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The main purpose of this study was to discover new tyrosinase inhibitory peptides from eel bone hydrolysates. After enzyme screening, alkaline protease was utilized, and optimal conditions were achieved through response surface optimization: solid-liquid ratio (1:25), time (5 h), and enzymolysis base ratio (3500 U/g). Inhibitory peptides of 1–3 kDa were isolated (IC50 = 2.162 mg/mL), and the inhibition was determined to be non-competitive and reversible. Subsequent LC-MS/MS and molecular docking revealed that the peptide with the lowest binding energy exhibited hydrogen bonding, hydrophobic interactions, and provided a potential explanation for the mechanism of inhibition by the peptides. [ABSTRACT FROM AUTHOR]

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The experiment was conducted to study the skin contact damage and stomach injury of direct feeding of alkaline protease. Guinea pigs were taken as animal models, the damage of the skin and stomach caused by alkaline protease were observed with alkaline protease at 0.02, 0.05, 0.10, 0.20 g/mL for skin contact 7 days, and 0, 1, 2, 5 g of alkaline protease were mixed into 100 g feed then fed to healthy guinea pigs for 3 days. The results showed that: ① the continuous contact of alkaline protease with skin 3 days, different concentration groups were caused obvious skin damage and scab, but the damage area (>40%) were not significantly different; when the contact days increased to 7 days, the damage area of 0.10, 0.20 g/mL concentration groups (>90%) were significantly higher than that of 0.02, 0.05 g/mL concentration groups (=79%). ② When the alkaline protease solution of 0.02, 0.10, 0.20 g/mL were continuously exposed to the skin for 2 days, the skin injury score increased significantly; when contact skin for 7 days, the score of each concentration group was > 3, reaching the degree of severe ulceration. ③ Healthy guinea pigs were fed with alkaline protease for 3 days, when the dosage was 1 g/100 g, the guinea pigs' stomach was damaged, but there was no death; when the dosage was 2 g/100 g, the stomach walls of guinea pigs were thinner and the folds were reduced, the mortality rate was 25%; when the dosage was 5 g/100 g, the stomach walls of guinea pigs were extremely thin and the mortality rate reached 75%. The results indicated that: 0.02-0.20 g/mL of alkaline protease enzyme liquid could cause serious damage when it was continuously exposed to the skin for 7 days; the addition of high dose of alkaline protease in the feed could cause stomach injury, and when the additive amount was > 2 g/100 g, it could cause animal death. [ABSTRACT FROM AUTHOR]

Alkaline proteases derived from haloalkaliphiles, extremophilic microorganisms thriving in high-pH and high-salt environments, have garnered significant attention in recent years due to their unique biochemical properties and versatile applications. This review highlights the isolation, characterization, and biotechnological potential of alkaline proteases produced by haloalkaliphilic microorganisms. Haloalkaliphiles, found in soda lakes, saline-sodic soils, and other extreme habitats, have evolved to adapt and thrive under conditions characterized by elevated alkalinity and salinity. Alkaline proteases from these microorganisms exhibit high stability and activity under extreme pH and salinity, making them valuable candidates for various industrial processes. The review provides insights into the biochemical properties of alkaline proteases, including optimal pH, temperature, stability, and substrate specificity. Molecular studies have revealed unique structural features that contribute to the stability of these enzymes under harsh conditions, shedding light on their potential applications in challenging industrial processes. The industrial applications of alkaline proteases from haloalkaliphiles are diverse and encompass several sectors. Their role as powerful biocatalysts in detergent formulations is well-established, where they effectively break down proteinaceous stains under high pH conditions. Additionally, these enzymes find applications in leather processing, food industry, waste treatment, and pharmaceuticals, owing to their ability to operate efficiently in alkaline and saline environments. Their stability under extreme conditions, coupled with advances in biotechnological approaches, positions these enzymes as crucial components in the development of sustainable and efficient processes across various industries. Continued research in this field holds promise for discovering novel enzymes and unlocking their full potential for biotechnological innovation. [ABSTRACT FROM AUTHOR]

This study was designed to explore the hepatoprotective effects of enzymatic degradation products derived from sturgeon roe on alcohol-damaged hepatocytes and to elucidate the underlying mechanisms. Utilizing sturgeon roe as the research material, the enzymatic process was optimized by focusing on key parameters such as enzymatic efficiency and in vitro activity. The protective effects on hepatocytes were systematically investigated by using the HepG2 cell model. Advanced computerized virtual screening technology was employed to identify potential bioactive peptides within the sturgeon roe. The findings indicated that the optimum enzymatic product of sturgeon roe was obtained under the conditions of 1:1 compounding of alkaline protease (1343 U/g) and trypsin (27 U/g) for 8 h, yielded a protein recovery of 49.30%±0.57%, a hydrolysis degree of 46.05%±0.92%, and ABTS+ free radical scavenging rate of 51.45%±0.66%. Notably, at a concentration of 5 mg/mL, this product significantly enhanced the activity of alcohol dehydrogenase (ADH) by 168.64%±1.42% (P<0.05). The product prepared under this enzymatic condition at 0.3~2 mg/mL significantly elevated superoxide dismutase (SOD) activity, glutathione (GSH) contents, and reduced malondialdehyde (MDA) contents in alcohol-injured HepG2 cells compared to the model group (P<0.05). In addition, the product at 0.3~2 mg/mL also significantly reduced alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities (P<0.05). Virtual screening identified 5 peptides, including LPG and FLPR, in the sturgeon roe enzymatic degradation product, showed promising hepatoprotective properties against alcohol-induced hepatocyte injury. Consequently, this study lays a solid foundation for the further development and utilization of aquatic resources, such as sturgeon roe, in hepatoprotective applications. [ABSTRACT FROM AUTHOR]

Objective: To obtain the optimal enzyme and preparation process for Schisandra chinensis protein peptides and investigate its in vitro antioxidant activity. Methods: Seven proteases were used to hydrolyze Schisandra chinensis protein. Based on the degree of hydrolysis, free radical scavenging activity, polypeptide yield and content of different hydrolysates of Schisandra chinensis protein and the comprehensive evaluation of molecular weight in SDS-PAGE, the optimal protease was screened. The DPPH free radical scavenging rate was used as the index, and the optimal enzymatic hydrolysis process was determined by single factor test combined with response surface analysis. The scavenging ability of O2-*, *OH, DPPH*, ABTS+*, Fe2+ chelating ability and Fe3+ reducing ability of Schisandrae chinensis protein peptides were analyzed and compared with Schisandra chinensis protein. Results: The optimum enzyme for the preparation of Schisandra chinensis protein peptides was alkaline protease. The optimum enzymatic hydrolysis parameters were as follows: substrate concentration 5%, enzyme-to-substrate ratio 1%, enzymatic hydrolysis time 3 h, enzymatic hydrolysis temperature 55 °C, pH9.0. Under these conditions, the polypeptide content was 88.61%, the degree of hydrolysis was 24.21%, and the DPPH* scavenging rate was 86.96%. The free radical scavenging ability and reducing ability of Schisandrae chinensis protein peptides were better than those of Schisandrae chinensis protein. Conclusion: This study determined the optimum enzyme and hydrolysis process of Schisandrae chinensis protein peptides, and pointed out that Schisandrae chinensis protein peptides had better antioxidant activity in vitro and could be used as a natural antioxidant. [ABSTRACT FROM AUTHOR]

