Premium
Effect of nitrate and nitrite on the selection of microorganisms in the denitrifying anaerobic methane oxidation process
Author(s) -
Hu Shihu,
Zeng Raymond J.,
Keller Jurg,
Lant Paul A.,
Yuan Zhiguo
Publication year - 2011
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/j.1758-2229.2010.00227.x
Subject(s) - denitrifying bacteria , nitrite , nitrate , anaerobic oxidation of methane , bacteria , biology , archaea , microorganism , anaerobic exercise , denitrification , microbiology and biotechnology , environmental chemistry , food science , methane , chemistry , ecology , nitrogen , physiology , organic chemistry , genetics
Summary Two cultures were inoculated with sludges taken from a parent culture containing archaea distantly related to anaerobic methanotrophic archaea (ANME) and bacteria related to Candidatus Methylomirabilis oxyfera, both of which have previously been found in cultures performing denitrifying anaerobic methane oxidation process. The cultures were fed with nitrate and nitrite, respectively, along with methane. The nitrate‐fed culture, Culture B, showed a stable microbial community composition and denitrifying anaerobic methane oxidation activity. In contrast, the nitrite‐fed culture, Culture A, achieved a substantial increase in the nitrite consumption rate, from 1.1 to 7.3 mmol NO 2 ‐ ‐N (g VSS) −1 day −1 in 90 days. Concurrent with this activity increase, the archaeal population in Culture A decreased with time, and became undetectable after 100 days, while bacteria related to M. oxyfera increasingly dominated the culture. This observation suggests that the bacteria related to M. oxyfera are more competitive for nitrite reduction compared with the archaea related to ANME. This study showed that nitrate or nitrite feeding has a significant impact on the ecology and activities of microorganisms in the denitrifying anaerobic methane oxidation process. This study also revealed that nitrite overloading may have a toxic effect on the bacteria related to M. oxyfera .