Microbial Community in Anaerobic Digestion System: Progression in Microbial Ecology

Anaerobic digestion (AD) is a biochemical process that involves four microorganism groups, namely, hydrolyzers, acidogens, acetogens, and methanogens. These groups function in syntrophy and have intra-dependent metabolic pathways. Changes in one group (e.g., over-/underexpressed population and function) can alter this chain of anaerobic process and consequently AD performance. With recent progress in culture-independent techniques, an array of previously unknown and uncultured microorganisms has been recently uncovered in the AD process. Discoveries on the diversity and structure of the AD microbial community can provide new information on digester stability and performance (e.g., biogas production). This chapter provided a critical analysis of the current knowledge on the AD microbial community, focusing on the factors affecting microbial community and the relationship between microbial community and AD performance. Gaining a better understanding of microbial ecology could be the key for greater AD efficiency and biogas production capacity.