Search

Background: Microbial growth during plant tissue culture is a common problem that causes significant losses in the plant micro-propagation system. Most of these endophytic microbes have the ability to propagate through horizontal and vertical transmission. On the one hand, these microbes provide a rich source of several beneficial metabolites. Results: The present study reports on the isolation of fungal species from different in vitro medicinal plants (i.e., Breynia disticha major, Breynia disticha, Duranta plumieri, Thymus vulgaris, Salvia officinalis, Rosmarinus officinalis, and Ocimum basilicum l) cultures. These species were tested for their indole acetic acid (IAA) production capability. The most effective species for IAA production was that isolated from Thymus vulgaris plant (11.16 µg/mL) followed by that isolated from sweet basil plant (8.78 µg/mL). On screening for maximum IAA productivity, medium, "MOS + tryptophan" was chosen that gave 18.02 μg/mL. The macroscopic, microscopic examination and the 18S rRNA sequence analysis indicated that the isolate that given code T4 was identified as Neopestalotiopsis aotearoa (T4). The production of IAA by N. aotearoa was statistically modeled using the Box-Behnken design and optimized for maximum level, reaching 63.13 µg/mL. Also, IAA extract was administered to sweet basil seeds in vitro to determine its effect on plant growth traits. All concentrations of IAA extract boosted germination parameters as compared to controls, and 100 ppm of IAA extract exhibited a significant growth promotion effect for all seed germination measurements. Conclusions: The IAA produced from N. aotearoa (T4) demonstrated an essential role in the enhancement of sweet basil (Ocimum basilicum) growth, suggesting that it can be employed to promote the plant development while lowering the deleterious effect of using synthetic compounds in the environment. [ABSTRACT FROM AUTHOR]

The production of the amino polysaccharide (chitosan) from crustacean sources has faced many hindrances due to environmental, seasonal and noneconomic issues. On the other hand, mycogenic chitosan has many advantages that make it suitable for many medical and nutritional applications over the non-mycological counterparts. A number of fungal isolates have been screened for chitosan production, where the most potent fungal isolate has been genetically identified using 18S rDNA and selected to be the focus of the current study. The factors affecting chitosan production by the selected fungal isolate have been studied and numerically optimized and validated using Box–Behnken design. The produced chitosan has been collected, purified and characterized for the degree of deacetylation (DDA), molecular weight (MW), water-binding (WBC) and fat-binding capacities (FBC). Results showed that Aspergillus terreus (F3) was the most potent chitosan-producing fungal isolate with maximum validated productivity (2.92 g/l) at the following conditions: glucose, 35.6 g/l; (NH4)2SO4, 4.6 g/l; CaCl2, 0.29 g/l; and pH 7.9 at 23.2 °C for 10 days. The purified chitosan has the following characteristics: 71.9%, DDA; 54.1165 KD, MW; 58.6%, WBC; and 47.6%, FBC. The features and applications of fungal chitosan are not fully uncovered which necessitates further studies. [ABSTRACT FROM AUTHOR]

There is an increasing desire for bioplastics produced from renewable resources as an alternative to their petrochemical counterparts. These biopolymers have long-unnoticed antiviral properties. This study aimed to produce and characterize bioplastics by Parageobacillus toebii using low-cost substrates and determine their antiviral activity against coxsackievirus B4. Seven low-cost substrates (bagasse, water hyacinth, rice straw, rice water, sesame husks, molasses, and corn syrup) were compared with glucose for bioplastic precursor production. The highest bioplastic produced was from water hyacinth and glucose, followed by molasses, rice straw, rice water, sesame husks, and bagasse. Water hyacinth and glucose media were further optimized to increase the bioplastic precursor yield. The optimization of the media leads to increases in bioplastic precursor yields of 1.8-fold (3.456 g/L) and 1.496-fold (2.768 g/L), respectively. These bioplastics were further characterized by thermogravimetric analysis (TGA), Fourier-transformed infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR), and gas chromatography–mass spectrometry (GC–MS). They are thermostable, and their characterizations confirm the presence of polyhydroxybutyrate. The antiviral assay showed reasonable antiviral effects for bioplastics from water hyacinth (80.33 %) and glucose (55.47 %) media at 250 μg/mL maximum non-toxic concentrations (MNTC). The present investigation demonstrates a low-cost model for producing polyhydroxybutyrate bioplastic precursor for antiviral applications. [ABSTRACT FROM AUTHOR]

