甲酸鹽被氧化為二氧化碳和氫的反應(yīng)是厭氧環(huán)境中微生物的一種常見反應(yīng),，但它釋放的能量很少,，而且過去也沒有發(fā)現(xiàn)它能在某個孤立物種中維持生長。但現(xiàn)在,，Kim等人發(fā)現(xiàn),，Thermococcus屬的幾種“超嗜熱古細菌”的確能夠利用甲酸鹽氧化來生長。
這些生物生活在80°C以上的環(huán)境中,，相對于那些利用迄今所介紹過的最簡單厭氧呼吸形式之一的生物來說，這樣一種生活環(huán)境可能會給它們提供一個競爭優(yōu)勢,。
生物谷推薦原文出處：
Nature doi:10.1038/nature09375
Formate-driven growth coupled with H2 production
Yun Jae Kim,Hyun Sook Lee,Eun Sook Kim,Seung Seob Bae,Jae Kyu Lim,Rie Matsumi,Alexander V. Lebedinsky,Tatyana G. Sokolova,Darya A. Kozhevnikova,Sun-Shin Cha,Sang-Jin Kim,Kae Kyoung Kwon,Tadayuki Imanaka,Haruyuki Atomi,Elizaveta A. Bonch-Osmolovskaya,Jung-Hyun ,Sung Gyun Kang
Although a common reaction in anaerobic environments, the conversion of formate and water to bicarbonate and H2 (with a change in Gibbs free energy of ΔG° = +1.3?kJ?mol?1) has not been considered energetic enough to support growth of microorganisms. Recently, experimental evidence for growth on formate was reported for syntrophic communities of Moorella sp. strain AMP and a hydrogen-consuming Methanothermobacter species and of Desulfovibrio sp. strain G11 and Methanobrevibacter arboriphilus strain AZ1. The basis of the sustainable growth of the formate-users is explained by H2 consumption by the methanogens, which lowers the H2 partial pressure, thus making the pathway exergonic2. However, it has not been shown that a single strain can grow on formate by catalysing its conversion to bicarbonate and H2. Here we report that several hyperthermophilic archaea belonging to the Thermococcus genus are capable of formate-oxidizing, H2-producing growth. The actual ΔG values for the formate metabolism are calculated to range between ?8 and ?20?kJ?mol?1 under the physiological conditions where Thermococcus onnurineus strain NA1 are grown. Furthermore, we detected ATP synthesis in the presence of formate as a sole energy source. Gene expression profiling and disruption identified the gene cluster encoding formate hydrogen lyase, cation/proton antiporter and formate transporter, which were responsible for the growth of T. onnurineus NA1 on formate. This work shows formate-driven growth by a single microorganism with protons as the electron acceptor, and reports the biochemical basis of this ability.
