A BENZENE-TOLERANT BACTERIUM UTILIZING SULFUR-COMPOUNDS ISOLATED FROM DEEP-SEA

A benzene-tolerant bacterium was isolated from a depth of 1,168 m in Sagami Bay, Japan. From its morphological and physiological properties, characteristics of halophilic growth, sulfur-compound utilization and organic solvent (OS)-tolerance, the isolate, designated as strain DS-994, seemed to be a variant strain of the genus Bacillus. DS-994 produced sulfuric acid from sodium thiosulfate in growth medium supplemented with kerosene and one of either benzene, toluene or p-xylene. When the exogenous water-insoluble organic sulfur compounds dibenzothiophene, thiophene and ethylmethylsulfide were added at 0.2% of total sulfur to diesel oil containing 5% OS, the bacterium utilized 12.5%, 10% and 15%, respectively. These values were higher than those obtained from culture in which each organic sulfur compound was suspended in the medium without diesel oil and OS.