Sequencing and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) Analysis of Four Hydrogenase Gene Clusters from an Obligately Autotrophic Hydrogen-Oxidizing Bacterium,Hydrogenobacter thermophilus TK-6

摘要

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%.