Genes involved in alkane degradation in the Alcanivorax hongdengensis strain A-11-3.
Alcanivorax hongdengensis A-11-3 is a newly identified type strain isolated from the surface water of the Malacca and Singapore Straits that can degrade a wide range of alkanes. To understand the degradation mechanism of this strain, the genes encoding alkane hydroxylases were obtained by PCR screening and shotgun sequencing of a genomic fosmid library. Six genes involved in alkane degradation were found, including alkB1, alkB2, p450-1, p450-2, p450-3 and almA. Heterogeneous expression analysis confirmed their functions as alkane oxidases in Pseudomonas putida GPo12 (pGEc47ΔB) or Pseudomonas fluorescens KOB2Δ1. Q-PCR revealed that the transcription of alkB1 and alkB2 was enhanced in the presence of n-alkanes C(12) to C(24); three p450 genes were up-regulated by C(8)-C(16)                         n-alkanes at different levels, whereas enhanced expression of almA was observed when strain A-11-3 grew with long-chain alkanes (C(24) to C(36)). In the case of branched alkanes, pristane significantly enhanced the expression of alkB1, p450-3 and almA. The six genes enable strain A-11-3 to degrade short (C(8)) to long (C(36)) alkanes that are straight or branched. The ability of A. hongdengensis A-11-3 to thrive in oil-polluted marine environments may be due to this strain's multiple systems for alkane degradation and its range of substrates.
The Third Institute of Oceanography, State Oceanic Administration, Xiamen, China. wangwanpeng2008@126.com
Wanpeng
W
Wang
Zongze
Z
Shao
D053521:Alcanivoraceae / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000473:Alkanes / Q000378:metabolism*; D001711:Biotransformation; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011551:Pseudomonas fluorescens / Q000235:genetics; D016958:Pseudomonas putida / Q000235:genetics; D012623:Seawater / Q000382:microbiology; D017422:Sequence Analysis, DNA; D012846:Singapore
D000473:Alkanes; D004269:DNA, Bacterial