Ueda Yasufumi, Yamamoto Masahiro, Urasaki Takashi, Arai Hiroyuki, Ishii Masaharu, Igarashi Yasuo
Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
J Biosci Bioeng. 2007 Dec;104(6):470-5. doi: 10.1263/jbb.104.470.
A thermophilic, chemolithoautotrophic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus TK-6, fixes carbon dioxide via the reductive tricarboxylic acid cycle and grows rapidly with a generation time of about 1 h. TK-6 is believed to have an efficient hydrogen-oxidizing ability to support such rapid growth. We cloned hydrogenase genes from TK-6 and found that this strain has at least four clusters of hydrogenase genes. Reverse transcription-polymerase chain reaction (RT-PCR) analyses showed that all four hydrogenase gene clusters were transcribed under aerobic condition at hydrogen concentrations of 45% and 60%. One of them was not transcribed at a hydrogen concentration of 20%. All the four hydrogenase gene clusters were expressed under anaerobic denitrifying condition at a hydrogen concentration of 75%.
嗜热栖热氢杆菌TK-6是一种嗜热、化能无机自养型氢氧化细菌，它通过还原性三羧酸循环固定二氧化碳，且生长迅速，代时约为1小时。据信，TK-6具有高效的氢氧化能力以支持这种快速生长。我们从TK-6中克隆了氢化酶基因，发现该菌株至少有四个氢化酶基因簇。逆转录聚合酶链反应（RT-PCR）分析表明，在有氧条件下，氢气浓度为45%和60%时，所有四个氢化酶基因簇均被转录。其中一个在氢气浓度为20%时未被转录。在厌氧反硝化条件下，氢气浓度为75%时，所有四个氢化酶基因簇均有表达。
