CHARACTERIZATION AND IDENTIFICATION OF BACTERIAL STRAINS ISOLATED FROM CORRODED CONCRETE IN THE ACCUMULATION STRATUM AND THEIR RESISTANCE LEVELS TO HEAVY-METALS

Twenty thiosulfate-utilizing bacteria that may participate in the corr osion of concrete fabrications, were isolated from the accumulation st ratum in the delta area of Hiroshima. Five of the isolated strains wer e selected for characterization, and four out of the five were classif ied into the genus Thiobacillus. Three of the five strains were furthe r identified as Thiobacillus intermedius. The growth of these five str ains in LB medium containing heavy metals was investigated. They showe d strong resistance to cadmium and zinc ions.