Henstra Anne M, Dijkema Cor, Stams Alfons J M
Laboratory of Microbiology, Wageningen University, H. v. Suchtelenweg 4, 6703 CT, Wageningen, The Netherlands.
Environ Microbiol. 2007 Jul;9(7):1836-41. doi: 10.1111/j.1462-2920.2007.01306.x.
The genome sequence of Archaeoglobus fulgidus VC16 encodes three CO dehydrogenase genes. Here we explore the capacity of A. fulgidus to use CO as growth substrate. Archaeoglobus fulgidus VC16 was successfully adapted to growth medium that contained sulfate and CO. In the presence of CO and sulfate the culture OD(660) increased to 0.41 and sulfide, carbon dioxide, acetate and formate were formed. Accumulation of formate was transient. Similar results, except that no sulfide was formed, were obtained when sulfate was omitted. Hydrogen was never detected. Under the conditions tested, the observed concentrations of acetate (18 mM) and formate (8.2 mM) were highest in cultures without sulfate. Proton NMR spectroscopy indicated that CO2, and not CO, is the precursor of formate and the methyl group of acetate. Methylviologen-dependent formate dehydrogenase activity (1.4 micromol formate oxidized min(-1) mg(-1)) was detected in cell-free extracts and expected to have a role in formate reuptake. It is speculated that formate formation proceeds through hydrolysis of formyl-methanofuran or formyl-tetrahydromethanopterin. This study demonstrates that A. fulgidus can grow chemolithoautotrophically with CO as acetogen, and is not strictly dependent on the presence of sulfate, thiosulfate or other sulfur compounds as electron acceptor.
嗜热栖热古菌VC16的基因组序列编码三个一氧化碳脱氢酶基因。在此，我们探究了嗜热栖热古菌利用一氧化碳作为生长底物的能力。嗜热栖热古菌VC16成功适应了含有硫酸盐和一氧化碳的生长培养基。在一氧化碳和硫酸盐存在的情况下，培养物的OD(660)增加到0.41，并且形成了硫化物、二氧化碳、乙酸盐和甲酸盐。甲酸盐的积累是短暂的。当省略硫酸盐时，得到了类似的结果，只是没有形成硫化物。从未检测到氢气。在所测试的条件下，在不含硫酸盐的培养物中观察到的乙酸盐（18 mM）和甲酸盐（8.2 mM）浓度最高。质子核磁共振光谱表明，二氧化碳而非一氧化碳是甲酸盐和乙酸盐甲基的前体。在无细胞提取物中检测到依赖甲基紫精的甲酸盐脱氢酶活性（1.4微摩尔甲酸盐氧化分钟(-1)毫克(-1)），预计其在甲酸盐再摄取中起作用。据推测，甲酸盐的形成是通过甲酰基-甲烷呋喃或甲酰基-四氢甲烷蝶呤的水解进行的。这项研究表明，嗜热栖热古菌可以以一氧化碳作为产乙酸菌进行化能自养生长，并且不严格依赖于硫酸盐、硫代硫酸盐或其他硫化合物作为电子受体的存在。
