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Effects of ammonia on propionate degradation and microbial community in digesters using propionate as a sole carbon source
Author(s) -
Li Ying,
Zhang Yue,
Kong Xiaoying,
Li Lianhua,
Yuan Zhenhong,
Dong Renjie,
Sun Yongming
Publication year - 2017
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.5260
Subject(s) - propionate , methanogen , chemistry , methanogenesis , ammonia , hydraulic retention time , degradation (telecommunications) , microbial population biology , methane , food science , environmental chemistry , pulp and paper industry , environmental engineering , wastewater , biochemistry , bacteria , organic chemistry , biology , environmental science , telecommunications , computer science , engineering , genetics
BACKGROUND Propionate accumulation may lead to digester failure. This study aimed to investigate the effect of ammonia, a metabolic product of protein, on propionate degradation. The shift of microbial community was also investigated. RESULTS Propionate accumulated over the experimental period in the reactor with a total ammonia nitrogen ( TAN ) concentration of 2.5 g N L −1 , as a result the digester failed after 4 hydraulic retention times ( HRT ) at an organic load rate ( OLR ) of 0.8 g propionic acid ( HPr ) L −1 d −1 . The average HPr degradation rate was below 54% during the fourth HRT , while >97% of the degraded HPr was converted to methane. The reactor without ammonia stress did not experience HPr accumulation and OLR was increased stepwise to 1.2 g L −1 d −1 at the 8th HRT . The average HPr degradation rate and methane recovery rate of this reactor in the last HRT was 99% and 74%, respectively. According to the shifts of microbial community, acetoclastic methanogen was more vulnerable to ammonia than hydrogenotrophic methanogen CONCLUSION TAN concentration of 2.5 g N L −1 inhibited propionate degradation more severely than methanogenesis. The loss of abundance of Clostridiaceae and Syntrophobacter might be the main reason for the poor performance under ammonia stress. © 2017 Society of Chemical Industry