Organic sulphur sources for the growth of the dermatophyte Microsporum gypseum.

The suitability of 30 organic compounds (of them 19 sulphur-containing amino acids) at a concentration of 1 mM as sulphur sources for the growth of the dermatophyte Microsporum gypseum was investigated. The dry mass of the mycelium after an 11-d growth served as a measure of utilizability. Of sulphur amino acid cystine, cysteine, reduced and oxidized glutathione, cysteic and cysteinesulphinic acids, S-sulphocysteine, lanthionine, taurine and serine sulphate were the best sources. Methionine and methionine-sulphone were utilized slightly less effectively. Other compounds were medium to poor sources and only S-carboxymethylcysteine was not utilized at all. All organic compounds that are not of amino acid type were poor sulphate sources or were utilized at all. Sodium dodecyl sulphate inhibited germination and growth completely.