Summary: The combined effects of gelatin extraction methods and protease types on the functional properties of tilapia scale gelatin hydrolysates (TSGH) were investigated. The tilapia scale gelatin (TSG) was extracted after acid/base pretreatments, respectively, and then hydrolysed with different proteases to produce TSGHs. The degree of hydrolysis and the content of trichloroacetic acid soluble peptide were increased with hydrolysis time, while the content of β‐sheet was decreased significantly with the hydrolysis time (P < 0.05). The emulsification stability of acid protease hydrolysate (APH) was higher than that of neutral protease hydrolysate (NPH) and alkaline protease hydrolysate (ALPH). All samples showed good resistance to oxidation: DPPH (20%–64.66%), ABTS (29.08%–63.04%), and iron reducing power (0.017–0.499). The hydrolysates obtained from the base‐pretreated TSG showed higher antioxidant properties than acid‐pretreated TSG. The antioxidants of different protease hydrolysates are ranked by ALPH > NPH > APH. In conclusion, gelatin extraction methods and its hydrolysis conditions had influences on the functional properties of TSGH, and the study of the processing of marine biological wastes is of great significance in realising their high‐value utilisation and reducing the burden on the environment. [ABSTRACT FROM AUTHOR]

Background and Objectives: Wheat gluten is a high‐quality, low‐priced, and nutritious plant protein. Applications of wheat gluten protein could be expanded by improving its solubility through enzymatic modifications. Herein, we investigated the effect of proteolytic processing on the physicochemical properties of wheat gluten protein. Findings: The degree of hydrolysis, trichloroacetic acid‐soluble nitrogen (TCA‐SN), and peptidyl nitrogen content of the enzymatic digestion products increased, and the TCA‐SN content exceeded 60% in all cases. The ζ‐potentials of all products after enzymatic digestion were significantly decreased and were negative. Three enzymatic solutions increased the stability of the solution system and the surface hydrophobicity of the enzymatic products to different degrees. The products after enzymatic digestion by alkaline protease had better antioxidant capacity. Conclusions: This study provides theoretical support for expanding the applications for wheat protein to achieve the added value of wheat products and enhance the utilization rate of these readily available raw materials. Significance and Novelty: This study investigates the dual enzyme stepwise enzymatic hydrolysis of wheat gluten protein by alkaline protease and neutral protease, which increases the water‐soluble protein content of wheat gluten protein. The resulting hydrolysate has a high peptide nitrogen content. [ABSTRACT FROM AUTHOR]

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Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hemp seed protein (HSP), a by-product of hemp oil processing, was converted into a functional protein ingredient enriched with γ-aminobutyric acid (GABA) and peptides through a two-step microbial fermentation process. To enhance peptide and free amino acid production from HSP, it was hydrolyzed using alkaline protease produced by Bacillus subtilis HA. The HSP was hydrolyzed at a degree of 40% at 55 °C for 24 h, yielding a pH of 6.55, an acidity of 1.22%, and 205.45 mg% tyrosine equivalents. This process resulted in the production of low molecular-weight peptides. (<5000 Da) The total amino acid content and branched-chain amino acids (leucine, isoleucine, and valine) were 6.78 mg/g and 1.47 mg/g. Subsequently, the production of γ-aminobutyric acid (GABA) in the HSP hydrolysate was optimized through co-fermentation with lactic acid bacteria in the presence of 5% MSG at 30 °C for 5 days. The serial co-fermented HSP hydrolysate exhibited a GABA content of 33.98 mg/g and a viable bacterial count of 9.51 log CFU/mL for Lb. plantarum KS2020. This serial co-fermentation process, combining proteolysis and lactic acid fermentation, not only increased the peptide content but also promoted GABA accumulation, positioning HSP hydrolysate as a promising candidate for functional foods with potential health benefits. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Considering the current growing interest in new and improved enzymes for use in a variety of applications, the present study aimed to characterize a novel detergent-stable serine alkaline protease from the extremophilic actinobacterium Microbacterium metallidurans TL13 (MmSP) using a combined in silico and experimental approach. The MmSP showed a close phylogenetic relationship with high molecular weight S8 peptidases of Microbacterium species. Moreover, its physical and chemical parameters computed using Expasy's ProtParam tool revealed that MmSP is hydrophilic, halophilic and thermo-alkali stable. 3D structure modelling and functional prediction of TL13 serine protease resulted in the detection of five characteristic domains: [catalytic subtilase domain, fibronectin (Fn) type-III domain, peptidase inhibitor I9, protease-associated (PA) domain and bacterial Ig-like domain (group 3)], as well as the three amino acid residues [aspartate (D182), histidine (H272) and serine (S604)] in the catalytic subtilase domain. The extremophilic strain TL13 was tested for protease production using agricultural wastes/by-products as carbon substrates. Maximum enzyme activity (390 U/gds) was obtained at 8th day fermentation on potato peel medium. Extracellular extract was concentrated and partially purified using ammonium sulfate precipitation methodology (1.58 folds purification fold). The optimal pH, temperature and salinity of MmSP were 9, 60 °C and 1 M NaCl, respectively. The MmSP protease showed broad pH stability, thermal stability, salt tolerance and detergent compatibility. In order to achieve the maximum stain removal efficacy by the TL 13 serine protease, the operation conditions were optimized using a Box–Behnken Design (BBD) with four variables, namely, time (15–75 min), temperature (30–60 °C), MmSP enzyme concentration (5–10 U/mL) and pH (7–11). The maximum stain removal yield (95 ± 4%) obtained under the optimal enzymatic operation conditions (treatment with 7.5 U/mL of MmSP during 30 min at 32 °C and pH9) was in good agreement with the value predicted by the regression model (98 ± %), which prove the validity of the fitted model. In conclusion, MmSP appears to be a good candidate for industrial applications, particularly in laundry detergent formulations, due to its high hydrophilicity, alkali-halo-stability, detergent compatibility and stain removal efficiency. [ABSTRACT FROM AUTHOR]

