title: Effects of increasing organic loading rate on performance and microbial community shift of an up-flow anaerobic sludge blanket reactor treating diluted pharmaceutical wastewater.
abstract: The performance of an up-flow anaerobic sludge blanket (UASB) reactor was investigated in the treatment of diluted pharmaceutical fermentation wastewater for a continuous operation of 140 days. The dynamics and compositions of the microbial community were monitored using polymerase chain reaction (PCR)-restriction fragment length polymorphism (PCR-RFLP) analysis. Increase of the organic loading rate (OLR) from 2.7 kg COD/m(3) d to 7.2 COD/m(3) d led to an increase in the COD removal efficiency from 83% to 91%. The dominant bacteria shifted from Proteobacteria (23.8%), Chloroflexi (14.5%) and Firmicutes (4.0%) to Firmicutes (48.4%), Bacteroidetes (9.5%) and Proteobacteria (5.4%). For archeaon, the dominant groups changed from Thermoplasmata (24.4%), Thermoprotei (18.0%) and Methanobacteria (30.8%) to Thermoplasmata (70.4%) and Methanomicrobia (16.8%). Firmicutes, Bacteroidetes, Thermoplasmata and Methanobacteria could outcompete other species and dominated in the reactor under higher OLR. The results indicated that, to some extent, microbial community shift could reflect the performance of the reactor and a significant community shift corresponded to a considerable process event.
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China. Electronic address: zhouhb@mail.csu.edu.cn.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhou
mesh_terms: D000641:Ammonia / Q000378:metabolism / Q000494:pharmacology*; D000693:Anaerobiosis; D001105:Archaea / Q000145:classification / Q000187:drug effects* / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000378:metabolism; D019149:Bioreactors; D004345:Drug Industry; D059013:Microbial Consortia / Q000187:drug effects* / Q000502:physiology; D009584:Nitrogen / Q000378:metabolism / Q000494:pharmacology*; D010802:Phylogeny; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000382:microbiology*
chemical_list: D000641:Ammonia; D009584:Nitrogen; D062065:Wastewater
keywords: Anaerobic digestion; Microbial community; Pharmaceutical fermentation wastewater; Polymerase chain reaction-restriction fragment length polymorphism; Up-flow anaerobic sludge blanket