Anaerobic alkane and alkene metabolism in sulfate-reducing prokaryotes

研究得最好的硫酸盐还原菌的烷烃和烯烃降解物种是"Desulfococcus oleovorans"和Desulfatibacillum alkenivorans，其完整的基因组序列是可用的。此外，闪烁古生菌最近被描述为厌氧烷烃和烯烃降解古菌。对于1-烯烃，已提出初始水合成醇，随后氧化成脂肪酸作为初始反应。然而，将烯烃水合为醇的酶的类型是未知的。虽然厌氧烷烃降解在许多生物体中通过将亚末端亚甲基添加到富马酸酯而启动，但"D. "食油动物"不包含任何相应的基因。值得注意的是，"D. oleovorans "und A.然而，萤火虫却编码一种类似钼酶的钼酶，尽管这种生物体并不降解钼。这些基因在D. alkenivorans，其通过富马酸盐加成降解烷烃。最后，这三个基因组都含有类似于乙炔水合物的钨酶基因，这是目前已知的唯一一种将水加到多重键上的酶。我们打算在这个项目中，确定启动厌氧降解烷烃和烯烃的酶的蛋白质组学方法和生物化学方法的天然或重组蛋白质。此外，我们还想从D. oleovorans "或A. fulgidus，独立于它们对烷烃或烯烃的代谢途径的实际贡献。

The best studied alkane- and alkene-degrading species of sulfate-reducing bacteria are Candidatus “Desulfococcus oleovorans” and Desulfatibacillum alkenivorans, for which complete genome sequences are available. In addition, Archaeoglobus fulgidus was recently described as anaerobic alkane- and alkene-degrading archaeon. For 1-alkenes, an initial hydration to alcohols with subsequent oxidation to fatty acids has been proposed as initial reaction. However, the type of enzyme hydratising alkenes to alcohols is unknown. While anaerobic alkane degradation is initiated in many organisms by addition of the subterminal methylene group to fumarate, the genome of “D. oleovorans” does not contain any of the corresponding genes. It is remarkable that the genomes of “D. oleovorans” und A. fulgidus instead code for an ethylbenzene dehydrogenase-like molybdenum enzyme, although the organisms does not degrade ethylbenzene. These genes are lacking in the genome of D. alkenivorans, which degrades alkanes via fumarate addition. Finally, all three genomes contain genes for molybdo- or tungsto-enzymes similar to acetylene hydrates, the only currently known enzyme adding water to a multiple bond. We intend in this project to identify the enzymes initiating the anaerobic degradation of alkanes and alkenes by proteomic approaches and characterise the native or recombinant proteins by biochemical methods. In addition, we want to characterise the paralogs of ethylbenzene dehydrogenase and acetylene hydratase from “D. oleovorans” or A. fulgidus, independently of their actual contributions to the metabolic pathway of alkanes or alkenes.