Assessment of bioactivity of the novel exopolysaccharide secreted by Bacillus subtilis isolated from the gut of marine anchovies

Abstract

The current work focuses on the isolation, characterization, and purification of an exopolysaccharide secreted by a novel bacterium isolated from dried anchovies. The bacterium was identified as Bacillus subtilis using 16S sequencing. B. subtilis in MRS medium produced exopolysaccharide (EPS), which gave a maximum yield of 1928 mg/L. The total molecular weight of the polysaccharide present was around 20 kDa. Fourier-transform infrared spectroscopy of the EPS displays the existence of methylene, carboxyl, and hydroxyl groups. Atomic force microscopy indicates a highly cross-linked structure with lumps. Scanning electron microscopy studies showed a coarse surface. The EPS also showed emulsification potential. This study shows that the EPS is a prospective candidate for further studies on their applications.