although all six polysaccharides chosen for study enhanced the thermal stability, pectin was found to be most promising. The interaction protocol for cutinase with pectin was optimized sequentially with respect to the ratio of enzyme to pectin, solution pH, and buffer strength. Cutinase-pectin conjugate under optimized conditions (1:12, pH-6.5, 50mM) showed enhanced thermal stability as evident from lower inactivation rate constant, higher half-life and D-value within the 40-55°C. A slender rise in K
m and Vmax values and enhanced thermodynamic parameters of cutinase-pectin conjugate were observed after non-covalent interaction. Entropy values were 1.5-fold higher for cutinase-pectin conjugate at each temperature suggesting an upsurge in number of protein molecules in a transition activated state. Positive values of entropy for both forms of cutinase suggested a rise in disordered conformation. Noticeable conformational changes in cutinase after conjugation with pectin were confirmed by FTIR as well as fluorescence emission spectra. An increment in helix to turn conversion was observed in complexed cutinase vis-à-vis free cutinase., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
44. Isolation and Characterization of Acrylamidase from Arthrobacter sp. DBV1 and Its Ability to Biodegrade Acrylamide.
- Author
-
Bedade DK and Singhal RS
- Subjects
- Hydrogen-Ion Concentration, Acrylamide chemistry, Arthrobacter enzymology, Bacterial Proteins chemistry, Bacterial Proteins isolation & purification, Hydrolases chemistry, Hydrolases isolation & purification
- Abstract
Although acrylamide finds diverse industrial applications, its presence in the environment is hazardous due to its carcinogenic, neurotoxic, and teratogenic properties. In spite of the general toxicity of acrylamide in the monomer form, some microorganisms are able to use it as a source of energy by catabolizing it to ammonia and acrylic acid by means of acrylamidase (EC 3.5.1.4). The present work reports on a novel soil isolate as an acrylamide-degrading bacteria. Based on biochemical characterization and 16S ribosomal RNA (rRNA) gene sequence, the bacterial strain was identified as Gram-positive Arthrobacter sp. DBV1. The optimum growth conditions were found to be temperature (30 °C) and pH 6.0 to 7.0. Evaluation of the effect of concentration of acrylamide (10-50 mM) incorporated into minimal medium showed maximum growth of Arthrobacter sp. DBV1 at 30 mM acrylamide. The biodegradation of acrylamide was confirmed by HPLC analysis. Acrylamidase was isolated and characterized for temperature and pH optima, substrate specificity by using different amides, and the effect of different activators/inhibitors such as metal ions and amino acids. These finding suggests that the strain could be attractive for biodegradation of acrylamide from the environment and also possibly from foods containing preformed acrylamide.
- Published
- 2017
- Full Text
- View/download PDF
45. A strategic approach for direct recovery and stabilization of Fusarium sp. ICT SAC1 cutinase from solid state fermented broth by carrier free cross-linked enzyme aggregates.
- Author
-
Chaudhari SA and Singhal RS
- Subjects
- Ammonium Sulfate chemistry, Biocatalysis, Carboxylic Ester Hydrolases chemistry, Citrullus chemistry, Cross-Linking Reagents chemistry, Enzyme Stability, Enzymes, Immobilized chemistry, Industrial Waste, Kinetics, Lipase chemistry, Lipase metabolism, Protein Aggregates, Temperature, Carboxylic Ester Hydrolases isolation & purification, Fermentation, Fusarium enzymology
- Abstract
The major hurdles in commercial exploitation of cutinase (having both esterolytic and lipolytic activities) with potent industrial applications are its high production cost, operational instability and reusability. Although commercially available in immobilized form, its immobilization process (synthesis of support/carrier) makes it expensive. Herein we tried to address multiple issues of production cost, stability, and reusability, associated with cutinase. Waste watermelon rinds, an agroindustrial waste was considered as a cheap support for solid state fermentation (SSF) for cutinase production by newly isolated Fusarium sp. ICT SAC1. Subsequently, carrier free cross-linked enzyme aggregates of cutinase (cut-CLEA) directly from the SSF crude broth were developed. All the process variables affecting CLEA formation along with the different additives were evaluated. It was found that 50% (w/v) of ammonium sulphate, 125μmol of glutaraldehyde, cross-linking for 1h at 30°C and broth pH of 7.0, yielded 58.12% activity recovery. All other additives (hexane, butyric acid, sodium dodecyl sulphate, Trition-X 100, Tween-20, BSA) evaluated presented negative results to our hypothesis. Kinetics and morphology studies confirmed the diffusive nature of cut-CLEA and BSA cut-CLEA. Developed CLEA showed better thermal, solvent, detergent and storage stability, making it more elegant and efficient for industrial biocatalytic process., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
46. Biochemical Characterization of Extracellular Cellulase from Tuber maculatum Mycelium Produced Under Submerged Fermentation.
