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

• Published in: International journal of biological macromolecules 2021-01, Vol.166, p.1471-1479
• Main Authors: Sathishkumar, Ramamoorthy, Kannan, Ramachandran, Jinendiran, Sekar, Sivakumar, Natesan, Selvakumar, Gopal, Shyamkumar, Rajaram
• Format: Article
• Language: English
• Subjects: Animals; Anticoagulant; Anticoagulants - chemistry; Anticoagulants - pharmacology; Anticoagulants - toxicity; Antioxidant; Antioxidants - chemistry; Antioxidants - pharmacology; Antioxidants - toxicity; Bacillus subtilis; Bacillus subtilis - chemistry; Bacillus subtilis - isolation & purification; Bacillus subtilis - pathogenicity; Erythrocytes - drug effects; Exopolysaccharides; Hemolysis; Humans; Lymphocytes - drug effects; Polysaccharides, Bacterial - chemistry; Polysaccharides, Bacterial - pharmacology; Polysaccharides, Bacterial - toxicity; Porifera - microbiology; Sponge
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.11.026

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. •Bioactive exopolysaccharide was obtained from sponge associated B. subtilis MKU SERB2.•EPS production was optimized by Response Surface Methodology (RSM).•The physiochemical nature of EPS was characterized by NMR, FT-IR, SEM, and XRD.•EPS exhibited potent antioxidant and anticoagulant property.•Isolated EPS has no toxic effect on lymphocyte and red blood cells.