Kotani Tetsuya, Kawashima Yui, Yurimoto Hiroya, Kato Nobuo, Sakai Yasuyoshi
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Kyoto, Japan.
J Biosci Bioeng. 2006 Sep;102(3):184-92. doi: 10.1263/jbb.102.184.
Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 were isolated from soil samples as propane-utilizing bacteria and were found to be able to utilize various gaseous and liquid n-alkanes as carbon and energy sources. One gene cluster, M-prmABCD, and two gene clusters, P-prm1ABCD and P-prm2ABCD, were cloned from the genomes of Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7, respectively. These gene clusters are homologous to the gene cluster encoding the multicomponent propane monooxygenase (prmABCD) of Gordonia sp. TY-5. The expression of prm gene clusters in Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 was shown to be induced by gaseous n-alkanes (C2-C4) except methane, suggesting that the products of these genes are involved in gaseous n-alkane oxidation. Homologous genes for an alkane hydroxylase system (alk system) involved in liquid n-alkane oxidation were also cloned from the genomic DNA of Mycobacterium sp. TY-6. The alk gene cluster was transcribed in response to liquid n-alkanes (C11-C15). These results indicate that Mycobacterium sp. TY-6 has two distinct gene clusters for multicomponent monooxygenases involved in alkane oxidation. Whole-cell reactions revealed that propane is oxidized to 1-propanol through terminal oxidation in Mycobacterium sp. TY-6 and that propane is oxidized to 1-propanol and 2-propanol through both terminal and subterminal oxidations in Pseudonocardia sp. TY-7. This study reveals the diversity of propane metabolism present in microorganisms.
从土壤样品中分离出分枝杆菌属TY-6菌株和假诺卡氏菌属TY-7菌株，它们作为利用丙烷的细菌，能够利用各种气态和液态正构烷烃作为碳源和能源。分别从分枝杆菌属TY-6菌株和假诺卡氏菌属TY-7菌株的基因组中克隆出一个基因簇M-prmABCD以及两个基因簇P-prm1ABCD和P-prm2ABCD。这些基因簇与戈登氏菌属TY-5中编码多组分丙烷单加氧酶（prmABCD）的基因簇同源。研究表明，除甲烷外，气态正构烷烃（C2-C4）可诱导分枝杆菌属TY-6菌株和假诺卡氏菌属TY-7菌株中prm基因簇的表达，这表明这些基因的产物参与气态正构烷烃的氧化。还从分枝杆菌属TY-6菌株的基因组DNA中克隆出参与液态正构烷烃氧化的烷烃羟化酶系统（alk系统）的同源基因。alk基因簇在液态正构烷烃（C11-C15）的作用下进行转录。这些结果表明，分枝杆菌属TY-6菌株具有两个不同的参与烷烃氧化的多组分单加氧酶基因簇。全细胞反应表明，在分枝杆菌属TY-6菌株中，丙烷通过末端氧化被氧化为1-丙醇；在假诺卡氏菌属TY-7菌株中，丙烷通过末端氧化和亚末端氧化被氧化为1-丙醇和2-丙醇。本研究揭示了微生物中丙烷代谢的多样性。
