DEXTRAN PRODUCTION BY MICROBIAL BIOTRANSFORMATION OF SUGARCANE WASTE

Abstract

Natural biopolymers have gained worldwide importance as multipurpose polysaccharides. The demand for natural polymers by different industries around the world is increasing day by day, leading to new avenues in research on microbial exopolysaccharides (EPS). Current study attempted for the isolation of dextran producing microorganisms from indigenous resources and optimization of major parameters affecting polymer production. 17 bacterial strains were isolated from various food samples. Higher dextran producing strain identified as Leuconostoc mesenteroides X21. It was found that L. mesenteroides X21 produces higher quantity of biopolymer in static condition at 30 °C for 24 h in slightly basic condition i.e. at pH 7. Inclusion of molasses into nutrient medium along with sucrose resulted in 2.28 times higher biopolymer yield. The total carbohydrates and reducing sugar content estimated also revealed an efficient transfer of available carbon into biopolymer production by the strain. This study presents an eco-friendly and cost-effective process for commercial production of dextran utilizing molasses as cheap substrate.