Department of Chemistry, University of Gothenburg, Göteborg, Sweden.
FEMS Microbiol Lett. 2009 Aug;297(1):87-94. doi: 10.1111/j.1574-6968.2009.01677.x. Epub 2009 Jun 3.
Bacteria performing anaerobic ammonium oxidation (anammox) are key players in the global nitrogen cycle due to their inherent ability to convert biologically available nitrogen to N(2). Anammox is increasingly being exploited during wastewater treatment worldwide, and about 50% of the total N(2) production in marine environments is estimated to proceed by the anammox pathway. To fully understand the microbial functionality and mechanisms that control environmental feedbacks of the anammox reaction, key proteins involved in the reaction must be identified. In this study we have utilized an analytical protocol that facilitates detection of proteins associated with the anammoxosome, an intracellular membrane compartment within the anammox bacterium. The protocol enabled us to identify several key proteins of the anammox reaction including a hydrazine hydrolase producing hydrazine, a hydrazine-oxidizing enzyme converting hydrazine to N(2) and a membrane-bound ATP synthase generating ATP from the gradients of protons formed in the anammox reaction. We also performed immunogold labelling electron microscopy to determine the subcellular location of the hydrazine hydrolase. The results from our study support the hypothesis that proteins associated with the anammoxosome host the complete suite of reactions during anammox.
进行厌氧氨氧化（anammox）的细菌是全球氮循环中的关键参与者，因为它们具有将生物可利用的氮转化为 N(2)的固有能力。anammox 越来越多地在全球范围内被用于废水处理，并且估计海洋环境中大约 50%的总 N(2)产生是通过 anammox 途径进行的。为了充分了解控制 anammox 反应环境反馈的微生物功能和机制，必须确定参与反应的关键蛋白质。在这项研究中，我们利用了一种分析方案，该方案有助于检测与 anammoxosome 相关的蛋白质，anammoxosome 是 anammox 细菌内的一种细胞内膜隔室。该方案使我们能够鉴定出 anammox 反应的几种关键蛋白质，包括产生肼的肼水解酶、将肼转化为 N(2)的肼氧化酶以及利用 anammox 反应中形成的质子梯度从 ATP 合成酶生成 ATP 的膜结合型 ATP 合成酶。我们还进行了免疫金标记电子显微镜检查，以确定肼水解酶的亚细胞位置。我们的研究结果支持了这样一种假设，即与 anammoxosome 相关的蛋白质承载了 anammox 过程中的完整反应系列。
