Recent advance on the production of microbial exopolysaccharide from waste materials

Polysaccharide has been widely used in the fields of industry, agriculture, food and medicine because of its excellent physicochemical properties and bioactivities. Compared to plant and animal polysaccharides, microbial exopolysaccharide has advantages of occupying less cultivated land, short fermentation period, controllable fermentation process and not restricted by seasons. However, due to the deterioration of global climates and outbreak of conflicts, food crisis has become more and more serious. Therefore, searching alternative substrates for microbial exopolysaccharide production has attracted worldwide attention, waste materials might be an ideal substitute due to its high-content nutrients. Present work discussed and reviewed the production of microbial exopolysaccharide from molasses, cheese whey, lignocellulosic biomass, fruit pomace and/or husk, crude glycerol and kitchen waste. It was found that commercial grade exopolysaccharides were mainly produced from waste materials via submerged fermentation, and pretreatment of waste materials is a commonly used strategy. Although industrial production of microbial exopolysaccharides with waste materials as substrate has not been reported, we hoped that this work could not only provide contribution for efficient utilization of waste materials, but also help for alleviating global food crises.