Structure des parois de Bacillus megaterium KM I. Isolement de l'amidase et d'un enzyme nouveau sécrétés par Streptomyces albus G et actifs sur les parois de Bacillus megaterium KM et de Micrococcus lysodeikticus

Abstract

The Streptomyces albus G enzymic complex of the F2B preparation has been fractionated by zone electrophoresis in sucrose gradient. Five enzymes have been shown to be present and three of them have been fully separated. Three distinct enzymes make the casein no further precipitable by the trichloroacetic acid. They are likely not to have any action on Bacillus megaterium KM and on Micrococcus lysodeikticus cell walls. A fourth enzyme is the amidase previously studied which splits the muraminyl-alanine linkages present in the bacterial walls. The amidase does not clarify by itself the wall suspensions so far examined but enhances the lytic activity of a fifth enzyme also present in the F2B preparation. As lysozyme and Streptomyces N-acetylhexosaminidase, this fifth enzyme seems to act at the level of the polysaccharide residues of the walls basal mucopeptide but, contrary to those enzymes, its hydrolyzing action does not induce the liberation of free oligosaccharides from Micrococcus lysodeikticus walls. This enzyme will be referred to as Enzyme “32”.