Open AccessAnaerobic microbial community response to methanogenic inhibitors 2‐bromoethanesulfonate and propynoic acid
Author(s) -
Webster Tara M.,
Smith Adam L.,
Reddy Raghav R.,
Pinto Ameet J.,
Hayes Kim F.,
Raskin Lutgarde
Publication year - 2016
Publication title -
microbiologyopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.881
H-Index - 36
ISSN - 2045-8827
DOI - 10.1002/mbo3.349
Subject(s) - methanogen , methanogenesis , biology , microbial population biology , 16s ribosomal rna , methanobacterium , euryarchaeota , archaea , microbiology and biotechnology , bacteria , food science , biochemistry , gene , genetics
Methanogenic inhibitors are often used to study methanogenesis in complex microbial communities or inhibit methanogens in the gastrointestinal tract of livestock. However, the resulting structural and functional changes in archaeal and bacterial communities are poorly understood. We characterized microbial community structure and activity in mesocosms seeded with cow dung and municipal wastewater treatment plant anaerobic digester sludge after exposure to two methanogenic inhibitors, 2‐bromoethanesulfonate ( BES ) and propynoic acid ( PA ). Methane production was reduced by 89% (0.5 mmol/L BES ), 100% (10 mmol/ LBES ), 24% (0.1 mmol/ LPA ), and 95% (10 mmol/ LPA ). Using modified primers targeting the methyl‐coenzyme M reductase ( mcrA ) gene, changes in mcrA gene expression were found to correspond with changes in methane production and the relative activity of methanogens. Methanogenic activity was determined by the relative abundance of methanogen 16S rRNA cDNA as a percentage of the total community 16S rRNA cDNA . Overall, methanogenic activity was lower when mesocosms were exposed to higher concentrations of both inhibitors, and aceticlastic methanogens were inhibited to a greater extent than hydrogenotrophic methanogens. Syntrophic bacterial activity, measured by 16S rRNA cDNA , was also reduced following exposure to both inhibitors, but the overall structure of the active bacterial community was not significantly affected.