Abstract
Cell free preparation obtained from M. pyogenes by shaking its aqueous suspension with glass powder under the condition of a low temperature and vacuum was able to hydrolyze thiamine to its moieties. That the factor in the preparation responsible for the thiamine decomposition is attributable to an enzyme "thiaminase II" is shown by the following facts : (a) this factor was not thermostable, had optimum pH and temperature for its action and was precipitated acetone ; (b) the action of the preparation was not accerelated by aniline or pyridine and was impeded from heavy metals. The Michaelis constant of the enzyme was calculated by the author as (2.4±0.25)×10^<-5> M/l at 30℃ and pH6.5.
