Ilhan-Sungur Esra, Ozuolmez Derya, Çotuk Ayşın, Cansever Nurhan, Muyzer Gerard
Department of Biology, Istanbul University, 34134, Vezneciler, Istanbul, Turkey.
Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
Anaerobe. 2017 Feb;43:27-34. doi: 10.1016/j.anaerobe.2016.11.005. Epub 2016 Nov 18.
Sulfidogenic Clostridia and sulfate reducing bacteria (SRB) often cohabit in nature. The presence of these microorganisms can cause microbially influenced corrosion (MIC) of materials in different ways. To investigate this aspect, bacteria were isolated from cooling tower water and used in corrosion tests of galvanized steel. The identity of the isolates was determined by comparative sequence analysis of PCR-amplified 16S rDNA gene fragments, separated by denaturing gradient gel electrophoresis (DGGE). This analysis showed that, in spite of the isolation process, colonies were not pure and consisted of a mixture of bacteria affiliated with Desulfosporosinus meridiei and Clostridium sp. To evaluate the corrosive effect, galvanized steel coupons were incubated with a mixed culture for 4, 8, 24, 72, 96, 168, 360 and 744 h, along with a control set in sterile culture medium only. The corrosion rate was determined by weight loss, and biofilm formation and corroded surfaces were observed by scanning electron microscopy (SEM). Although the sulfide-producing bacterial consortium led to a slight increase in the corrosion of galvanized steel coupons, when compared to the previous studies it can be said that Clostridium sp. can reduce the corrosive effect of the Desulfosporosinus sp. strain.
产硫化物的梭状芽孢杆菌和硫酸盐还原菌（SRB）在自然界中常常共同存在。这些微生物的存在会以不同方式导致材料发生微生物影响的腐蚀（MIC）。为了研究这一方面，从冷却塔水中分离出细菌，并用于镀锌钢的腐蚀试验。通过对经变性梯度凝胶电泳（DGGE）分离的PCR扩增16S rDNA基因片段进行比较序列分析，确定分离菌株的身份。该分析表明，尽管经过了分离过程，但菌落并不纯净，而是由与梅氏脱硫孢菌和梭状芽孢杆菌属相关的细菌混合物组成。为了评估腐蚀效果，将镀锌钢试片与混合培养物一起孵育4、8、24、72、96、168、360和744小时，同时设置仅在无菌培养基中的对照组。通过失重法测定腐蚀速率，并通过扫描电子显微镜（SEM）观察生物膜形成和腐蚀表面。尽管产硫化物的细菌聚生体导致镀锌钢试片的腐蚀略有增加，但与先前的研究相比，可以说梭状芽孢杆菌属能够降低脱硫孢菌属菌株的腐蚀作用。
