Davis Joshua A, Chinthala Sai Prasanna, Monty-Bromer Chelsea N, Senko John M
Department of Biology, The University of Akron, Akron, Ohio, USA.
Integrated Biosciences, The University of Akron, Akron, Ohio, USA.
Environ Microbiol Rep. 2024 Dec;16(6):e70058. doi: 10.1111/1758-2229.70058.
The metabolic potential and corrosive activities of a fermentative bacterial enrichment culture from a natural gas transmission line were characterised. Three metagenome-assembled genomes (MAGs) attributable to Cytobacillus, Lacrimispora and Staphylococcus spp. were obtained. These MAGs hosted genes involved in the fermentation of carbohydrates to organic acids, which was reflected in the acidification of the growth medium by the culture. To evaluate the corrosive activities of the culture, it was incubated in a split chamber-zero resistance ammetry (SC-ZRA) format. This involved deploying carbon steel coupons immersed in liquid medium in opposing chambers of an electrochemical cell. Measurement of current between the coupons indicated the extent and mechanism of corrosion. When the enrichment culture was added to one side of an SC-ZRA incubation with bicarbonate-buffered medium, pH change and corrosion were minimal. In bicarbonate-free medium, the culture acidified the medium, induced electron transfer from the uninoculated chamber to the inoculated chamber, and caused mass loss. These results indicate that fermenter-induced microbially influenced corrosion (MIC) is due to localised fluid acidification, inducing anodic reactions on the metal surface exposed to the microorganisms and mass loss of the non-exposed metal.
对一条天然气输送管道中发酵细菌富集培养物的代谢潜力和腐蚀活性进行了表征。获得了三个分别属于芽孢杆菌属、泪孢菌属和葡萄球菌属的宏基因组组装基因组（MAG）。这些MAG含有参与碳水化合物发酵为有机酸的基因，这在培养物对生长培养基的酸化中得到了体现。为了评估该培养物的腐蚀活性，将其以分室零电阻电流法（SC-ZRA）的形式进行培养。这包括将碳钢试片浸入电化学池相对腔室的液体培养基中。试片之间电流的测量表明了腐蚀的程度和机制。当将富集培养物添加到用碳酸氢盐缓冲培养基进行SC-ZRA培养的一侧时，pH变化和腐蚀最小。在无碳酸氢盐的培养基中，培养物使培养基酸化，诱导电子从未接种腔室转移到接种腔室，并导致质量损失。这些结果表明，发酵罐诱导的微生物影响腐蚀（MIC）是由于局部流体酸化，在暴露于微生物的金属表面诱导阳极反应，并导致未暴露金属的质量损失。
