
Full text loading...
SUMMARY: Desulphovibrio desulphuricans, strain ‘Hildenborough’, was able to use sulphite, thiosulphate, tetrathionate, metabisulphite or dithionite in place of sulphate for growth. Resting cell suspensions reduced these ions using the theoretical amounts of hydrogen and forming the theoretical amount of sulphide, except in the case of dithionite, which probably decomposed spontaneously to sulphate and sulphur before being reduced.
The organism was unable to grow with or to reduce dithionate, perdisulphate, ‘formaldehydesulphoxylate’, sulphamate, benzenesulphonate, methanesulphonate, β-hydroxyethane-sulphonate, sodium ethylsulphate, dimethylsulphone or cystine. Elementary sulphur, if purified by re-distillation, was also not attacked. Five other strains of D. desulphuricans, four of them cultivated autotrophically, were also unable to grow with pure elementary sulphur.
Colloidal sulphur permitted slow growth, or slow hydrogen absorption when a resting cell suspension was used. This effect was not due to oxide impurities in the sulphur permitting growth, as an ultra-filtrate of colloidal sulphur had considerably less activity.
A study of the rates of H2 uptake suggested that sulphur, thiosulphate and tetrathionate were not intermediates in normal sulphate reduction, but that sulphite was.