title: Dynamic transition of microbial communities in response to acidification in fixed-bed anaerobic baffled reactors (FABR) of two different flow directions.
abstract: Two five-compartment fixed-bed anaerobic baffled reactors (FABRs) were operated under deteriorative and stable conditions. The FABRs were identical except for flow direction: one was horizontal (H-reactor) and the other was vertical (V-reactor). The microbial community dynamics in 1, 3 and 5 compartments were analyzed using denaturing gradient gel electrophoresis (DGGE), 16S rRNA gene clone library screening and quantitative PCR. After start-up, the Methanomicrobiales were typically dominant in adhering sludge of 5th compartments of two reactors. Because methanogenesis mainly occurred in the latter compartment, Methanomicrobiales were likely to play important roles in FABRs. FABRs recovered from performance deterioration very quickly. Meanwhile, methanogens and dominant methanogens greatly increased in every compartment of two reactors. Our results indicated that 16S rRNA levels of methanogens in the adhering sludge were higher than those in the deposited sludge and the adhering fraction of V-reactor held up more acid-resistant bacteria and methanogens than that of H-reactor.
authors.affiliation: College of Agronomy and Biotechnology/Center of Biomass Engineering, China Agricultural University, Beijing 100193, China.
authors.forename: Dongdong
authors.initials: D
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Guo
authors.forename: Peipei
authors.initials: P
authors.lastname: Li
authors.forename: Yali
authors.initials: Y
authors.lastname: Suo
authors.forename: Xiaofen
authors.initials: X
authors.lastname: Wang
authors.forename: Zongjun
authors.initials: Z
authors.lastname: Cui
mesh_terms: D018441:Biofilms; D019149:Bioreactors; D016000:Cluster Analysis; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D017753:Ecosystem; D008697:Methane / Q000096:biosynthesis*; D017018:Methanomicrobiales / Q000235:genetics*; D010802:Phylogeny; D011157:Population Dynamics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D017931:DNA Primers; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D008697:Methane