title: Molecular characterization of the alkB gene in the thermophilic Geobacillus sp. strain MH-1.
abstract: An extremely thermophilic alkane-degrading bacterium, strain MH-1, was isolated from the deep subterranean petroleum reservoir in Shengli oil field, PR China. Based on its physiological characteristics and analysis of its 16S rRNA gene sequence, strain MH-1 was identified as Geobacillus stearothermophilus. Strain MH-1 was able to grow at temperatures ranging from 50 to 72 degrees C and effectively degraded hexadecane as the sole carbon source at 70 degrees C. Strain MH-1 degraded alkanes with different length chains (C(12)-C(31)) in crude oil, but it preferentially degraded middle chain-alkanes. The alkane hydroxylase system of G. stearothermophilus MH-1 was characterized. It contained at least three alkane monooxygenase gene homologs (alkB-geo1, alkB-geo4, and alkB-geo6). The AlkB-geo6 cluster, which had a high sequence similarity to the alkB2 cluster of Rhodococcus strains NRRL B-16531 and Q15, contained alkB-geo6, two rubredoxins and a putative transcriptional regulatory protein.
authors.affiliation: Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Liu
authors.forename: Tian-Tian
authors.initials: TT
authors.lastname: Zhou
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Lian
authors.initials: L
authors.lastname: Xu
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Qi-Rong
authors.initials: QR
authors.lastname: Shen
authors.forename: Biao
authors.initials: B
authors.lastname: Shen
mesh_terms: D000473:Alkanes / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics*; D002681:China; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005798:Genes, Bacterial; D056506:Geobacillus / Q000145:classification* / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D006358:Hot Temperature; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D000473:Alkanes; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C007932:n-hexadecane