Statistical optimization of exopolysaccharides by indigenously isolated Lactobacillus strain under submerged fermentation.

Exopolysaccharides are classified as high molecular weight polymers of carbohydrates. The aim of the present study was the isolation of exopolysaccharides (EPS) producing strain from fruits and vegetables indigenously and optimization of physical parameters for the hyperproduction of EPS. Yeast Industrial wastewater from AB Mauri (Associated British Foods) was used as substrate for the production of EPS. Fruits and vegetables source were used for isolation of Lactobacillus strain. The morphological examination and 16 S RNA sequence analysis were used to identify the isolated Lactobacillus strain. The screening of nitrogen (organic, inorganic) was carried out for the production of EPS. A statistical approach of optimization the Response Surface Methodology (RSM) was applied to optimize the physiochemical parameters such as nitrogen concentration, pH, temperature, and incubation period in order to maximize the production. Further the effect of various parameters were studied at lab scale bioreactor to enhance the production. Isolated strain was gram positive rods and identified as Lactobacillus fermentum-MH473306.1. It was determined that urea as the best source of nitrogen. The optimized condition for maximum production of EPS the ideal pH, temperature, nitrogen supply, and incubation period were 7, 35 °C, 1.5%, and 35 h, respectively. Almost 2 folds increase in EPS production was observed after optimization of this optimal condition by RSM. Lab scale bioreactor revealed maximum production of EPS at 200 rpm and 72 h by the isolated strain of L. fermentum MH473306. It is concluded that RSM is a better technique for optimization of EPS as compared to other technique of optimization.