Some properties of thiaminases associated with cerebrocortical necrosis

Abstract

SUMMARYThiaminases from different sources exhibit varied responses to change in pH and to differing activators, cosubstrates and inhibitors. These properties are used in an attempt to characterize the extracellular thiaminases of 17 strains of Bacillus spp. isolated from the rumen contents of animals affected with cerebrocortical necrosis and to compare these with the endogenous thiaminase present in the rumen content of such animals and with other known thiaminase-producing bacteria. Statistical analysis of the results obtained using different activators classified the isolates into two main groups corresponding to the presence of thiaminase I or thiaminase II. The pH characteristics of the rumen content enzyme differed significantly from any of the bacterial isolates examined.