Some properties of the Clostridium butyricum group beta-lactamase.

Clostridium strain CB269, belonging to the butyricum group, produces a beta-lactamase. The substrate profile of this enzyme, as characterized by the microiodometric method, was that of a penicillinase: activity was slightly higher on ampicillin than on benzylpenicillin, while carbenicillin and methicillin were hydrolysed at lower rates. There was poor activity with cephalosporins. The enzyme was excreted during growth, and was inducible to a limited extent by cloxacillin or cefoxitin. The isoelectric point of the enzyme was approximately 4.1.