In this study, the mucosa of porcine small intestine was used as the raw material to optimize the optimal process for the extraction of heparin (Hep) by high hydrostatic pressure enzymatic hydrolysis by response surface test, to study the adsorption conditions of Hep purified by macroporous resin, and to explore the stability of Hep (pH, temperature, and light). The results showed that the optimal enzymatic process was alkaline protease, 3.1 h, 55 °C, pH9.5, pressure 100 MPa, enzyme addition 9%, salt concentration 2.0%, the actual average concentration of Hep was measured to be 11.56± 0.12 U/mL. The purification of Hep was carried out by using the D958 resin, with the up-sampling flow rate of 1.5 BV/h, the concentration of the eluent of 4 mol/L NaCl, and the elution flow rate of 1.5 BV/h, the purity of Hep could reach 68.75% after purification, and the electrophoretic purity achieved. In the stability study, Hep had the best stability at pH7.5, better stability at 40 °C, and light had no effect on the stability of Hep. This study can greatly improve the extraction effect of Hep and provide theoretical and technical support for the high value processing and utilization of pig small intestine. [ABSTRACT FROM AUTHOR]

Protease is used in various industries and the uprising demand urges for its enhanced production. Herein, strain improvement by mutagenic treatment with ethyl methanesulfonate and ultra-violet light was carried out in proteolytic Bacillus subtilis AKAL7. Mutants were screened through proteolytic clear zone ratio on the skim milk agar. The highest protease producer mutant E29 was selected for enhanced protease production in shake flask fermentation using one-factor-at-a-time (OFAT) and statistical methodology. The OFAT approach resulted in maximum level of protease (161.7 U/mL) after 24 h of fermentation at 30 °C, pH 10 in a basal medium. The statistical Plackett–Burman design predicted peptone, yeast extract, MgSO4, pH, and temperature as the significant factors among eight independent variables for the protease production. The response surface methodology (RSM) determined the optimal concentration of the significant factors for maximum protease production (741.284 U/mL). The experimental protease level (722.7 U/mL), which was ~5-fold of that produced with the basal media, validated the predicted values of RSM. The partial purification resulted in a final ~14-fold purified protease with specific activity of ~9508 U/mg protein and molecular weight ~40 kDa. The protease showed maximum activity at 50 °C and stability up to 45 °C for 1 h. However, 10 mM CaCl2 increased its thermostability. Severe inhibition of protease activity by phenylmethylsulfonyl fluoride and HgCl2 revealed the partially purified protease as serine and cysteine type, which was active at pH 7.0–12.0 with the optima at pH 10.0. The protease could substantially dehair the cow skin within 14 h of treatment and retain 98% activity after 30 days of lyophilization. [ABSTRACT FROM AUTHOR]

This study investigated the effect of enzymatic treatment on the allergenicity of α‐lactalbumin (ALA). Utilising the BIOPEP database, we identified five proteases that optimally clear allergen epitopes, while considering cost‐efficiency. Notably, alkaline protease demonstrated the highest antigen reduction rate of 46.46%, with a hydrolysis degree of 30.01%, and 87.80% of the resulting peptides were found to be smaller than 1 kDa. Peptidomics analysis revealed AA32–38 and AA42–48 as key linear epitopes of ALA. Furthermore, alkaline protease treatment significantly reduced the proportion of hydrophilic amino acids, thereby decreasing the allergen potential of ALA by lowering its IgE/IgG binding affinity. [ABSTRACT FROM AUTHOR]

The effect of four enzyme preparations (EP), Bacillolysin, Agroprot, Protozyme, and Protozyme C (Russia), on the protein and peptide profiles of the protein isolate isolated from peas of the Focor variety, as well as on its smell and taste, was investigated in this work. It was shown that enzyme treatment can improve the odor characteristics of the isolate. Thus, it was possible to reduce significantly the severity of the bean and herbal smell. At the same time, enzyme treatment also improved the taste of the isolate: it was possible to reduce significantly the severity of disturbing flavors such as leguminous, astringent, bitter, and herbal. The results obtained allowed us to select EP (fungal acid aspartic protease) to improve the organoleptic parameters of pea protein isolates intended for the production of meat and dairy product analogs. [ABSTRACT FROM AUTHOR]

The article explores the screening, isolation and production of alkaline protease from various agro-industrial wastes by using taguchi experimental design. The study discusses the application of alkaline proteases, cost of enzyme as a factor affecting the use of alkaline proteases, sources of protease production, generation and composition of agro-industrial wastes, sources of agro-industrial by-products, alkaline protease sources and production, and the inability of plant and animal proteases.

The present work aimed to examine the association between the changes in the surface hydrophobicity and surface activity of soybean protein isolate (SPI) following structural alterations. To this end, the effects of heating, pH modification, ultrasonication, surfactant (SDS, sodium dodecyl sulphate) treatment, alkaline protease hydrolysis, peracetic acid treatment, and acylation on the surface activity and surface hydrophobicity of SPI were investigated. The results demonstrated that the changes in the surface hydrophobicity of SPI could accurately reflect the changes in its surface activity. A strong correlation between surface hydrophobicity and surface activity alterations was noted after the SPI molecules underwent structural modifications. The higher the surface hydrophobicity of the treated SPI, the greater its surface activity. Given that the surface hydrophobicity of SPI reflects the actual distribution of hydrophobic residues on its surface, this parameter can serve as a key indicator for evaluating and predicting changes in the surface activity of SPI. [ABSTRACT FROM AUTHOR]

The solidification technology of natural rubber exerts a significant impact on the properties of natural rubber. The solidification technology of alkaline protease has been highly valued by researchers at home and abroad because of its good solidification effect, excellent vulcanization performance, and low pollution. In this study, the effects of alkaline protease solidification technology and enzyme dosage on the structure and properties of natural rubber were investigated and compared with those of formic acid solidification technology. The solid‐state NMR results showed that increasing the enzyme dosage increased the molecular chain entanglements in the raw rubber. The gel content test results showed that the natural network structures (i.e. gels) increased after the addition of alkaline protease. The test results of the vulcanization characteristics showed that the addition of alkaline protease significantly shortened the positive vulcanization time. The Mw was the largest at an enzyme dosage of 0.07%. The test results for mechanical properties showed that the mechanical properties were best when the enzyme dosage was 0.07%. In addition, as the alkaline protease dosage increased, the Akron abrasion volume of natural rubber decreased, and the Akron abrasion volume was the lowest at an enzyme dosage of 0.07%. [ABSTRACT FROM AUTHOR]

In this paper, alkali protease was used to enzymatically hydrolyze wheat germ proteins grown in the Hetao region. A univariate analysis and an orthogonal experiment were conducted to optimize the enzymatically hydrolyze process conditions of wheat germ proteins, with the degree of hydrolysis taken as the indicator. Moreover, the in vitro hypolipidemic effect of wheat germ polypeptides was investigated. The results showed that the degree of hydrolysis of wheat germ proteins was 37.18%±0.25% achieved by the following conditions, substrate concentration of 6.0%, temperature at 50 ℃, pH of 10.5 and protease amount of 12000 U/g. When the concentration of wheat germ polypeptides was 5 mg/mL, the rate of inhibiting cholesterol solubilisation into micelles was 27.11%±0.36%, the pancreatic lipase activity inhibition rate was 33.54%±0.57%, and cholesterol esterase activity inhibition rate was 38.13%±0.29%. Moreover, after ultrafiltration, the relative molecule weight of polypeptides less than 1 kDa accounted for 54.30%±0.32% of all polypeptides, indicating that low-molecular-weight wheat germ polypeptides might yield superior hypolipidemic effects. The work provides a theoretical foundation for further exploring the mechanism between Hetao wheat germ polypeptides and hypolipidemic effect.

