Abstract
Thiaminase I, obtained from different sources, was treated with H_2S, and under conditions where no decomposition of thiaminase was recongnizable, their base exchange reactions were observed. On the basis of stability, thiaminases were classified into the stable and unstable ones. The latter was again divided into two groups, those unstable both in aniline and pyridine base exchange reaction, and those unstable only in aniline exchange reaction, but stable in pyridine exchange reaction, or vice versa. A method for purifying thiaminase of Bacillus tkiaminolyticus with acetone in combination with H_2S was described.