Inflammation is a part of the body's intricate biological reaction to noxious stimuli and defensive reactions. So, the aim of this investigation was to study the anti-inflammatory activity of exopolysaccharide (EPSSM) using carrageenan-induced paw edema in rats. A halophilic bacterial strain was isolated from marine sediments in the Red Sea in Egypt. The isolate has been visually and physiologically recognized, as well as by analyzing its 16S rRNA gene, which confirms Kocuria sp. clone Asker4. This particular isolate can be referenced using the accession number OL798051.1. EPSSM was subjected to purification and fractionation by a DEAE-cellulose column. Preliminary chemical analysis of EPSSM indicated that the monosaccharides were fructose, glucuronic acid, and xylose, with 2.0, 0.5, and 1.0, respectively. The antioxidant potential of EPSSM was investigated, and it was discovered that the level of activity increased independently of the concentrations, reaching a maximum threshold of 94.13% at 100 µg/mL of EPSSM for 120 min. Also, EPSSM at 50 mg/kg orally produced a significant anti-inflammatory effect on the carrageenan model at 2, 3, and 4 intervals. The EPSSM intervention resulted in reductions in the levels of catalase and superoxide dismutase enzymes, as well as a decrease in glutathione. Furthermore, the levels of nitric oxide, lipid peroxidation, and reactive oxygen species resulting from carrageenan-induced edema showed a significant reduction subsequent to the administration of EPSSM. Moreover, the findings indicated that the protein expression levels of cyclooxygenase-2 and interleukin-6 were reduced following treatment with EPSSM, resulting in a reduction of paw edema. [ABSTRACT FROM AUTHOR]

Background: Chitin and chitosan are natural biopolymers found in shell of crustaceans, exoskeletons of insects and mollusks, as well as in the cell walls of fungi. These biopolymers have versatile applications in various fields such as biomedical, food industry, and agriculture. These applications are back to their biocompatibility, biodegradability, strong antibacterial effect, and non-toxicity. Outcomes: The fungal biopolymers have many features that made them more advantageous than those biopolymers from seafood waste origin. Chitin and chitosan are not components of cell wall in all fungal species. The fungal classes of Basidiomycetes, Ascomycetes, Zygomycetes, and Deuteromycetes are known to contain chitin and chitosan in their cell walls. The amounts and characters of fungal biopolymers are affected by many factors so they should be optimized before increasing the scale of production. The statistical design of experiments is the most recent and advanced approach for optimization of various factors with more reliable results. Conclusion: Although extensively studied, further studies concerning fungal chitin and chitosan should be conducted in order to be sure of safety for human use. [ABSTRACT FROM AUTHOR]

Background: L-arginase, is a powerful anticancer that hydrolyzes L-arginine to L-ornithine and urea. This enzyme is widely distributed and expressed in organisms like plants, fungi, however very scarce from bacteria. Our study is based on isolating, purifying, and screening the marine bacteria that can produce arginase. Results: The highest arginase producing bacteria will be identified by using microbiological and molecular biology methods as Bacillus licheniformis OF2. Characterization of arginase is the objective of this study. The activity of enzyme was screened, and estimated beside partial sequencing of arginase gene was analyzed. In silico homology modeling was applied to generate the protein's 3D structure, and COACH and COFACTOR were applied to determine the protein's binding sites and biological annotations based on the I-TASSER structure prediction. The purified enzyme was undergone an in vitro anticancer test. Conclusions: L-arginase demonstrated more strong anti-cancer cells with an IC50 of 21.4 ug/ml in a dose-dependent manner. L-arginase underwent another investigation for its impact on the caspase 7 and BCL2 family of proteins (BCL2, Bax, and Bax/Bcl2). Through cell arrest in the G1/S phase, L-arginase signals the apoptotic cascade, which is supported by a flow cytometry analysis of cell cycle phases. [ABSTRACT FROM AUTHOR]

