Inoculating domesticated natural bacterial improved short-chain carboxylic acids yield: Focusing on solid content and bacterial consortia

To enhance the conversion efficiency and operational stability of the biomass refining process, this study investigated the effects of two domesticated bacterial consortia on the degradation of rice straw (RS) and the production of short-chain carboxylic acids (SCCAs) were investigated and further analyzed the key genes involved in biomass conversion. The results indicate that inoculating both the domesticated straw-degrading microorganisms (SDM) and the acid-producing microorganisms (APM) into the straw fermentation system with a total solids (TS) content of 5 wt% resulted in the maximum yield of SCCAs on the 6th day, reaching 186.46 mg/g TS. The key genes change found that an increase in the abundance of key genes such as pta (phosphotransacetylase), ack (acetate kinase) and ldh (lactate dehydrogenase) contributed to the efficient biomass conversion of the consortium. In addition, the high abundance of Enterococcaceae (92.70 %) and Lactobacillaceae (97.90 %) contributed to better RS degradation and acid production during anaerobic fermentation (AF). This study indicated that SDM and APM could improve performance and achieve higher SCCAs during AF. • Domesticated two bacterial consortia to enhance the degradation of rice straw (RS). • The performance of bacterial consortia in anaerobic fermentation was investigated. • The utilization rate of RS was the highest when the total solids (TS) was 5 wt%. • The highest yield of SCCAs for the SDM+APM group was 186.46 mg/g TS.