The Production of Hydrogen Sulphide by Yeast and by Zymomonas Anaerobia

Radiochemical experiments indicated that most of the free hydrogen sulphide excreted by a brewing yeast in wort and by Zymomonas anaerobia in beer was derived from sulphate. Sulphate was also assimilated by the organisms but most of their cellular sulphur was derived from other sources. In a synthetic beer medium, excessive amounts of hydrogen sulphide were liberated by Z. anaerobia when pantothenate was deficient. Sulphate and zinc ions stimulated sulphide production by the bacterium.