Open AccessMesophilic versus thermophilic anaerobic digestion of cattle manure: methane productivity and microbial ecology
Author(s) -
Moset Veronica,
Poulsen Morten,
Wahid Radziah,
Højberg Ole,
Møller Henrik Bjarne
Publication year - 2015
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12271
Subject(s) - mesophile , anaerobic digestion , manure , thermophile , clostridia , microbial population biology , methane , chemistry , hydraulic retention time , food science , biogas , organic matter , methanogenesis , pulp and paper industry , agronomy , biology , environmental science , bacteria , ecology , wastewater , environmental engineering , genetics , engineering
Summary In this study, productivity and physicochemical and microbiological (454 sequencing) parameters, as well as environmental criteria, were investigated in anaerobic reactors to contribute to the ongoing debate about the optimal temperature range for treating animal manure, and expand the general knowledge on the relation between microbiological and physicochemical process indicators. For this purpose, two reactor sizes were used (10 m 3 and 16 l), in which two temperature conditions (35°C and 50°C) were tested. In addition, the effect of the hydraulic retention time was evaluated (16 versus 20 days). Thermophilic anaerobic digestion showed higher organic matter degradation (especially fiber), higher pH and higher methane ( CH 4 ) yield, as well as better percentage of ultimate CH 4 yield retrieved and lower residual CH 4 emission, when compared with mesophilic conditions. In addition, lower microbial diversity was found in the thermophilic reactors, especially for B acteria , where a clear intensification towards C lostridia class members was evident. Independent of temperature, some similarities were found in digestates when comparing with animal manure, including low volatile fatty acids concentrations and a high fraction of E uryarchaeota in the total microbial community, in which members of M ethanosarcinales dominated for both temperature conditions; these indicators could be considered a sign of process stability.