Microbiologically influenced corrosion (MIC) of copper by Desulfovibrio vulgaris, a sulfate reducing bacterium (SRB), was investigated in anaerobic vials with a fixed broth volume of 40 mL but varied headspace volumes (10 mL, 85 mL 160 mL). It was found that the headspace volume variation had a very large effect on the dissolved [H2S] in the broth and the cell counts of planktonic and sessile cells, as well as Cu corrosion severity. A 16× smaller headspace led to a 1.6-fold increase in the dissolved [H2S], a 13-fold decrease in sessile SRB cell count, a 32-fold decrease in planktonic cell count and a 3.7-fold increase of Cu weight loss. SEM images revealed that different headspace volumes caused different corrosion patterns on the immersed coupons. With a lower headspace volume, pitting corrosion was observed, while with a higher headspace volume, intergranular corrosion was seen. The results confirmed that SRB MIC of Cu belongs to metabolite-MIC (M-MIC) by H2S, unlike SRB MIC of carbon steel that belongs to extracellular electron transfer-MIC (EET-MIC) that is directly correlated with sessile cell counts rather than dissolved [H2S]. .

中文翻译：

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硫酸盐还原细菌在不同顶空体积的厌氧小瓶中对铜的腐蚀。

在固定培养液体积为40 mL但顶空体积有所变化（10 mL，85 mL和160 mL）的厌氧小瓶中，研究了硫酸盐还原细菌（SRB）脱硫弧菌（Desulfovibrio vulgaris）对铜的微生物学影响（MIC）。发现顶空体积变化对肉汤中溶解的[H2S]，浮游和无柄细胞的细胞数以及铜腐蚀的严重程度有很大的影响。顶部空间缩小16倍会导致溶解的[H2S]增长1.6倍，无柄SRB细胞数减少13倍，浮游细胞数减少32倍，Cu失重增加3.7倍。SEM图像显示，不同的顶部空间体积对浸入的试样产生不同的腐蚀方式。顶空体积较小时，观察到点蚀，而顶空体积较大时，观察到晶间腐蚀。结果证实，Cu的SRB MIC通过H2S属于代谢物MIC（M-MIC），与碳钢的SRB MIC属于细胞外电子转移MIC（EET-MIC）不同，后者直接与无数细胞计数相关，而不是溶解[H2S]。。