Lignocellulosic hydrolysate based biorefinery for marine exopolysaccharide production and application of the produced biopolymer in environmental clean-up

Abstract

The present study deals with the utilization of lignocellulosic hydrolysate-based carbon source for exopolysaccharide (EPS) production using newly reported marine Echinicola sediminis BBL-M-12. This bacterium produced 7.56 g L–1 and 5.32 g L–1 of EPS on supplementing 30 g L–1 glucose and 10 g L–1 xylose as the sole carbon source, respectively. Whereas on feeding Miscanthus hydrolysate (MCH) with glucose content adjusting to 20 g L–1, E. sediminis BBL-M-12 produced 6.18 g L–1 of EPS. The inhibitors study showed bacterium could tolerate higher concentrations of fermentation inhibitors include furfural (0.05%), 5-hydroxymethylfurfural (0.1%), vanillin (0.1%) and acetate (0.5%). Moreover, the EPS composition was greatly altered with the type and concentration of carbon source supplied, although β-D-Glucopyranose, β-D-Galactopyranose, and β-D-Xylopyranose were the dominant monomers detected. Interestingly, E. sediminis BBL-M-12 EPS revealed excellent environmental applications like clay flocculation, oil emulsification, and removal of humic acid, textile dye, and heavy metal from the aqueous phase.