a Department of Microbiology , Montana State University , Bozeman , MT , USA.
Biofouling. 2000;15(1-3):13-23. doi: 10.1080/08927010009386294.
Pit propagation in carbon steel exposed to a phosphate-containing electrolyte required either stagnant conditions or microbial colonization of anodic regions. A scanning vibrating electrode (SVE) was used to resolve formation and inactivation of anodic and cathodic sites on carbon steel. In sterile, continuously aerated medium, pits initiated and repassivated, while in the absence of aeration, pits initiated and propagated. Pit propagation was also observed in continuously aerated medium inoculated with a heterotrophic bacterium, originally isolated from a corrosion tubercle formed on a steel pipe in a fresh water environment. Autoradiography of bacteria following uptake of (14)C-acetate into cellular material in combination with SVE analysis demonstrated that sites of anodic activity coincided with sites of bacterial activity. Prelabeled bacteria also preferentially attached to corrosion products over the anodic sites. Confocal laser scanning microscopy demonstrated that attraction to anodic sites did not depend on bacterial viability and was not specific for iron as a substratum. The results suggest that bacteria may preferentially attach to the corrosion products formed over corrosion pits. The biofilms over these anodic sites may create stagnant conditions within corrosion pits that result in pit propagation.
在含有磷酸盐的电解质中，碳钢的晶间腐蚀需要停滞的条件或阳极区域的微生物定殖。扫描振动电极（SVE）用于解析碳钢阳极和阴极位置的形成和失活。在无菌、连续充气的培养基中，孔穴会启动并重新钝化，而在不充气的情况下，孔穴会启动并扩展。在连续充气的培养基中接种了一种异养细菌，该细菌最初是从淡水环境中钢质管道上形成的腐蚀瘤中分离出来的，也观察到了孔穴的扩展。将（14）C-乙酸摄取到细胞物质中后对细菌进行放射性自显影，并结合 SVE 分析，结果表明阳极活性位点与细菌活性位点一致。预标记的细菌也优先附着在腐蚀产物上而不是阳极上。共焦激光扫描显微镜表明，对阳极位点的吸引力不依赖于细菌的活力，并且对铁作为基质没有特异性。结果表明，细菌可能优先附着在腐蚀坑上形成的腐蚀产物上。这些阳极位置上的生物膜可能会在腐蚀坑内产生停滞的条件，从而导致坑的扩展。
