title: A comparative genomics and reductive dehalogenase gene transcription study of two chloroethene-respiring bacteria, Dehalococcoides mccartyi strains MB and 11a.
abstract: Genomes of two trichloroethene (TCE)-respiring Dehalococcoides (Dhc) mccartyi, strains MB and 11a, were sequenced to identify reductive dehalogenases (RDase) responsible for oraganohalide respiration. Transcription analyses were conducted to verify the roles of RDase subunit A genes (rdhA) in chloroethene respiration. Some interesting features of the strain MB draft genome include a large genome size, two CRISPR-cas type I systems, and 38 rdhA genes. Strain 11a has a stream-lined genome with 11 rdhA genes, of which nine are distinct. Quantitative real-time PCR transcription analysis of RDase gene transcripts showed that a single RDase gene, designated mbrA, was up-regulated upon exposure to TCE and no other RDase genes were considerably expressed in strain MB. A single RDase gene, designated vcrA, was up-regulated upon exposure to TCE and expressed at a steady level until all chloroethenes were completely dechlorinated to ethene at 147 h in strain 11a. Overall, this study reports the genomes of two distinct Dhc strains; both contain numerous uncharacterized RDase genes, but in each strain only one such gene was expressed highly during organohalide respiration.
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576.
authors.forename: Adrian
authors.initials: A
authors.lastname: Low
authors.affiliation: B5423-AC1, School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576.
authors.forename: Dan
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Rogers
authors.affiliation: B5423-AC1, School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Patrick K H
authors.initials: PK
authors.lastname: Lee
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: He
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D016680:Genome, Bacterial / Q000235:genetics*; D023281:Genomics / Q000379:methods; D054879:Halogenation / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics*; D014241:Trichloroethylene / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D014241:Trichloroethylene