TEMPORAL VARIATION IN BACTERIAL COMMUNITIES OF FULL-SCALE THERMOPHILIC ANAEROBIC DIGESTER TREATING FOOD WASTE-RECYCLING WASTEWATER

摘要

Bacteria communities were investigated in full-scale thermophilic anaerobic digester treating food waste-recycling wastewater (FRW) using 454 pyrosequencing. Seasonal samples were collected for 2 years, and temporal variations of bacteria were analyzed at genus level. FRW consisted of carbohydrate (35% of volatile solids), protein (34%) and lipid (30%). Protein was not well degraded (38%) compared to carbohydrate (90%) and lipid (60%). Sodium ion originated from FRW had negative correlation with COD removal, and, above 7.0 g/L of sodium ion, process performance was notably inhibited. A total of 58 342 bacteria sequences was obtained, and 56 778 reads for 11 phyla and 37 572 reads for 129 genera were determined. Anaerobaculum (16.9 ± 13.0%), Tepidanaerobacter (16.2 ± 12.0%), Tepidimicrobium (11.8 ± 8.4%), Gelria (6.4 ± 5.7%), Caldicoprobacter (2.8 ± 1.1%), Thermacetogenium (2.5 ± 2.2%), Candidatus Microthrix (2.0 ± 3.8%), and Bacillus (1.5 ± 3.5%) were observed. Hydrogenotrophic methanogenesis based on syntrophic relationship with T. acetatoxydans is the main metabolic pathway to generate methane in this system. Unlike methanogen, bacteria community structure shifted in relation with process performance.