Biofuel production has attracted much attention in the last few decades. Much effort has been applied to decrease the production cost of bioethanol by using agricultural waste materials. Saccharification of lignocellulosic agricultural waste materials increases the amount of available sugars and thus reduces bioethanol production costs. Here, about 14 g/l of bioethanol (185 mg/g of dry material) was produced by Candida tropicalis Y-26 using production medium with water hyacinth hydrolysate as the sole carbon source. This hydrolysate was produced, after screening and mathematical modeling, by a combination of Aspergillus terreus F-98 and acid hydrolysis (H2SO4) treatments to give 409 mg/g total reducing sugars. The use of a combination of A. terreus F-98 and acid hydrolysis with H2SO4, 4.66% (v/v); water hyacinth biomass, 7.56% (w/v); reaction temperature, 119.27∘C; and reaction time, 16.11 min was optimal for the saccharification of water hyacinth. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are among the most widely biosynthesized and used nanomaterials. They have different unique properties and a wide range of applications. This study is concerned with optimization of the growth conditions of Bacillus subtilis NRC1 for the biosynthesis of AgNPs using two designs of response surface methodology (RSM) statistical analysis. The data obtained from Plackett-Burman design (PBD) followed by central composite design (CCD), showed a good agreement between the experimental and predicted values of AgNPs biosynthesis. The optimum conditions were 0.7% (w/v) casein hydrolysate, 5% dextrin (w/v), pH 7.5 and 57 × 106 CFU/ml inoculum size. The model was highly valid and could be applied with a confidence factor of 99.47%. Minimal inhibitory concentration (MIC) of these AgNPs synthesized using the extracellular filtrate after growth of Bacillus subtilis NRC1 in the optimized medium was found to be 41–43µg/ml for all tested microorganisms with exception of Pseudomonas aeruginosa where MIC was 169 µg/ml. [ABSTRACT FROM AUTHOR]

Selenium is an essential trace element, but its oxyanions, selenite [SeO 3 2−] or selenate [SeO 4 2−], are ecologically toxic. Different microorganisms were reported to transform the soluble toxic selenite or selenate to the insoluble less toxic elemental selenium (Se0), forming selenium nanoparticles (SeNPs). In the present study, we isolated a selenate-reducing bacterial strain from Egyptian soil that showed remarkable tolerance for elevated sodium selenate concentration (40 mM). The treatment of the bacterial cells with 1 kGy gamma irradiation attained an extra ~10% SeNPs yield throughout 72 h. Furthermore, the irradiation improved the selenate reduction rate where almost half of the anions were reduced at the first 28 h of the incubation period, versus about 44 h by the control cells. The UV–Vis spectra of the SeNPs generated by the irradiated and non-irradiated cultures showed distinct variation. The XRD and Raman spectroscopy of the two generated nanoparticles proved the irradiation influence on the crystalline structures of the SeNPs. The FESEM, EDX, TEM, and DLS revealed that gamma irradiation has a serious impact on the size, shape, and composition of the generated SeNPs. Zeta potential showed that both generated SeNPs had negative charges but with different values, while FTIR inspection exhibited similar profiles for both types of SeNPs. Both the control and irradiated SeNPs exhibited diversified antimicrobial impact, which markedly peaked against Gram-positive test organisms with values greater than the antimicrobial test control. The cytotoxicity of the synthesized SeNPs versus the WI38 cell line and antiviral activities against adenovirus-9 were also inspected. [Display omitted] • Bacillus niabensis OAB2 is identified as a novel selenium nanoparticles bio-producer. • Gamma irradiated cells generated selenium nanoparticles with different characters. • The biogenic selenium nanoparticles exhibited considerable antimicrobial impact. • WI38 human cell line affected by the non-irradiated selenium nanoparticles. • Adenovirus-9 showed susceptibility towards the non-irradiated selenium nanoparticles. [ABSTRACT FROM AUTHOR]

Background: The aim of the current study based on the production and characterization of exopolysaccharides (EPSs) isolated from marine sediment of the Mediterranean and Red Seas is to study its cytotoxic activity against HepG2 cells. Results: Eleven isolates have the ability to produce EPSs and also decreased the viability of HepG2 cell line in different manners. The five most promising isolates that produce high yield of EPSs and high cytotoxicity were identified by 16S RNA as Brevundimonas subvibrioides MSA1, Bacillus thuringiensis E4, Bacillus amyloliquefaciens MGA2, Pseudomonas fluorescens SGA3, and Advenella Kashmirensis NRC-7. The chemical composition of the following EPSs (M1, M3, M6, M15, M19, E2, E4, E10, S5, S7, and S11) demonstrates that they are acidic sulfated heteropolysaccharides with different relative ratios of monosugars of glucose, mannose, galactose, glucouronic acid, and mannouronic acid. The average molecular weights from 1.94 × 104 to 7.95 × 105 g/mol and the number average molecular weight from 1.51 × 104 to 7.53 × 105 g/mol. FTIR spectrum of the five EPSs indicated the presence of sulfate and carboxylic groups in different percentages. Conclusions: The EPSs produced from marine bacteria are very promising for treating the HepG2 cells. [ABSTRACT FROM AUTHOR]