Recently, deteriorated tubing materials buried in the soil are problematic issues. They are thoughtto be caused not only by physicochemical factors but also by biological factors such as microbesin the surrounding soil. Therefore, it is necessary to clarify the relationship between the metalcorrosion and microbial consortia in the soil.In this study, carbon steel coupons (25x10x0.5 mm) were buried in the soil taken from a forest. Allof them were conducted by using the 90 mm petri dishes. The water contents were adjusted at 0,50, 75, 100%, respectively. These samples were incubated aerobically or anaerobically for severalmonths. During the incubation, from the corroded products attached to the coupons and adjacentsoil, bacterial genome was extracted and purified by the beads-beating method and phenolchloroformmethod. 16S rRNA genes of purified genome were amplified to analyze the microbialconsortia. Statistical analysis was done by QIIME software. The corrosion rate and the corrodedsurface were also measured by weight loss and laser displacement meter, respectively.The average corrosion rate under aerobic condition was much higher than that under anaerobiccondition except for 0% water content. Under 0% water content condition, there was no significantdifference between aerobic and anaerobic conditions. Especially, when the water content was 50%and/or 75% under aerobic condition, the high corrosion rates were observed. Moreover, severepitting corrosion occurred. On the other hand, under anaerobic conditions, the water content didnot strongly affect the corrosion rate and the pitting corrosion was not observed. Concerning themicrobial consortia in the corrosion product and soil, there were big differences between aerobiccondition and anaerobic condition. However, the specific species such as sulfate-reducingbacteria that might contribute the microbiologically influence carrion has not been identified. In thefurther study, more detail statistical analysis of microbial consortia is needed.
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