title: Anaerobic microbial community response to methanogenic inhibitors 2-bromoethanesulfonate and propynoic acid.
abstract: 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.
authors.affiliation: Civil & Environmental Engineering Department, University of Michigan, Ann Arbor, Michigan.
authors.forename: Tara M
authors.identifier: 0000-0003-0063-337X
authors.initials: TM
authors.lastname: Webster
authors.affiliation: Civil & Environmental Engineering Department, University of Michigan, Ann Arbor, Michigan.
authors.forename: Adam L
authors.initials: AL
authors.lastname: Smith
authors.affiliation: Civil & Environmental Engineering Department, University of Michigan, Ann Arbor, Michigan.
authors.forename: Raghav R
authors.initials: RR
authors.lastname: Reddy
authors.affiliation: Infrastructure and Environment Research Division, School of Engineering, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Ameet J
authors.initials: AJ
authors.lastname: Pinto
authors.affiliation: Civil & Environmental Engineering Department, University of Michigan, Ann Arbor, Michigan.
authors.forename: Kim F
authors.initials: KF
authors.lastname: Hayes
authors.affiliation: Civil & Environmental Engineering Department, University of Michigan, Ann Arbor, Michigan.
authors.forename: Lutgarde
authors.initials: L
authors.lastname: Raskin
mesh_terms: D017738:Alkanesulfonic Acids / Q000494:pharmacology*; D000480:Alkynes / Q000494:pharmacology*; D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002417:Cattle; D019641:DNA, Archaeal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005243:Feces / Q000382:microbiology; D008697:Methane / Q000378:metabolism*; D019640:Methanosarcinales / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D064307:Microbiota / Q000187:drug effects; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D011422:Propionates / Q000494:pharmacology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology
chemical_list: D017738:Alkanesulfonic Acids; D000480:Alkynes; D019641:DNA, Archaeal; D004275:DNA, Ribosomal; D011422:Propionates; D012336:RNA, Ribosomal, 16S; D012722:Sewage; C018853:2-bromoethanesulfonic acid; D010088:Oxidoreductases; C021572:methyl coenzyme M reductase; D008697:Methane; C011537:propiolic acid
keywords: 16S rRNA; 2-bromoethanesulfonate; mcrA; methanogenic inhibitors; propynoic acid.