- Author
-
Bedade DK, Singhal RS, Turunen O, Deska J, and Shamekh S
- Subjects
- Ascomycota growth & development, Cellulase isolation & purification, Enzyme Activation, Enzyme Stability, Substrate Specificity, Ascomycota enzymology, Bioreactors microbiology, Cellulase chemistry, Cellulase metabolism, Cellulose chemistry, Extracellular Fluid enzymology
- Abstract
Interaction of truffle mycelium with the host plant involves the excretion of extracellular enzymes. The ability of Tuber maculatum mycelium to produce an extracellular cellulase during submerged fermentation was demonstrated for the first time. T. maculatum mycelia were isolated and tested for extracellular cellulase production at variable pH on solid agar medium, and the highest activity was observed at pH 7.0. Furthermore, T. maculatum was subjected to submerged fermentation in basal salt medium for cellulase production. Under optimized conditions using sodium carboxymethyl cellulose (0.5 % w/v) as carbon source and an initial pH of 7.0, the enzyme production yielded 1.70 U/mL of cellulase in the cell-free supernatant after 7 days of incubation time. The optimum of the obtained cellulase's activity was at pH 5.0 and a temperature of 50 °C. The enzyme showed good thermostability at 50 °C by retaining 99 % of its maximal activity over an incubation time of 100 min. The cellulase activity was inhibited by Fe
2+ and slightly activated by Mn2+ and Cu2+ at 1 mM concentration. The results indicated that truffle mycelium is utilizing cellulosic energy source in the root system, and the optimal conditions are those existing in the acidic Finnish soil.- Published
- 2017
- Full Text
- View/download PDF
47. Enhanced extraction of oleoresin from ginger (Zingiber officinale) rhizome powder using enzyme-assisted three phase partitioning.
- Author
-
Varakumar S, Umesh KV, and Singhal RS
- Subjects
- Catechols analysis, Fatty Alcohols analysis, Phytochemicals analysis, Powders analysis, Zingiber officinale chemistry, Plant Extracts analysis, Plant Preparations analysis, Rhizome chemistry
- Abstract
Ginger (Zingiber officinale R.) is a popular spice used worldwide. The oleoresin consists of gingerols, shogaols and other non-volatiles as chief bioactive constituents. Three phase partitioning (TPP), a bioseparation technique, based on partitioning of polar constituents, proteins, and hydrophobic constituents in three phases comprising of water, ammonium sulphate and t-butanol, was explored for extraction of oleoresin and gingerols from dry powder. Parameters optimized for maximum recovery of gingerols and [6]-shogaol were ammonium sulphate concentration, ratio of t-butanol to slurry, solid loading and pH. Ultrasound and enzymatic pretreatments increased the yield of oleoresin and its phytoconstituents. Ultrasound pretreatment showed separation of starch in the bottom aqueous phase but is an additional step in extraction. Enzymatic pretreatment using accellerase increased the yield of [6]-, [8]-, [10]-gingerols and [6]-shogaol by 64.10, 87.8, 62.78 and 32.0% within 4h and is recommended. The efficacy of the enzymatic pretreatment was confirmed by SEM and FTIR., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
48. Antioxidant Compounds in Traditional Indian Pickles May Prevent the Process-Induced Formation of Benzene.
- Author
-
Kharat MM, Adiani V, Variyar P, Sharma A, and Singhal RS
- Subjects
- Food Contamination analysis, Food Handling, Gas Chromatography-Mass Spectrometry, India, Antioxidants chemistry, Ascorbic Acid chemistry, Benzene analysis, Cucumis sativus chemistry, Food Additives chemistry
- Abstract
Pickles in the Indian market contain ascorbic acid from the raw material used and benzoate as an added preservative that are involved in the formation of benzene in soft drinks. In this work, 24 market pickle samples were surveyed for benzene content, as well as its precursors and other constituents that influence its formation. The analysis showed that pickle samples were high in acid content (low pH) and showed significant amount of ascorbic acid, minerals (Cu and Fe), and benzoic acid present in them. Also, most samples exhibited high antioxidant activity that might be attributed to the ingredients used, such as fruits and spices. The solid-phase microextraction headspace gas chromatography-mass spectrometry method was developed in-house for benzene analysis. Eleven of 24 samples had benzene, with the highest concentration of 4.36 ± 0.82 μg of benzene per kg of pickle for a lime pickle that was also reported to have highest benzoic acid and considerably less hydroxyl radical ((•)OH) scavenging activity. However, benzene levels for all 11 samples were considerably below the World Health Organization regulatory limit of 10 μg/kg for benzene in mineral water. Studies on model systems revealed that the high antioxidant activity of Indian pickles may have had a strong inhibitory effect on benzene formation.
