Sulfite dehydrogenases in organotrophic bacteria: enzymes, genes and regulation

有机营养细菌中的亚硫酸脱氢酶：酶、基因和调控

• 批准号: 42820529
• 负责人: Professor Dr. Alasdair M. Cook
• 金额: --
• 依托单位: Arbeitsgruppe Mikrobielle Ökologie (aufgelöst)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/42820529?language=en
• 关键词: Sulfite; dehydrogenases; organotrophic; bacteria; enzymes

Sulfite dehydrogenases, which oxidize sulfite to sulfate, are best known within the major fluxes of the sulfur cycle catalyzed during chemolithotrophic and phototrophic growth of e.g. Paracoccus pantotrophus, Starkeya novella and Chlorobium tepidum. Somewhat smaller, organotrophic fluxes of organosulfonates are also part of the sulfur cycle, in which sulfite from the dissimilation of methanesulfonate, dimethylsulfoxide, taurine (and derivatives), sulfolactate and sulfoquinovose, as well as from xenobiotic sources, is oxidized to sulfate. Evidence now indicates that a novel, inducible sulfite dehydrogenase with an unknown native electron acceptor is involved in many organisms. We have established that the enzyme from Cupriavidus necator H16 (previously Ralstonia eutropha), whose genome sequence is available, can be assayed with ferricyanide as the electron acceptor and separated by column chromatography. We will purify and characterize the enzyme, and thus identify the gene and its regulator. Another target is the nature of the native electron acceptor. Strain H16 potentially encodes several orthologues of known sulfite dehydrogenases, whose role in organotrophic metabolism will also be explored.

亚硫酸盐脱氢酶能将亚硫酸盐氧化成硫酸盐，在化学营养和光营养生长过程中所催化的硫循环的主要通量中，亚硫酸盐脱氢酶是最广为人知的。有机磺酸盐的有机营养通量相对较小，也是硫磺循环的一部分，在这个循环中，甲烷磺酸盐、二甲基亚砜、牛磺酸(及其衍生物)、磺酸盐和磺基喹诺糖以及外来来源的亚硫酸盐被氧化成硫酸盐。现在的证据表明，一种新型的、可诱导的亚硫酸盐脱氢酶与许多生物有关，其天然电子受体未知。我们已经建立了以铁氰化物为电子受体，柱层析分离的基因组序列已知的Cupriavidus Necator H16(以前的Ralstonia eutroa)的酶。我们将对该酶进行纯化和鉴定，从而确定该基因及其调控因子。另一个目标是天然电子受体的性质。菌株H16可能编码已知的亚硫酸盐脱氢酶的几个同源物，其在有机营养代谢中的作用也将被探索。