The degummed wastewater from silk processing contains a huge amount of amino acids and polypeptides from sericin. The silk degumming water is far from being exploited fully. Sericin in the degumming water is generally wasted and causes environmental pollution. In this study, simulated silk degumming water was hydrolyzed by alkaline protease to produce abundant amino acids and polypeptides. After enzymatic hydrolysis, the maximum free amino groups concentration in the silk degumming water was approximately 54 mM. It facilitated the recycling of silk degumming water for the production of melanin-like amino acid surfactants as raw materials. 4-Tert-butylcatechol was used as the starting material to generate o-quinone via oxidation by ceric ammonium nitrate. o-Quinone was coupled with free amino groups in enzymatic hydrolysates of silk degumming water to synthesize a sericin-based amino acid surfactant as hydrophobic and hydrophilic group, respectively. Through the green and simple synthesis route, the product was characterized to have a novel melanin-like structure. The product exhibited superior surface-active properties by lowering the surface tension to 32.39 mN m−1. Furthermore, it demonstrated good foaming ability and foam stability, with the initial foam volume of 37 mL and the foam half-life time of more than 25 min. The product owned a good emulsification ability in the oil-water emulsion with delamination time of 297 s and 291 s for emulsion formed by soybean oil and liquid paraffin, respectively. The wetting time of the canvas sheet was only 134 s. Consequently, the product showed low surface tension, good foaming, emulsifying, and wetting properties. • Utilization of silk degumming water as renewable source for amino acid surfactants. • Novel structure similar with melanin by coupling amino acid to o-quinone. • Simultaneous treatment of silk degumming water. • Green route composed of only easy oxidation and spontaneous coupling reaction. • Production of surfactants with superior foaming, emulsifying, and wetting capacity. [ABSTRACT FROM AUTHOR]

为促进花生蛋白的深加工和更广泛的应用，采用高静压联合碱性蛋白酶酶法改性花生蛋白。通过单因素试验考察了静压力、pH、酶添加量、酶解时间和酶解温度对花生蛋白溶解度的影响，在此基础上，采用正交试验优化花生蛋白联合改性工艺条件，并测定了联合改性花生蛋白的起泡性和泡沫稳定性、巯基和二硫键含量以及总还原能力。结果表明：花生蛋白联合改性最佳工艺条件为静压力300 MPa、1 g/100 mL碱性蛋白酶（20万U/g）添加量3.0 mL（100 mL质量分数5%的花生蛋白溶液）、酶解时间60 min、pH 10、酶解温度50 ℃，在此条件下联合改性花生蛋白溶解度为（82.87±0.51）%；联合改性花生蛋白的起泡性、泡沫稳定性、巯基含量、总还原能力显著提高，二硫键含量显著下降。综上，高静压联合酶法改性改善了花生蛋白的理化性质及功能特性，有利于其深加工及更广泛的应用。In order to promote the deep processing and broader application of peanut protein, peanut protein was modified by high hydrostatic pressure combined with alkaline protease hydrolysis. The effects of hydrostatic pressure, pH, enzyme addition amount, enzymatic time and enzymatic temperature on the solubility of peanut protein were investigated by single factor experiment, then orthogonal experiment was used to optimize the modification process of peanut protein. The foaming property and foam stability, sulfhydryl and disulfide bond contents, and total reducing capacity of the co-modified peanut protein were determined. The results showed that the optimal co-modification conditions for peanut protein were hydrostatic pressure 300 MPa, 1 g/100 mL alkaline protease(200 000 U/g) addition amount 3.0 mL (based on 100 mL peanut protein solution with mass fraction of 5%), pH 10, enzymatic temperature 50 ℃, and enzymatic time 60 min, and the protein solubility was (82.87±0.51)% under these conditions. The foaming property and foam stability, sulfhydryl group content, and total reducing capacity of co-modified peanut protein improved, while the disulfide bond content decreased. In conclusion, the combination of high hydrostatic pressure and enzymatic method can improve the physicochemical properties and functional properties of peanut protein, which facilitates the deep processing and broader application of peanut protein.

Objective: To investigate the technological conditions and antioxidant properties of Asini Corii Colla (ACC) peptides prepared by enzymolysis. Methods: The enzymatic hydrolysis conditions of ACC protein peptide prepared by Alcalase 2.4L were optimized using ACC as raw material. On the basis of single factor experiments, orthogonal test was carried out to determine the optimum process conditions with pH, enzyme-substrate ratio and enzymolysis temperature as the factors and the degree of hydrolysis (DH) of ACC as the indexes. To comprehensively analyze the enzymatic hydrolysis effect, the molecular weight distribution of ACC solution before and after enzymatic hydrolysis was determined by high performance gel chromatography, and the antioxidant activity of ACC solution before and after enzymatic hydrolysis was investigated by detecting scavenging rates of ABTS+ and DPPH free radicals. Four kinds of ultrafiltration membranes with different pore sizes were used to separate the ACC peptide solution, and the antioxidant activity of ACC peptide with different molecular weight was studied. Results: The optimum enzymolysis conditions were pH10.5, enzyme-substrate ratio 9% and enzymolysis temperature 63 ℃. Under these conditions, the DH was 15.93%. After enzymatic hydrolysis, the molecular weight of ACC solution was mostly below 5000 Da. When the concentration was 10 mg/mL, the ABTS+ free radical scavenging rate of the ACC peptide solutions before and after enzymolysis were 75.83%±0.32% and 93.16%±0.21%, respectively. The ability of scavenging DPPH free radicals was 16.93%±2.41% and 39.95%±1.27%. Five groups of ACC peptides with different molecular weight (>30 kDa, 10~30 kDa, 3~10 kDa, 1~3 kDa and

