School of Ocean, Yantai University, Yantai, 264005, China.
School of Civil Engineering, Yantai University, Yantai, 264005, China.
Sci Rep. 2020 Apr 1;10(1):5744. doi: 10.1038/s41598-020-62809-y.
Bacillus widely exists in wet natural environment such as soil, water and air, and is often studied as one of representative microorganisms for microbiologically influenced corrosion(MIC) research. In this paper, the growth curve of Bacillus subtilis isolated from marine environment was determined by turbidimetry and its effect on corrosion behavior of 10MnNiCrCu steel was studied by open circuit potential, AC impedance, polarization curve and scanning electron microscopy(SEM). The results showed that with the change of the growth curve of Bacillus subtilis(BS), the open circuit potential(E) shifted positively and then negatively, and the charge transfer resistance shown by AC impedance was much lower than that of the sterile system, increasing first and then decreasing. The polarization curves showed that the corrosion current density in BS medium was obviously higher than that in sterile system. The corrosion morphology observation showed that although a biofilm by BS developed on the steel surface, the localized corrosion of 10MnNiCrCu steel was aggravated due to the acidness of the metabolite itself and the biofilm with access for electrolyte ions.
芽孢杆菌广泛存在于土壤、水和空气等湿润的自然环境中，常被作为微生物影响腐蚀（MIC）研究的代表性微生物之一进行研究。本文通过比浊法测定了从海洋环境中分离出的枯草芽孢杆菌的生长曲线，并通过开路电位、交流阻抗、极化曲线和扫描电子显微镜（SEM）研究了其对 10MnNiCrCu 钢腐蚀行为的影响。结果表明，随着枯草芽孢杆菌（BS）生长曲线的变化，开路电位（E）先正移后负移，交流阻抗显示的电荷转移电阻远低于无菌体系，先升高后降低。极化曲线表明，BS 介质中的腐蚀电流密度明显高于无菌体系。腐蚀形貌观察表明，虽然 BS 在钢表面形成了生物膜，但由于代谢物本身的酸性以及生物膜与电解质离子的连通性，10MnNiCrCu 钢的局部腐蚀加剧。