- Published
- 2016
- Full Text
- View/download PDF
49. Identification of chondroitin-like molecules from biofilm isolates Exiguobacterium indicum A11 and Lysinibacillus sp. C13.
- Author
-
Bhotmange DU and Singhal RS
- Subjects
- Bacillaceae chemistry, Bacillaceae genetics, Bacillaceae isolation & purification, Biofilms, Chondroitin chemistry, DNA, Ribosomal genetics, Spectroscopy, Fourier Transform Infrared, Bacillaceae physiology, Chondroitin biosynthesis
- Abstract
Aims: The study aims to investigate whether the bacteria from biofilms can produce chondroitin-like molecules (CLMs)., Methods and Results: Chondroitin belongs to the class of glycosaminoglycans. Forty bacteria from biofilms were isolated and screened for the production of glycosaminoglycans. Two isolates A11 and C13 produced 43 and 26 mg l(-1) of chondroitinase AC II degradable glycosaminoglycans, respectively, suggesting the possibility of production of CLMs by them. These isolates were identified using 16S rDNA sequencing technique and fatty acid methyl ester analysis. These were recognized as Exiguobacterium indicum A11 (NCIM 5531) and Lysinibacillus sp. C13 (NCIM 5532) respectively. These strains were also characterized using polar lipid content and biochemical tests. The identity of the glycosaminoglycans produced was further confirmed using agarose gel electrophoresis, fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy., Conclusions: Prokaryotic biofilms were found to be a good source of bacteria synthesizing CLMs. Two wild strains producing significant amount of the same were identified and characterized., Significance and Impact of the Study: This is the first study exploring natural biofilms for the production of the therapeutic molecule, chondroitin/glycosaminoglycan. These isolates may be prospective new alternatives to recombinant strains that are reported for the production of chondroitin/glycoaminoglycan at an industrial scale. The production by these wild strains could be commercially attractive if the production is higher and/or can be improved further by strain improvement/process engineering. Further, these are new additions to the scientific literature on glycosaminoglycan-producing micro-organisms., (© 2015 The Society for Applied Microbiology.)
- Published
- 2015
- Full Text
- View/download PDF
50. Interaction of carbohydrates with alcohol dehydrogenase: Effect on enzyme activity.
- Author
-
Jadhav SB, Bankar SB, Granström T, Ojamo H, Singhal RS, and Survase SA
- Subjects
- Alcohol Dehydrogenase chemistry, Enzyme Inhibitors chemistry, Enzyme Inhibitors metabolism, Enzyme Inhibitors pharmacology, Glucose chemistry, Glucose pharmacology, Hydrogen-Ion Concentration, Kinetics, Oxidation-Reduction, Pectins chemistry, Pectins pharmacology, Protein Binding, Spectrometry, Fluorescence, Starch chemistry, Starch pharmacology, Sulfhydryl Compounds metabolism, Alcohol Dehydrogenase antagonists & inhibitors, Alcohol Dehydrogenase metabolism, Glucose metabolism, Pectins metabolism, Starch metabolism
- Abstract
Alcohol dehydrogenase was covalently conjugated with three different oxidized carbohydrates i.e., glucose, starch and pectin. All the carbohydrates inhibited the enzyme. The inhibition was studied with respect to the inhibition rate constant, involvement of thiol groups in the binding, and structural changes in the enzyme. The enzyme activity decreased to half of its original activity at the concentration of 2 mg/mL of pectin, 4 mg/mL of glucose and 10 mg/mL of starch within 10 min at pH 7. This study showed oxidized pectin to be a potent inhibitor of alcohol dehydrogenase followed by glucose and starch. Along with the aldehyde-amino group interaction, thiol groups were also involved in the binding between alcohol dehydrogenase and carbohydrates. The structural changes occurring on binding of alcohol dehydrogenase with oxidized carbohydrates was also confirmed by fluorescence spectrophotometry. Oxidized carbohydrates could thus be used as potential inhibitors of alcohol dehydrogenase., (Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.