Carbon steel was exposed for long time to an inoculation continuous culturing medium of sulfate-reducing bacteria (SRB). The feed rate of medium was 10 cm3 hr-1, and the concentaration of Fe2+ of medium was kept to 0.01 mol kg-1. The corrosion behavior and metabolism of sulfate-reducing bacteria (SRB) were investigated by measuring weight change of the specimens and by using a phase-difference microscope, hydrogen sulfide gas detector, and measuring the amount of ferrous sulfide in the medium.

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... he number of SRB was above 1010 cell/cm3 after the culture of 50 days. SRB evolved a significant amount of hydrogen sulfide and ferrous sulfide after the culture above 2 days. In the period of after the culture of 50 days, the medium contained 2 types of SRB with different shapes. One was rod like shape and the other was comma like shape. In this period, pH of medium was kept almost 7 without any pH ajusting. The weight of deposited film on the specimen increased linearly with culturing time, whereas the weight of the specimen substrate due to corrosion decreased linearly with culturing time. The corrosion rate in continuous culturing medium was larger by 7 times than that in batch culture.