Production and characterization of Moraxella bovis hemolysin

Moraxella bovis hemolysin was produced in trypticase soy broth and maximum hemolytic activity of the culture was observed during the logarithmic phase of growth. The hemolysin was filterable through a 0.22-micrometer (APD) membrane filter, heat labile, and destroyed by treatment with formalin or trypsin. There was no difference in the amount of hemolysin production by rough or smooth colony types of an isolate, although differences were observed between 2 different isolates. Partial requirement of a sulfhydryl group and divalent cations were suggestive of an enzymatic nature of M bovis hemolysin.