A Novel Hydrolytic Bacterial Strain for Improved Anaerobic Digestion: Effects Across Different Digester Types

Anaerobic digestion (AD) is a cornerstone technology for sustainable waste management and renewable energy production, yet hydrolysis remains the rate-limiting step in the conversion of complex organic matter to biogas (Appels et al., 2011). Here we isolate and characterize Clostridium hydrolyticumsp. nov., a novel bacterial strain with exceptional extracellular hydrolytic capabilities. Through comprehensive genomic, transcriptomic, and metabolomic analyses, we demonstrate that this strain produces a diverse array of carbohydrate-active enzymes (CAZymes), including novel cellulases, hemicellulases, and proteases with activity across broad pH and temperature ranges. When introduced to mesophilic (35-37 degrees C), thermophilic (50-55 degrees C), and hyperthermophilic (70 degrees C) anaerobic digesters treating agricultural waste, food waste, and sewage sludge, the strain enhanced methane yields by 23-41% and reduced hydraulic retention time requirements by 15-28%. Mechanistic studies reveal that C. hydrolyticumestablishes synergistic relationships with methanogenic archaea through metabolic cross-feeding and biofilm formation (Westerholm et al., 2016). These findings establish C. hydrolyticumas a powerful bioaugmentation agent for improving AD efficiency across diverse operational conditions, with significant implications for the biogas industry and circular economy initiatives.