Gene diversity of CYP153A and AlkB alkane hydroxylases in oil-degrading bacteria isolated from the Atlantic Ocean
Gene diversity of CYP153A and AlkB alkane hydroxylases in oil-degrading bacteria isolated from the Atlantic Ocean
复制标题
大西洋分离的石油降解细菌中 CYP153A 和 AlkB 烷烃羟化酶的基因多样性
DOI：
10.1111/j.1462-2920.2010.02165.x
复制
发表时间：
2010-05-01
影响因子：
5.1
通讯作者：
Shao, Zongze
中科院分区：
文献类型：
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作者：
Wang, Liping;Wang, Wanpeng;Shao, Zongze
烷烃羟化酶，包括整膜非血红素铁单加氧酶（AlkB）和细胞色素P450 CYP153家族，是细菌烷烃氧化的关键酶。虽然这两个基因已经在许多细菌和环境中被检测到，但关于海洋烷烃降解细菌中这些基因的多样性的知识仍然有限，特别是在远洋地区。本研究从大西洋表层海水样品富集的18个油降解菌群中分离得到177株细菌，共43属。许多分离菌株被证实是其所属属的第一个油降解菌，包括Brachybacterium、Idiomarina、Leifsonia、Martelella、Kordiimonas、Parvibaculum和Tistrella。利用退化PCR引物，对这些细菌的alkB和CYP153A P450基因进行了检测。从80株分离株中共分离得到82个P450和52个alkB基因片段。这些菌株主要属于Alcanivorax、Bacillus、Erythrobacter、Martelella、Parvibaculum和Salinisphaera，其中一些菌株为首次报道编码烷烃羟化酶。系统发育分析表明，这两个基因具有相当大的多样性，并形成了多个簇，其中大部分来自各种Alcanivorax细菌。值得注意的是，一些序列，例如来自Salinisphaera属的序列，被归为一个远亲的新集群。基因与宿主的连锁关系分析表明，alkB和P450在Alcanivorax和Salinisphaera中倾向于共存，而在Parvibaculum的所有分离株中均只发现P450基因，但有多个同源基因。alkB的多个同源物大多同时存在于木樨状菌分离株中。相反，远亲分离株含有相似甚至相同的序列。综上所述，在大西洋地表水中发现了多种携带多种P450和alkB基因的石油降解细菌。我们的研究结果有助于揭示P450和alkB基因在原核生物中的多样性，并描绘海洋环境中石油降解细菌的地理分布。
P>Alkane hydroxylases, including the integral-membrane non-haem iron monooxygenase (AlkB) and cytochrome P450 CYP153 family, are key enzymes in bacterial alkane oxidation. Although both genes have been detected in a number of bacteria and environments, knowledge about the diversity of these genes in marine alkane-degrading bacteria is still limited, especially in pelagic areas. In this report, 177 bacterial isolates, comprising 43 genera, were obtained from 18 oil-degrading consortia enriched from surface seawater samples collected from the Atlantic Ocean. Many isolates were confirmed to be the first oil-degraders in their affiliated genera including Brachybacterium, Idiomarina, Leifsonia, Martelella, Kordiimonas, Parvibaculum and Tistrella. Using degenerate PCR primers, alkB and CYP153A P450 genes were surveyed in these bacteria. In total, 82 P450 and 52 alkB gene fragments were obtained from 80 of the isolates. These isolates mainly belonged to Alcanivorax, Bacillus, Erythrobacter, Martelella, Parvibaculum and Salinisphaera, some of which were reported, for the first time, to encode alkane hydroxylases. Phylogenetic analysis showed that both genes were quite diverse and formed several clusters, most of which were generated from various Alcanivorax bacteria. Noticeably, some sequences, such as those from the Salinisphaera genus, were grouped into a distantly related novel cluster. Inspection of the linkage between gene and host revealed that alkB and P450 tend to coexist in Alcanivorax and Salinisphaera, while in all isolates of Parvibaculum, only P450 genes were found, but of multiple homologues. Multiple homologues of alkB mostly cooccurred in Alcanivorax isolates. Conversely, distantly related isolates contained similar or even identical sequences. In summary, various oil-degrading bacteria, which harboured diverse P450 and alkB genes, were found in the surface water of Atlantic Ocean. Our results help to show the diversity of P450 and alkB genes in prokaryotes, and to portray the geographic distribution of oil-degrading bacteria in marine environments.