BACKGROUND RESULTS CONCLUSION Aspergillus oryzae protease can release the opioid peptide β‐casomorphin‐10 (CM‐10, YPFPGPIPNS, 60–69) from A2‐type casein. However, not only is the yield of the active peptide low, but the key enzyme involved in processing has yet to be identified.A significant amount of the opioid peptide 60YPFPGPIPNSLP71 (CM‐12) was produced from the A2‐type casein peptide 53AQTQSLVYPFPGPIPNSLPQNIPPLTQTPV82 when the active protease in A. oryzae protease extract was fractionated with DEAE‐Sepharose. The fractionated enzyme produced CM‐12 from bovine A2‐type casein but not from bovine A1 casein. A major protein of 34 kDa was purified and identified as an alkaline protease (Alp). Motif prediction of the Alp cleavage site using Multiple EM for Motif Elicitation analysis revealed preferable cleavage at the C‐terminal end of Ser–Leu–Xaa for the release of CM‐12. A2‐type casein hydrolysate by Alp exhibited similar levels of opioid activity to that of synthetic CM‐12 in cAMP‐Glo assays with μ‐opioid receptor‐expressing HEK293 cells. These results suggest that CM‐12 is a major opioid peptide in the casein hydrolysate.Our findings showed that Alp fractionated from A. oryzae protease extract produced the opioid peptide CM‐12 from A2‐type casein as a result of preferential cleavage at the C‐terminal end of Ser–Leu–Xaa and the removal of coexisting enzymes. Moreover, docking predictions suggested a stable interaction between CM‐12 and the 3D structure of Alp. Casein hydrolysate with Alp‐containing CM‐12 has the potential for use as a bioactive peptide material with opioid activity. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The objective of this work is to study the effect of applying simultaneous ultrasonication and alkaline protease treatment to the wet‐milling of high‐amylose corn on improving the starch yield and reducing the starch protein content. After applying the optimal conditions of simultaneous ultrasonication and protease treatment to the wet milling, the starch yield is elevated to 61.3% and the starch protein content is decreased to 0.44% when compared to the conventional process (48.9% and 1.75%, respectively). High‐amylose corn starch extracted using simultaneous ultrasonication and protease treatment has crystalline structure, relative crystallinity, pasting properties, thermal properties, and enzymatic digestibility similar to the one extracted from the conventional process. The results suggest that simultaneous ultrasonication and protease treatment are a friendly approach in improving the yield of high‐amylose corn starch and reducing the starch protein content, causing no obvious change in starch physicochemical properties and enzymatic digestibility. This study provides useful information for scaling up simultaneous ultrasonication and protease treatment to industrial scale with minor modifications of the conventional wet‐milling process. [ABSTRACT FROM AUTHOR]

BACKGROUND: The present study was conducted to investigate the effects of dietary novel alkaline protease from Bacillus licheniformis on the growth performance, meat quality, antioxidant status and intestinal morphology of broilers. In total, 4000 broilers were randomly assigned into five groups and treated with normal control, normal control + 100 mg kg−1 protease, normal control + 200 mg kg−1 protease, normal control + 300 mg kg−1 protease and normal control + 400 mg kg−1 protease. RESULTS: Supplementing protease impacted final body weight (linear, P = 0.003; quadratic, P = 0.006) and decreased feed conversion rate (linear, P = 0.036) in broilers. Moreover, dietary protease significantly increased breast muscle rate (linear, P = 0.005; quadratic, P = 0.021) and decreased drip loss (linear, P < 0.001; quadratic, P < 0.001). In addition, dietary protease notably increased protein digestibility (linear, P = 0.001; quadratic, P = 0.006) and trypsin activity (linear, P = 0.002; quadratic, P = 0.009) in jejunum. Light microscopy revealed that the jejunum villi in the 300 mg kg−1 and 400 mg kg−1 groups exhibited greater height and a denser arrangement compared to those in the control group. The addition of protease decreased malondialdehyde content (linear, P < 0.001; quadratic, P < 0.001) and increased total antioxidant capacity (linear, P = 0.001; quadratic, P < 0.001) in pectoral muscles. CONCLUSION: The results of the present study suggest that dietary novel alkaline protease from B. licheniformis improved growth performance by affecting trypsin activity, protein digestibility, antioxidant capacity and intestinal health. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A novel alkaline serine protease, derived from the Staphylococcus aureus strain ALA1 previously isolated from dromedary milk, was subjected to purification and characterization. Optimal protease production occurred under specific culture conditions. The purified protease, designated S. aureus Pr with a molecular mass of 23,662 Da and an N-terminal sequence, showed an approximately 89% similar identity with those of other Staphylococcus strains. It exhibited its highest enzymatic activity at a pH of 10.0 and 60 °C in the presence of 3 mM Ca2+. Remarkable thermostability was observed at temperatures up to 70 °C and within a pH range of 6.0 to 10.0 for 2 h. The presence of Ca2+ or Mg2+ and Zn2+ significantly enhanced both enzymatic activity and thermal stability. Additionally, notable stability was demonstrated in the presence of reducing and chaotropic agents as well as in surfactants, oxidizing agents, and organic solvents commonly found in detergent compositions. This highlights the enzyme's potential as a versatile biocatalyst, especially in detergents. Its stability and compatibility with laundry detergents matched Alcalase 2.5 L, type Dx, and the Stearothermophilus protease, used as controls. Collectively, this study investigated the potential utilization of S. aureus Pr in industrial detergents as an excellent candidate for incorporation as an additive in detergent formulations. [ABSTRACT FROM AUTHOR]

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Due to the growing need for alkaline proteases in various industrial applications, the preference for microbial sources, such as bacteria and fungi, has surged in comparison to plant and animal-derived alternatives. These microorganisms which can be isolated from natural alkaline habitats have emerged as promising candidates for large-scale industrial production. To meet this demand, greater attention is being given to improving the enzyme yields by optimizing culture conditions employing various approaches, viz., optimization of environmental and nutritional factors, statistical methodologies for screening, strain improvement, etc. Although acidic and neutral proteases are currently in industrial use, this review focuses on alkaline proteases from various sources because of their catalytic abilities at extreme pH values. While acidic proteases do possess distinctive and valuable catalytic capabilities at extreme pH values, they are predominantly utilized in the food industry for specific applications and are primarily produced by fungi, in contrast to alkaline proteases. Considering this, the present review focuses extensively on various environmental and nutritional factors affecting alkaline protease production in submerged fermentation. Additionally, the purification methodologies adopted, and properties of alkaline proteases obtained from different sources are discussed, and the industrial applications of alkaline proteases are also highlighted. [ABSTRACT FROM AUTHOR]

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study evaluated Streptomyces rochei strain NAM-19 solid-state fermentation of agricultural wastes to produce alkaline protease. Alkaline protease production increased with flaxseed, rice bran, and cheese whey fermentation reaching 147 U/mL at 48 h. Statistical optimization of alkaline protease production was performed using the central composite design (CDD). Results of CDD and the optimization plot showed that 4.59 g/L flaxseed, 4.31 g/L rice bran, 4.17 mL cheese whey, and a vegetative inoculum size of 7.0% increased alkaline protease production by 27.2% reaching 186 U/mL. Using the 20–70% ammonium sulfate fractionation method, the optimally produced enzyme was partially purified to fivefold. The partially purified alkaline protease was then covalently immobilized on a biopolymer carrier, glutaraldehyde-polyethylene-imine-κ-carrageenan (GA-PEI-Carr), with 90% immobilization efficiency. Characterizations revealed that immobilization improved thermostability, reusability, optimum temperature, and sensitivity towards metal ions of the free enzyme. The optimal temperature for free and immobilized enzymes was 40 and 50 °C, respectively. Both enzymes had the same optimum pH of 10. Immobilization increased Km from 19.73 to 26.52 mM and Vmax from 56.7 to 62.5 mmol min−1L−1. The immobilized enzyme retained 35% of its initial activity at 70 °C, while the free enzyme retained only 5%. The immobilized enzyme kept 80% of its initial activity at the 20th cycle. After 7 weeks of storage, the free enzyme lost all its initial activity, whereas the immobilized enzyme retained 50%. The free and immobilized enzymes were able to hydrolyze gelatin, and azo-casein demonstrating different relative activity, 85, 80, 90 and 95%, respectively, compared to casein (100%). [ABSTRACT FROM AUTHOR]

