The metabolic performance and microbial communities of anaerobic digestion of chicken manure under stressed ammonia condition: a case study of a 10-year successful biogas plant

Abstract To increase the knowledge of microbial adaptation for high degradation ability under ammonia stressed conditions, the metabolic performance and the microbial community in a full-scale chicken manure anaerobic digestion (AD) plant, operated over a 10-year, were investigated. The methanogenic pathway employing labeled acetate (2-13C), aceticlastic methanogenesis activity, and the Illumina sequencing of microbiome structure at the plant were analyzed. The obtained results show that this active plant achieved a methane yield of 310±43 mL/g-volatile solids (VS), high stability under an ammonium-N level of 6.2±0.1 g/L, and an organic loading rate of 2.5 g-VS/(L·d). The extremely long adaptation developed the unique microbe communities, and the hydrogentrophic methanogens Methanobrevibacter (76%) and Methanoculleus (18%) were dominant in the main digester. The acetoclastic methanogenic pathway reached 42%, contributing to the deep degradation. The current study thus may lay the foundation for illustrating the successful full-scale AD of nitrogen-rich materials under stressed operating conditions.