Physiology and taxonomy of Thiobacillus strain TJ330, which oxidizes carbon disulphide (CS2)

A bacterium (strain TJ330) capable of using carbon disulphide (CS2) as its sole energy source in an acidic environment was isolated from a peat biofil ter used in experiments to remove CS2 and hydrogen sulphide (H2S) from air. Its physiology and taxonomy are described here. The strain oxidized CS2, H 2S and elemental sulphur to sulphate chemolithotrophically. The rate of sul phate production was highest at pH 2. The maximum growth rate constant (mu (max)) using CS2 as a substrate was 3.9 x 10(-2) h(-1) (generation time 18 h) and the Monod constant (K-s) was 0.97-2.6 mu mol l(-1) CS2 (74-198 mug l (-1)), corresponding to an equilibrium with 15-40 ppm CS2 in the headspace. The optimum growth temperature using elemental sulphur as a substrate was 28 degreesC. The strain bears morphological and physiological similarities to Thiobacillus thiooxidans, but the latter is incapable of oxidizing CS2. The strain TJ330 (DSM 8985) showed only 44.2 + 11.8% DNA homology with the type strain T. thiooxidans ATCC 19377, while its homology with T. ferrooxid ans ATCC 23270 was 17.1 + 3.4%. The strain TJ 330 represents a high-affinit y bacterium which can effectively remove low CS2 concentrations in an acid environment. These properties can be utilized in biotechnological purificat ion applications.