Selected bacteroides species secreted various amounts of protease and glycosidase into their growth medium. Bacteroides vulgatus, distasonis, and ovatus secreted the most (31-60% of total). The secreted protease was similar in action to the protease within the organism, in that it had a broad pH optimum of 6-9, a Km app. for casein of 0.1 μM, and was inhibited by benzamidine, phenylmethylsulfonyl fluoride, diisopropylfluorophosphate (DIFP), and by an elastase inhibitor, Ac(Ala)3AlaCH2Cl.
Stan P. Riepe, Jeffrey Goldstein, David H. Alpers