What is the source of collagenase used for cell isolation?

Nearly all collagenases used for cell isolation are derived from culture supernatants recovered after anaerobic culture of Clostridium histolyticum. A rich broth containing digested animal meat is frequently used to ensure growth of C. histolyticum. C. histolyticum is a saprophyte that survives by secreting a diverse number of enzymes that breaks down decaying organic matter. These enzyme activities include proteases, glycosidases, lipases, and nucleases.