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Methods: Therefore, in this study, we assessed the changes in growth, morphology, digestive enzymes, and hormone levels in T. modestus from 0--60 days post-hatching (dph) and revealed growth turning points by morphological measurement and determination of digestive enzyme activities and hormone levels. We found that ontogenesis could be divided into the larval (0--20 dph) and juvenile (20--60 dph) stages. Acid and alkaline protease activity significantly increased and decreased, respectively, from 12-- 25 dph, likely due to the development of stomach and gastric glands. Acid phosphatase levels significantly increased at 0 and 4 dph, whichmay be related to the regulation of metabolism and immune protection. A sharp increase in alkaline phosphatase levels at 20 and 25 dph was observed and was likely due to the development of the brush border membrane of enterocytes. The amylase level was significantly higher at 25, 30, and 35 dph, possibly due to better digestion and absorption during the transition from consuming Artemia to compound feed. In newly hatched larvae, the level of thyroid hormones triiodothyronine (T3) and thyroxine (T4) gradually increased and peaked at 35 dph, highlighting the importance of these hormones during the development of T. modestus. Growth hormone (GH) levels first increased from 0--8 dph, with a plateau at 8--20 dph, and then increased at 25--30--35 dph. For insulinlike growth factor 1 (IGF-1), a significant increase with a subsequent plateau was observed between 8 and 20 dph, followed by a substantial decrease between 30 and 35 dph. These results suggest that the regulating functions of GH and IGF-1 are synchronised. Digestive enzyme activity and hormone levels of abnormal fry at 30 dph were lower than those of normal fish, highlighting the importance of specific hormones, especially T4 and IGF-1, in the development of T. modestus. [ABSTRACT FROM AUTHOR]

The spotted seatrout (Cynoscion nebulosus)—an important commercial species—has a high potential for aquaculture in the Gulf of Mexico. To optimize its feeding during larval rearing, this study aims to evaluate the primary gastric (pepsin), intestinal (leucine aminopeptidase and alkaline phosphatase), and pancreatic (alkaline protease, trypsin, chymotrypsin, amylase, and lipase) enzyme activities from hatching to day 30. A multivariate analysis identified three digestive enzyme development stages during the spotted seatrout larval transformation. The first stage occurred between 1 (mean ± standard error (SE) = 1.73 ± 0.14 millimeter (mm) standard length (SL)) and 3 (2.14 ± 0.07 mm SL) days after hatching (DAH); a period of digestive stability showed the highest activity in amylase and bile salt-dependent lipase. The second stage (from 4 (2.53 ± 0.09 mm SL) to 20 (10.92 ± 0.51 mm SL) DAH) was a period of digestive transition, during which leucine aminopeptidase, chymotrypsin, and alkaline proteases were identified as the predominant enzymes from 4 to 5 DAH. In the third stage—a period of digestive stability—pepsin was the major enzyme that occurred between 25 (16.51 ± 0.81 mm SL) and 30 (25.91 ± 0.82 mm SL) DAH. These results indicate that the spotted seatrout larvae have a digestive system adapted to lipids and carbohydrates at the onset of feeding, with an immediate transition to protein digestion when exogenous feeding begins. Additionally, the digestive system of the spotted seatrout may be considered mature at 25 DAH. Further research is needed to elucidate the mechanisms of digestive tract development in the spotted seatrout larvae. [ABSTRACT FROM AUTHOR]

Peptides possessing antihypertensive attributes via inhibiting the angiotensin-converting enzyme (ACE) were derived through the enzymatic degradation of Trichiurus lepturus (ribbonfish) using alkaline protease. The resulting mixture underwent filtration using centrifugation, ultrafiltration tubes, and Sephadex G-25 gels. Peptides exhibiting ACE-inhibitory properties and DPPH free-radical-scavenging abilities were isolated and subsequently purified via LC/MS-MS, leading to the identification of over 100 peptide components. In silico screening yielded five ACE inhibitory peptides: FAGDDAPR, QGPIGPR, IFPRNPP, AGFAGDDAPR, and GPTGPAGPR. Among these, IFPRNPP and AGFAGDDAPR were found to be allergenic, while FAGDDAPRR, QGPIGPR, and GPTGPAGP showed good ACE-inhibitory effects. IC50 values for the latter peptides were obtained from HUVEC cells: FAGDDAPRR (IC50 = 262.98 μM), QGPIGPR (IC50 = 81.09 μM), and GPTGPAGP (IC50 = 168.11 μM). Peptide constituents derived from ribbonfish proteins effectively modulated ACE activity, thus underscoring their therapeutic potential. Molecular docking and modeling corroborated these findings, emphasizing the utility of functional foods as a promising avenue for the treatment and prevention of hypertension, with potential ancillary health benefits and applications as substitutes for synthetic drugs. [ABSTRACT FROM AUTHOR]

In this study, alkaline protease enzyme production by a bacterial strain isolated from sludge samples collected from an anaerobic treatment system was investigated. According to the 16S rDNA sequence analysis, the isolate was identified as Thermoanaerobacter thermohydrosulfuricus (98.52%). Enzyme activity analyses revealed an optimum pH value of 10, an incubation time of 64 h, and a temperature of 35°C. Arabinose and casein hydrolysates were found to be the best carbon and nitrogen sources, respectively. Maximum protease activity was recorded (864.68 U/mL) when arabinose was used instead of glucose. Moreover, the addition of 1 g/L MgSO4.7H2O and 0.25 g/L Tween-80 to the medium increased the enzyme activity. Therefore, it can be concluded that T. thermohydrosulfuricus is a significant producer of alkaline protease enzymes in the culture medium. To the best of our knowledge, this is the first study to investigate the optimization of alkaline protease production by T. thermohydrosulfuricus [ABSTRACT FROM AUTHOR]

This study presents a genome analysis identifying various alkaline protease genes and culture condition optimization to enhance the production of the enzyme in Streptomyces barkulensis RC1831. The analysis of genes using bioinformatics tools such as RAST, KEGG, KAAS, and BLASTx revealed the presence of 10 genes that are responsible for alkaline protease production belonging to different families. Multiple sequence alignment showed a high sequence identity with M24 family serine protease followed by subtilisin-like serine protease. Optimal conditions for enhanced protease production were determined to be at 37°C, pH 11, casein1 % (W/V), dextrose 0.5 % (W/V), urea 0.5 % (W/V), tryptophan 1 % (W/V), 1 mM Mn+2, 1 % (V/V) Tween-80 in LB medium and an incubation time of 72 hours. Out of the 10 alkaline protease genes, 2 genes expressed significantly according to the activity observed during optimization processes i.e., M24 family, Mn+2 dependent metalloprotease and subtilisin-like serine, ca+2 dependent metalloprotease. Furthermore, the AP enzyme was remarkably stable in the presence of various cofactors (Metal ions) and surfactants, indicating its potential for industrial applications under diverse conditions.

