Open AccessBreakdown of dimethyl sulphide by mixed cultures and by Thiobacillus thioparus
Author(s) -
Kanagawa Takahiro,
Kelly D.P.
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01340.x
Subject(s) - thiobacillus , sulfur , carbon fixation , autotroph , chemistry , methanol , mixotroph , nuclear chemistry , biochemistry , microbiology and biotechnology , heterotroph , biology , bacteria , organic chemistry , photosynthesis , genetics
Dimethyl sulphide (DMS) was degraded by acclimatized activated sludge and by a mixed culture of Thiobacillus thioparus TK‐1 and Pseudomonas sp. AK‐2. While both these organisms persisted in stable co‐culture on DMS, it was found that T. thioparus TK‐1 and the derived strain TK‐m grew in pure culture on DMS, and oxidized DMS with an apparent K m of 4.5 × 10 −5 M. During growth, all the DMS‐sulphur was oxidized stoichiometrically to sulphate but no methanol was detected in pure cultures of TK‐m. DMS‐carbon was probably converted to CO 2 , since the fixation of 14 CO 2 was progressively diluted during growth of a culture on 14 CO 2 and DMS. Growth yields were consistent with autotrophic growth, dependent on the oxidation of the methyl residues to CO 2 (probably with formaldehyde as a first intermediate) and the sulphide to sulphate. The organism thus appears to exhibit a mixture, from the one substrate, of chemolithotrophic and methylotrophic energy generation supporting autotrophic growth with CO 2 fixation.