The invention relates to recombinant nucleic acid and polypeptides encoding collagenase I and collagenase II, methods for the preparation thereof and methods for the use thereof. The present invention also provides a method for detecting the secretion of a hemolytic toxin by a bacterial production strain, wherein the production strain produces a collagenase, prior to therapeutic administration of said collagenase to a patient and methods for detecting the presence of a hemolytic toxin in a collagenase composition.