Saudi Arabia suffers from the spread of diseases linked to clotted blood leaking from slaughtered livestock. Anticoagulant proteases produced by Streptomyces are used to safely dissolve clotted blood. Halophilic Streptomyces isolates were extracted from saline soil in Saudi Arabia and tested to dissolve clotted blood by protease. The most protease-producing isolate was identified using classical and genetic methods. The protease was precipitated with saturated ammonium sulfate from a batch of blood clots inoculated with the most protease-producing isolates. Streptomyces isolates (410) were recovered from thirty saline soil samples collected from Dammam (170 isolates, 41.4 %), Al-Khobar (126 isolates, 30.8 %) and Al-Ahsa (114 isolates, 27.8 %). Proteolytic activity was observed in 305 isolates including the most protease-producing isolate S295, which showed the highest activity (33.8 mm), and was identified as S. violaceoruber (99 % similarity). Among all isolates, 241 showed partial hemolysis (alpha) and 64 showed complete hemolysis (beta), including isolate S295 that presented the highest hemolytic activity (0.58 %). The alkaline protease was precipitated with saturated ammonium sulfate (60 %), and it was found that its activity was 5.2 U/ml, total activity 24,960 U/ml, specific activity 463 U/mg, purification fold 15.2 and yield 78 %. The purified alkaline protease was electrophoresed as a single band at 45 kDa.

The current study aims to exploit the zero-cost inducer wheat bran (WB), an agro-industrial byproduct, for production of alkaline protease (ALK-PR23) by the hyper producer psychrotolerant Lysinibacillus sphaericus Strain AA6 EMCCN3080 for the first time ever. Incubation temperature (25 °C), yeast extract concentration, agitation speed (150 rpm), and aeration ratio [1 volume (liquid):5 volume (Erlenmeyer flask)] provoked ALK-PR23 production; OVAT inferences. The pH, yeast extract, and (NH4)2SO4 levels substantively triggered ALK-PR23 production as deduced from Plackett–Burman design. Incubation time (3 days) and WB [2% (w/v)] were the optimal values inducing positive significant influence on ALK-PR23 as conferred from steepest ascent experiments. Yeast extract (0.446% w/v), (NH4)2SO4 (0.339% w/v), and pH (6.872) prompted ALK-PR23 (592.5 U/mL) with an impressive 98-fold enhancement; Box-Behnken design and ridge steepest ascent path implications. The laboratory validation of the model achieved 100% of the predicted value. Laboratory data would present an eco-friendly, cheap, efficient approach towards concurrent WB recycling and massive production of alkaline protease (ALK-PR23) from L. sphaericus Strain AA6 EMCCN3080. Present data would greatly encourage unveiling biochemical characteristics of ALK-PR23 in prospective studies. [ABSTRACT FROM AUTHOR]

In order to obtain active ingredient sinigrin with high efficiency and high yield from seeds of Thlaspi arvense, the enzymolysis assisted-ultrasonic extraction method was used. The content of sinigrin was determined by high performance liquid chromatography (HPLC). Based on the single factor experiment, enzymolysis time, enzymolysis temperature and enzyme addition amount were the key factors, and the yield of sinigrin was taken as the response value. The Design-Expert 11 software was applied and the Both-Behnken Design response surface methodology was used to optimize the enzymolysis assisted ultrasonic extraction process of sinigrin. The yield of sinigrin was compared with that of ultrasonic and Soxhlet extraction. The results showed that Agilent HC-C18 column (25 mmx4.6 mmx5 µm), mobile phase A methanol, mobile phase B 0.5% phosphoric acid aqueous solution, detection wavelength 215 nm, column temperature 25 °C, flow rate 1 mL⋅min-1, sample size 10 µL, and the same degree elution for 10 min, the separation effect and peak shape were better. Using the screened alkaline protease as enzyme preparation, the optimal extraction conditions were that the enzymolysis temperature was 49 °C, the enzyme dosage was 2.90%, the enzymolysis time was 18 min, the yield of sinigrin was 2.679 mg⋅g-1 under optimal conditions, which was no significant difference with the theoretical value (2.687 mg⋅g-1). The yield of sinigrin was significantly higher than that of ultrasonic extraction (2.036 mg⋅g-1) and Soxhlet extraction (1.702 mg⋅g-1) (P<0.05). The enzymolysis assisted-ultrasonic extraction process of sinigrin from T. arvense was simple, energy saving, ecofriendly, high efficiency and high yield, and it could be applied to the production and utilization of sinigrin from T. arvense, which laid a theoretical foundation for the in-depth development of T. arvense. [ABSTRACT FROM AUTHOR]

Yak whey protein concentrates (YWPCs) have good functional properties, but there is still a gap in the study of their peptides. In this study, peptides were obtained by enzymatic hydrolysis, and the bioactivity of each ultrafiltration fraction was evaluated using an optimal process. YWPCs were isolated and purified from yak milk as the raw material. Alkaline protease, trypsin, and papain were used to hydrolyze YWPCs. The protease with the highest degree of hydrolysis (DH) and peptide concentration was selected as the most suitable enzyme. The effects of pH, temperature, time, and the enzyme-to-substrate ratio (E/S) on the DH and peptide concentration were investigated, and response surface methodology was utilized to optimize the hydrolysis process. The hydrolysate was separated using ultrafiltration membranes with molecular weight cut-offs of 10 kDa, 5 kDa, 3 kDa, and 1 kDa. The bioactivity of each ultrafiltration component was analyzed, including the inhibition rates of α-amylase and xanthine oxidase (XOD) activities and the scavenging rates of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radicals. The results indicated that alkaline protease was the best enzyme for hydrolyzing YWPCs. The peptide concentration in the YWPC hydrolysate was the highest (17.21 mg/mL) at a pH of 8 and a concentration of 7500 U/g, after 2.5 h at 62 °C. The enzymatic hydrolysate was ultrafiltered to yield four peptide fractions, of which the <1 kDa peptides exhibited the highest α-amylase inhibitory activity (22.06%), XOD inhibitory activity (17.15%), and ABTS cationic free radical scavenging rate (69.55%). This demonstrates the potential of YWPC hydrolyzed peptides for hypoglycemic, uric acid-lowering, and antioxidant applications, providing a theoretical basis for the high-value utilization of YWPCs. [ABSTRACT FROM AUTHOR]

