Study of Exopolysaccharide produced by a marine bacterium for development of biopolymer films

With the advent and growing popularity of fast foods and comfort foods, the volume of petrochemical based plastics has increased significantly in the packaging industries. However, the limited recyclability and non-biodegradable nature of these plastics has raised serious environmental concerns. Although these synthetic polymers offer excellent mechanical and thermal properties, the associated harmful environmental effects advocate the need for sustainable alternatives such as microbial derived biopolymers. The present study aimed at isolation of exopolysaccharide (EPS) producing bacteria from various sources for development of biopolymer films. The highest yield of EPS among 15 isolates screened in this study was obtained from a marine bacterium, identified as Vibrio tritonius based on molecular methods. Under optimised conditions of inoculum size (0.5 OD and 7ml volume), media (pH 7.5; supplemented with 4% galatose, 1% ammonium sulphate and 1% tryptone) and incubation conditions (under shaker for 48h), V. tritonius yielded 0.54g% EPS. Following purification, a 53.4% reduction in EPS weight was observed indicating successful removal of proteins and salts. The purified EPS was 0.46mm thick, smooth, with 34.62% moisture content, flexible and translucent (transparency of 1.64). It was completely soluble within 6 h in water. The observed properties of biopolymer film were comparable to kefiran, fucopol and Pseudomonas derived biopolymers. Overall, the findings of this study highlight the potential of obtained EPS as an eco-friendly alternative to petrochemical based plastics