Characteristics of Thiobacillus thioparus and its thiocyanate assimilation

Abstract

Thiocyanate-assimilating bacterium, TK 21, was isolated from activated sludge used for the treatment of thiocyanate contained in coke-oven liquor. This organism oxidized thiosulfate and elemental sulfur, causinga decrease of pH of the medium. These facts indicated that it belongs to the genus Thiobacillus. Potassium thiocyanate (0.5 g/ℓ) was completely assimilated during 60 h. Thiosulfate inhibited the assimilation of thiocyanate but elemental sulfur did not. This bacterium did not evolve cyanide as its oxidation product after the decomposition of thiocyanate. The isolated bacterium was identified as Thiobacillus thioparus. Examination of the composition of cellular fatty acid of three strains of T. thioparus showed that they possessed 3-hydroxy fatty acids of C10 and C12; saturated straight chains of C10, C12, C15, C16, C17, and C18; mono-unsaturated straight chains of C16 and C18; and cyclopropane acid of C17.