The effect of four enzyme preparations: bacillolysin, agroprot, protozyme and protozyme C (Russia) on solubility, emulsifying activity, emulsion stability, foaming and foam stability of isolates prepared from two varieties of peas was studied. It is shown that treatment with enzymes can increase the solubility of isolates at pH 5 by more than 7 times, the index of emulsifying activity at pH 5 by 1.5 to 2 times, and at pH 6 by almost 1.5 times; the stability index of the emulsion increased by about 20% at pH 5, and by 1.7 times (in one of the varieties) at pH 6; foaming increased by 2.4 to 3 times at pH 5, and at pH 6 by 1.8 to 3.7 times; foam stability increased by 25 to 33% at pH 5 and by more than 1.5 times (in one of the varieties) at pH 6. The results obtained made it possible to select an enzyme preparation (bacterial alkaline serine protease) to improve the parameters of pea protein isolates intended for the manufacture of analogs of fermented milk products. [ABSTRACT FROM AUTHOR]

This study was carried out with the aim of covalent immobilization of Aspergillus oryzae beta-galactosidase and Bacillus licheniformis protease on multi-walled amino-carbon nanotubes. In this method, fractional 2k design was used to study the effect of seven continuous factors (activation pH, glutaraldehyde molarity, activation time, buffer solution pH, buffer solution molarity, MWCNT-NH3- glutaraldehyde amount and stabilization time) on the stabilization efficiency and enzyme activity. . Design-expert software was used to analyze data and draw graphs. The results showed that the aforementioned factors predict the level of enzyme activity of Bacillus licheniformis protease and Aspergillus oryzae betagalactosidase with correlation coefficients of 0.80 and 0.92 at the rate of 77 and 88%, respectively. Also, the correlation coefficient of the covalent fixation efficiency model of Aspergillus oryzae beta-galactosidase and Bacillus licheniformis protease on multi-walled carbon nanotubes was 0.89 and 0.82, respectively, and the studied factors were able to determine the covalent fixation beta efficiency, respectively. Aspergillus oryzae galactosidase and Bacillus licheniformis protease on multi-walled amino-carbon nanotubes predict 83 and 77%, respectively. [ABSTRACT FROM AUTHOR]

Aims: Soil metabolites have a great influence on regulating the growth and development of plants and microbes in forest ecosystems. This study aims to reveal the characteristic metabolite profiles and their enriched metabolic pathways in the rhizosphere soil of Masson pine plantations at three different ages. Method: The rhizosphere soil of Masson pine from 10, 31, and 52 years plantation was collected. The metabolites were analyzed using a soil pseudotargeted metabolomics approach and then the relationships between soil metabolites and chemical properties, enzyme activities were established. Results: A total of 172 rhizosphere soil metabolites in 26 classes were identified. There was a decreasing trend in the total concentration of rhizosphere soil metabolites with increasing stand age. Seventy-two characteristic metabolites were screened, mainly saccharides, fatty acids, amino acids, phenolic acids, polyols and terpenoids. Among them, benzoic acid and galactonic acid contributed the most to the young forest, and stearic acid had the greatest influence on the near-mature forest plantation. Erythritol had great effects on the mature forest plantation. Seven metabolic pathways changed with increasing stand age. Correlation analysis showed that available potassium (AK) and soil alkaline protease (S-ALPT) were significantly positively correlated with phenolic acids, polyhydroxy carboxylic acids, etc. Conclusion: The rhizosphere soil of Masson pine had different metabolite profiles at different developmental stages, and the soil nutrient pools were effectively improved. These results provide a reference for plantation management in Masson pine and a deeper understanding of forest metabolic characteristics. [ABSTRACT FROM AUTHOR]

Enzymes derived from microbial sources have gained increasing popularity in industrial applications over the past decades. Despite the high production cost, alkaline proteases have wide applications in industries such as tanneries, food production, and detergents. In recent years, there has been a shift towards utilizing natural carbon sources for cultivating microorganisms and extracting proteases in order to reduce production costs. This study aimed to investigate the biochemical and kinetic properties of protease enzymes obtained from Aspergillus niger cultivated in a paper waste medium and compare with the enzyme produced in a basal medium. Glucose is a more favorable carbon source compared to cellulose, so paper waste was pretreated with cellulose-degrading bacteria to convert cellulose into smaller carbohydrates. After the growth of A. niger in basal and combinational media, the enzymatic properties were compared between the extracted enzymes by using casein as substrate. The results demonstrated that A. niger could produce protease enzymes in the paper waste medium similar to the basal medium with more than 5-fold cost saving. The specific activity of the enzymes isolated from the basal and paper waste media was calculated to be 184.95 ± 10.56 U ml−1 and 169.88 ± 11.05 U ml−1, respectively. Carbon sources did not affect the optimum pH and temperature of the protease enzyme, which were found to be 8 and 37 °C, respectively. This study provides valuable insights into the production of alkaline protease from A. niger using a combinational medium (paper waste pretreated by cellulose-degrading bacteria), offering a cost-effective approach for industrial applications. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Enzymatic additives, particularly alkaline proteases, play a crucial role in enhancing detergent effectiveness against protein-based stains. Despite advancements in enzyme stabilization techniques, there is a need for innovative strategies to further improve protease stability in laundry detergents. However, research exploring the utilization of substrate imprinting technology to achieve this objective remains limited. Therefore, this study aims to enhance the stability of alkaline proteases in laundry detergents by employing casein as an imprinting substrate and utilizing transglutaminase-mediated (TGase) crosslinking to modify proteases 102 and 306. The optimal temperature, pH, and thermal stability of the modified alkaline proteases 102 and 306 showed no significant changes. However, these two modified alkaline proteases exhibited varying degrees of improvement in stability among the 14 detergent additives tested. Under 40 °C incubation for 24 h, the relative enzyme activity of modified alkaline protease 102 increased approximately 1.4–15-fold in AEO-9, BS-12, CMI, APG, FMEE, and SOE, while the relative enzyme activity of modified alkaline protease 306 increased approximately 1.2–3.7-fold across different additives (FMEE, AEO-9, BS-12, SOE, FAA, and AEC-9Na). These modified proteases demonstrated improved stability and wider applicability across commercial detergent formulations available. Integrated into standard laundry detergent at a 1:7 ratio before and after modification, they effectively removed protein stains from the cotton fabric after 24 h of 40 °C incubation. These findings provide insights into more effective stain-removal techniques. [ABSTRACT FROM AUTHOR]

The New Journal of Chemistry, published by The Royal Society of Chemistry and the Centre National de la Recherche Scientifique, focuses on new directions in chemistry. This document is a contents list for the journal, providing information about the ISSN, cover image, and a list of communications and papers featured in the issue. The papers cover a range of topics including lanthanum capture, corrosion inhibition, supercapacitor applications, catalysis, and nanocomposites. Each paper explores a specific scientific concept or mechanism, offering valuable insights into various fields of research. The document also mentions other journals related to energy research and sustainable energy technologies. [Extracted from the article]