Microbial population dynamics in urban organic waste anaerobic co-digestion with mixed sludge during a change in feedstock composition and different hydraulic retention times

Abstract

Microbial communities play an essential role in the biochemical pathways of anaerobic digestion processes. The correlations between microorganisms' relative abundance and anaerobic digestion process parameters were investigated, by considering the effect of different feedstock compositions and hydraulic retention times (HRTs). Shifts in microbial diversity and changes in microbial community richness were observed by changing feedstock composition from mono-digestion of mixed sludge to co-digestion of food waste, grass clippings and garden waste with mixed sludge at HRT of 30, 20, 15 and 10 days. Syntrophic acetate oxidation along with hydrogenotrophic methanogenesis, mediated by Methanothermobacter, was found to be the most prevalent methane formation pathway, with the only exception of 10 days' HRT, in which Methanosarcina was the most dominant archaea. Significantly, the degradation of complex organic polymers was found to be the most active process, performed by members of S1 (Thermotogales), Thermonema and Lactobacillus in a reactor fed with a high share of food waste. Conversely, Thermacetogenium, Anaerobaculum, Ruminococcaceae, Porphyromonadaceae and the lignocellulosic-degrading Clostridium were the significantly more abundant bacteria in the reactor fed with an increased share of lignocellulosic biomass in the form of grass clippings and garden waste. Finally, microbes belonging to Coprothermobacter, Syntrophomonas and Clostridium were correlated significantly with the specific methane yield obtained in both reactors.

Air‐side ammonia stripping coupled to anaerobic digestion indirectly impacts anaerobic microbiome

“…B), accompanied by syntrophic bacteria such as those from the proteolytic genus Coprothermobacter (7.7% of CL3), consisting of acetate‐degraders in syntrophic association with hydrogenotrophic methanogens (Ho et al ., ), and Pelotomaculum (4.9% of CL3), a genus of syntrophic propionate‐oxidizing bacteria (Bok et al ., ). Changes in microbial communities linked to transitions from mono‐ to co‐digestion have been previously observed (Fitamo et al ., ) and can be expected given the strong influence of substrates on AD microbial communities (Regueiro et al ., ).…”

Succession of microbial community in anaerobic digestion of dairy manure induced by manure-derived biochar

“…Extensive research has been conducted to enhance the efficiency and stability of AD. For instance, pretreatment [10], co-digestion [11,12] and multi-stage AD (i.e., temperature-phased or separated acidogenic-methanogenic step) [13] have been studied to accelerate the rate-limiting step of AD.…”

Microbial population dynamics in temperature‐phased anaerobic digestion of municipal wastewater sludge

“…However, details of the bacterial populations within those phyla and their ecological roles in the digestion process are yet to be determined. Moreover, the composition of the associated bacterial/methanogenic archaeal community seems to be influenced by process parameters such as temperature, pH and SRT . Therefore, it is valuable to explore the variations in microbial community structure in response to the process parameters during anaerobic digestion of sludge and provide some valid insight into possibly deteriorated performance.…”

“…Moreover, the composition of the associated bacterial/methanogenic archaeal community seems to be influenced by process parameters such as temperature, pH and SRT. [25][26][27] Therefore, it is valuable to explore the variations in microbial community structure in response to the process parameters during anaerobic digestion of sludge and provide some valid insight into possibly deteriorated performance. There are several methods to investigate the microbial community in the environmental samples (soil, sludge and wastewater), including culture-based techniques, conventional microscopy, 4 ′ ,6-diamidino-2-phenylindole (DAPI) epifluorescence microscopy and conventional molecular techniques.…”