Bacterial digestion of collagen.

That some species of Clostridia elaborate proteolytic enzymes has been known since the earliest days of bacteriology (1-3). Indeed, it was soon realized that such organisms were unusually active in this respect and played a major part in the natural processes of putrefaction (4-8). Yet neither these studies nor the much more detailed chemical investigations undertaken during and shortly after World War I (9-13) revealed the occurrence of any specific collagenolytic activity. It is true that Henry (14) reported that culture filtrates from Cl. perfringens had the property of disintegrating fresh muscle-tissue, but he does not seem to have appreciated the nature of this reaction which we now know to be due to the presence of a collagenase (15). Subsequently, however, in 1931 and 1932 Weinberg and Randin (16, 17) announced that filtrates from cultures of the anaerobe Cl. histolyticum and the aerobe B. anthracoides would slowly digest small pieces of fresh Tendo Achillis. But these important observations were ignored or forgotten until interest was once more aroused by the work of Maschmann on the protein metabolism of certain anaerobic organisms. In 1937. this worker (18, 19) isolated an enzyme from Cl. perfringens that would digest gelatin but had no effect on several other protein substrates with the solitary exception of collagen. He suggested the name "collagenase" for this agent but subsequently (20), for some undisclosed reason, withdrew the term. Several years later, MacFarlane and MacLennan (15) reported that in filtrates of Cl. perfringens Type A cultures, a substance was present which would dissolve pieces of fresh Tendo Achillis and destroy the collagen framework of muscle-tissue. They produced evidence that this activity was not due to any of the known enzymes elaborated by