Isolation of sulphate transport defective mutants of Candida utilis: further evidence for a common transport system for sulphate, sulphite and thiosulphate.

Selenate-resistant mutants of Candida utilis were isolated. They did not take up sulphate while incorporation of an organic sulphur source, such as L-methionine, was similar to the wild-type strain. They grew poorly on sulphate, sulphite and thiosulphate and, as expected, grew well on methionine. Sulphite reductase activities of the mutants were similar to the wild type strain. The properties of these mutants support the view of a common transport system for sulphate, sulphite and thiosulphate.