Production and characterization of exopolysaccharide from the sponge-associated Bacillus subtilis MKU SERB2 and its in-vitro biological properties.

In this study, the sponge-associated a potential endosymbiotic bacterium, Bacillus subtilis MKU SERB2 was identified and optimized the production of exopolysaccharide (EPS) by using response surface methodology (RSM). The central composite rotatable design (CCRD) exhibited the highest yield of EPS (617.81 µg/mL) obtained from the optimized medium containing 11.5 g/L of sucrose, 3.5 g/L of yeast extract, 3.0 g/L of peptone, and 2.5 g/L of calcium chloride. Fourier transform infrared (FTIR) spectrum of purified EPS indicated that the presence of carboxyl, hydroxyl, and amide as functional groups, and their structural composition was confirmed by 1H and 13C nuclear magnetic resonance (NMR) analysis. Moreover, the fibrous, porous and semi-crystalline nature of EPS was confirmed by SEM and X-ray powder diffraction (XRD) analysis and the EDX inferred demonstrated the presence of C, Na, O, N, S, and Cl respectively. Further, the isolated EPS exhibited potent antioxidant activity and moderate anticoagulant efficacy whereas there was no hemolytic and lymphocytes toxicity. Overall, our result suggests that the functional and biological properties of the EPS imply the potential applications in food and pharmaceutical industries in the future.

Production of L-glutamic Acid with Corynebacterium glutamicum (NCIM 2168) and Pseudomonas reptilivora (NCIM 2598): A Study on Immobilization and Reusability.

BACKGROUND: L-glutamic acid is one of the major amino acids that is present in a wide variety of foods. It is mainly used as a food additive and flavor enhancer in the form of sodium salt. Corynebacterium glutamicum (C. glutamicum) is one of the major organisms widely used for glutamic acid production. METHODS: The study was dealing with immobilization of C. glutamicum and mixed culture of C. glutamicum and Pseudomonas reptilivora (P. reptilivora) for L-glutamic acid production using submerged fermentation. 2, 3 and 5% sodium alginate concentrations were used for production and reusability of immobilized cells for 5 more trials. RESULTS: The results revealed that 2% sodium alginate concentration produced the highest yield (13.026±0.247 g/l by C. glutamicum and 16.026±0.475 g/l by mixed immobilized culture). Moreover, reusability of immobilized cells was evaluated in 2% concentration with 5 more trials. However, when the number of cycles increased, the production of L-glutamic acid decreased. CONCLUSION: Production of glutamic acid using optimized medium minimizes the time needed for designing the medium composition. It also minimizes external contamination. Glutamic acid production gradually decreased due to multiple uses of beads and consequently it reduces the shelf life.

Antibacterial effect of Allium sativum cloves and Zingiber officinale rhizomes against multiple-drug resistant clinical pathogens

Objective: To evaluate the antibacterial properties of Allium sativum (garlic) cloves and Zingiberofficinale (ginger) rhizomes against multi-drug resistant clinical pathogens causing nosocomial infection. Methods: The cloves of garlic and rhizomes of ginger were extracted with 95% (v/v) ethanol. The ethanolic extracts were subjected to antibacterial sensitivity test against clinical pathogens. Results: Anti-bacterial potentials of the extracts of two crude garlic cloves and ginger rhizomes were tested against five gram negative and two gram positive multi-drug resistant bacteria isolates. All the bacterial isolates were susceptible to crude extracts of both plants extracts. Except Enterobacter sp. and Klebsiella sp., all other isolates were susceptible when subjected to ethanolic extracts of garlic and ginger. The highest inhibition zone was observed with garlic (19.45 mm) against Pseudomonas aeruginosa (P. aeruginosa). The minimal inhibitory concentration was as low as 67.00 μg/mL against P. aeruginosa. Conclusions: Natural spices of garlic and ginger possess effective anti-bacterial activity against multi-drug clinical pathogens and can be used for prevention of drug resistant microbial diseases and further evaluation is necessary.