Hydrogen as an energy source for the human pathogen Bilophila wadsworthia
Hydrogen as an energy source for the human pathogen Bilophila wadsworthia
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DOI：
10.1007/s10482-007-9215-x
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发表时间：
2008-05-01
影响因子：
2.6
通讯作者：
Pereira, Ines A. C.
中科院分区：
文献类型：
--
作者：
da Silva, Sofia M.;Venceslau, Sofia S.;Pereira, Ines A. C.
革兰氏阴性厌氧肠道细菌Bilophila wadsaccharia是穿孔性和坏疽性阑尾炎中第三常见的分离株，也在各种其他感染中发现。这种生物体进行一种独特的无氧呼吸，其中牛磺酸，哺乳动物中的主要有机溶质，被用作亚硫酸盐的来源，亚硫酸盐作为电子传递链的末端受体。我们在这里表明，分子氢，在结肠中的发酵细菌的主要产品之一，是一个很好的生长基质B。wadsobiria。我们已经量化了与H-2，甲酸和丙酮酸的氧化在不同的生长条件下获得的细胞的酶活性。细胞提取物呈现高水平的氢化酶活性，并且该生物体可以表达多达五种不同的氢化酶。其中一种氢化酶似乎是组成型的，而其他的在不同的生长条件下表现出差异表达。其中两种氢化酶是可溶性的，并被抗硫酸盐还原菌[FeFe]氢化酶的抗体识别。其中一种氢化酶在丙酮酸发酵生长过程中被特异性诱导。另外两种氢化酶是膜结合的，并且在用氢生长的细胞中显示出增加的表达。进一步的工作应该进行，以揭示是否氢的氧化有助于毒性的B。wadsobiria。
The gram-negative anaerobic gut bacterium Bilophila wadsworthia is the third most common isolate in perforated and gangrenous appendicitis, being also found in a variety of other infections. This organism performs a unique kind of anaerobic respiration in which taurine, a major organic solute in mammals, is used as a source of sulphite that serves as terminal acceptor for the electron transport chain. We show here that molecular hydrogen, one of the major products of fermentative bacteria in the colon, is an excellent growth substrate for B. wadsworthia. We have quantified the enzymatic activities associated with the oxidation of H-2, formate and pyruvate for cells obtained in different growth conditions. The cell extracts present high levels of hydrogenase activity, and up to five different hydrogenases can be expressed by this organism. One of the hydrogenases appears to be constitutive, whereas the others show differential expression in different growth conditions. Two of the hydrogenases are soluble and are recognised by antibodies against a [FeFe] hydrogenase of a sulphate reducing bacterium. One of these hydrogenases is specifically induced during fermentative growth on pyruvate. Another two hydrogenases are membrane-bound and show increased expression in cells grown with hydrogen. Further work should be carried out to reveal whether oxidation of hydrogen contributes to the virulence of B. wadsworthia.