ISOLATION AND CHARACTERIZATION OF A NEW SPORE-FORMING SULFATE-REDUCING BACTERIUM GROWING BY COMPLETE OXIDATION OF CATECHOL

A new mesophilic sulfate-reducing bacterium, strain Groll, was isolated from a benzoate enrichment culture inoculated with black mud from a freshwater ditch. The isolate was a spore-forming, rod-shaped, motile, gram-positive bacterium. This isolate was able of complete oxidation of several aromatic compounds including phenol, catechol, benzoate, p- and m-cresol, benzyl alcohol and vanillate. With hydrogen and carbon dioxide, formate or O-methylated aromatic compounds, autotrophic growth during sulfate reduction or homoacetogenesis was demonstrated. Lactate was not used as a substrate. SO42-, SO32-, and S2O32- were utilized as electron acceptors. Although strain Groll originated from a freshwater habitat, salt concentrations of up to 30 g . l-1 were tolerated. The optimum temperature for growth was 35-37-degrees-C. The G + C content of DNA was 42.1 mol%. This isolate is described as a new species of the genus Desulfotomaculum.