Abstract:
Corrosion of iron-containing metals under sulfate-reducing conditions is an economically important problem. Microbial strains now known as Desulfovibrio vulgaris served as the model microbes in many of the foundational studies that developed existing models for the corrosion of iron-containing metals under sulfate-reducing conditions. Proposed mechanisms for corrosion by D. vulgaris include: (1) H2 consumption to accelerate the oxidation of Fe0 coupled to the reduction of protons to H2; (2) production of sulfide that combines with ferrous iron to form iron sulfide coatings that promote H2 production; (3) moribund cells release hydrogenases that catalyze Fe0 oxidation with the production of H2; (4) direct electron transfer from Fe0 to cells; and (5) flavins serving as an electron shuttle for electron transfer between Fe0 and cells. The demonstrated possibility of conducting transcriptomic and proteomic analysis of cells growing on metal surfaces suggests that similar studies on D. vulgaris corrosion biofilms can aid in identifying proteins that play an important role in corrosion. Tools for making targeted gene deletions in D. vulgaris are available for functional genetic studies. These approaches, coupled with instrumentation for the detection of low concentrations of H2, and proven techniques for evaluating putative electron shuttle function, are expected to make it possible to determine which of the proposed mechanisms for D. vulgaris corrosion are most important.
摘要:
含铁金属在硫酸盐还原条件下的腐蚀是经济上重要的问题。在许多基础研究中,现在称为普通脱硫弧菌的微生物菌株用作模型微生物,这些基础研究开发了在硫酸盐还原条件下含铁金属腐蚀的现有模型。提出的普通D.的腐蚀机理包括:(1)消耗H2以加速Fe0的氧化,并将质子还原为H2;(2)与亚铁结合形成促进H2产生的硫化铁涂层的硫化物的产生;(3)垂死的细胞释放氢化酶,催化Fe0氧化并产生H2;(4)从Fe0到细胞的直接电子转移;(5)黄素作为电子在Fecells和电子之间转移电子0。对金属表面上生长的细胞进行转录组学和蛋白质组学分析的证明可能性表明,对普通D.vulgaris腐蚀生物膜的类似研究可以帮助鉴定在腐蚀中起重要作用的蛋白质。在普通D.中进行靶向基因缺失的工具可用于功能遗传研究。这些方法,加上用于检测低浓度H2的仪器,以及用于评估假定的电子穿梭功能的成熟技术,预计将有可能确定哪种拟议的寻常D.vulgaris腐蚀机理是最重要的。