Bioaugmented degradation of rice straw combining two novel microbial consortia and lactic acid bacteria for enhancing the methane production.

[Display omitted] • Two microbial consortia with high lignocellulolytic capability were enriched. • Combined with LAB, these consortia facilitated biodegradability of rice straw. • Bioaugmentation improved mono- and disaccharide contents and enzymatic hydrolysis. • Synergistic action of microbial consortia and LAB enhanced methane production. Two consortia of lignocellulolytic microbes (CL and YL) were isolated from the rumen of ruminants. Their ability to facilitate the degradation of rice straw and enhance methane (CH 4) production were evaluated, both individually and combined with lactic acid bacteria (LAB). After 30 days of degradation, rice straw powders (RSPs) were observed to change in physical structure and also displayed a significant reduction in lignocellulose content. Combined application of microbial consortia with LAB efficiently improved enzymatic hydrolysis of RSPs, increasing organic acid as well as mono- and disaccharide contents. Synergistic action between microbial consortia and LAB enhanced CH 4 yield, and rice straw treated with YL + LAB had the highest CH 4 production (357.53 mL CH 4 /g VS), more than fivefold of the control. The newly identified microbial consortia are capable of efficiently degrading lignocellulosic biomass. Functioning synergistically with LAB, they provide a feasible way biodegrade rice straw and enhance methane production from agricultural wastes. [ABSTRACT FROM AUTHOR]