title: Effects of 1,1,1-trichloroethane on enzymatic activity and bacterial community in anaerobic microcosm form sequencing batch reactors.
abstract: 1,1,1-Trichloroethane (TCA), a major organic and groundwater contaminant, has very strong toxic effects on humans, plants and microorganisms. Effects of TCA on enzymatic activity and microbial diversity were investigated in the anaerobic sequencing batch reactor (ASBR) under methanogenic, nitrate-reducing, sulfate-reducing and benzene/toluene degrading conditions. The activities of three enzymes (lactate dehydrogenase, phosphatase and protease) were significantly decreased in the presence of 5 mg/L TCA. Within these three affected enzymes, phosphatase activity may serve as a noteworthy marker of bacterial toxicity. The activity of phosphatase was 0.2 U/L in methanogenic conditions with 5 mg/L TCA, which was 99% lower than the controls, and the enzyme activity was 18.6 U/L in methanogenic conditions with 1 mg/L TCA, which was 7% lower than the controls. DGGE profiles showed that TCA altered the bacterial community distribution and diversity obviously during the 21 day of TCA exposure. The enzyme activities decreased second lowest but TCA degrading strains Clostridium sp. DhR-2/LM-G01, Bacterial clone DCE25 and Bacterial clone DPHB06 were enriched in the methanogenic ASBR amended TCA.
authors.affiliation: Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.forename: Yong-Di
authors.initials: YD
authors.lastname: Liu
authors.forename: Kuang-Fei
authors.initials: KF
authors.lastname: Lin
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Lu
authors.forename: Bo-Zhong
authors.initials: BZ
authors.lastname: Mu
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Du
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lu
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Shen
authors.forename: Bing-Zhi
authors.initials: BZ
authors.lastname: Li
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Zhao
authors.forename: Yang-Yang
authors.initials: YY
authors.lastname: Li
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000187:drug effects* / Q000201:enzymology; D001673:Biodegradation, Environmental / Q000187:drug effects; D019149:Bioreactors / Q000382:microbiology*; D004269:DNA, Bacterial / Q000302:isolation & purification; D004784:Environmental Monitoring / Q000379:methods*; D060587:Groundwater / Q000737:chemistry / Q000382:microbiology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008697:Methane / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010802:Phylogeny; D014240:Trichloroethanes / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D004269:DNA, Bacterial; D014240:Trichloroethanes; D014874:Water Pollutants, Chemical; C024566:1,1,1-trichloroethane; D007770:L-Lactate Dehydrogenase; D010744:Phosphoric Monoester Hydrolases; D010447:Peptide Hydrolases; D008697:Methane