Microbial Interactions in Anaerobic Wastewater Treatment

Abstract

Anaerobic treatment technology, represented by anaerobic digestion, is an important microbial process for wastewater treatment. Anaerobic treatment is superior to aerobic processes with reduced energy demand, lower excess sludge production, and the generation of methane as a source of renewable energy. In anaerobic treatment, organic waste is converted into methane and carbon dioxide via four successive steps – hydrolysis, acidogenesis, acetogenesis, and methanogenesis. The interactions between microbial populations have major impacts on the performance of anaerobic treatment processes. The competition between populations of Firmicutes and Bacteroidetes is closely correlated to process stability. Similarly, the competition between two acetoclastic methanogens with distinct kinetics characteristics, i.e. Methanosaeta and Methanosarcina , is linked to changes in the level of acetate as a metabolic intermediate associated with process perturbations. Further, syntrophic interactions between the Bacteria and Archaea play central roles in maintaining process balance. Indeed, syntrophic interactions are required for the conversion of diverse intermediates and substrates, including organic acids, alcohols, and aromatics, in anaerobic treatment. The microbial interactions underlying anaerobic treatment are critical to process performance. The availability of new tools, such as high‐throughput sequencing technologies, makes it possible to gain further understanding of population interactions at the microbiome level in order to develop more robust anaerobic treatment processes for broader applications as sustainable alternatives.