Radiation for Certain Anaerobic Bacterial Spores

and only three incorporated inorganic sulfate into their microbial proteins when cysteine was present in the medium. One of these cultures, Lachnospira mvltiparus, incorporated about equal amounts of inorganic sulfate into glutathione and microbial protein when cysteine was present in the medium; but failed to form radioactive glutathione when S35 labeled inorganic sulfate was the only source of sulfur. L. multiparus utilized less than 0.2 per cent of the inorganic sulfate when cysteine was present as an alternate sulfur source as compared to 22 per cent when inorganic sulfur was the only sulfur source. This occurred even though much more growth took place in the presence of cysteine.