Systematic metabolic pathway analysis of selective hydrolytic strains for anaerobic fermentation of food waste and identification of molecular markers during stress response

Abstract

Food waste (FW) disposal has become a global social, environmental, and economic problem. Anaerobic digestion (AD) is a promising option to manage FW, and hydrolysis is an important rate-limiting step. In this study, metabolic pathway analysis of selective hydrolase-producing strains was carried out to investigate their hydrolytic capability. Based on metabolic pathway analysis of 10 strains, Bacillus licheniformis DSM13 was identified as the best potential strain for hydrolysis of model substrates. Further, studies were carried out on the protein–protein interactions of key enzymes involved, i.e., triacylglycerol lipase, β-glycosidase, α-amylase, and serine protease, in the metabolic pathway with other proteins in Bacillus licheniformisDSM13 that get activated undercertain stress conditions. Consequently, essential regulators were identified as molecular markers, and metabolic pathways of interacting proteins as a survival strategy under stress were explored. In conclusion, such studies are the key to designing effective strategies for enrichment of specific microbial groups existing in AD.