Toxicity of Autoclaved Cystine for Lactobacillus bifidus.

Abstract
Autoclaved cystine is toxic to L. bifidus. Autoclaving in the presence of reducing sugar prevents development of the toxic product. The toxicity may be counteracted by addition, after autoclaving, of cysteine, thioglycollic or thiomalic acids, reductone, or cystine itself with ascorbic acid, but not by addition of ascorbic acid alone.