Factors affecting production of haemolysin by strains of Vibrio fluvialis.

The in vitro production of haemolysin by Vibrio fluvialis was studied using sheep erythrocyte. The effect of the composition of various media and different concentrations of sodium chloride on the production of haemolysin and heat-stability was investigated. Comparatively higher titre of haemolysin production was noted in brain heart infusion (BHI) broth. Adding 0.5% NaCl to BHI broth reduced the production of haemolysin; adding 5.0% NaCl to the medium totally inhibited it. The highest titre of haemolysin was produced at 30 degrees C and 37 degrees C, whereas no haemolysin was produced at 50 degrees C. Haemolytic activity was totally destroyed when heated at 56 degrees C for 30 minutes. Haemolysin could be assayed easily following this method.