Optimizing Conditions for Vibrio Parahaemolyticus Culture and Preservation

Abstract

Vibrio parahaemolyticus is a Gram-negative bacterium of research importance nowadays due to its ability to cause diseases in both human and marine organisms. However, the bacterium expresses diminishing potential to grow under in vitro conditions particularly after conventional preservation and serial subculture. In this research, the conditions for V. parahaemolyticus culture and preservation were optimized to improve its growth and survival. In brief, V. parahaemolyticus XN9 was cultured in different conditions via varying culture medium (TSB, BHI, LB and MB), NaCl concentration (2.5, 3.0 and 3.5%), and pH (7.5, 8.0 and 8.5). The optimal culture condition was then used for optimizing preservation condition with different added glycerol concentrations (20, 30, and 40%). Survival rate was measured after 1, 2 and 3 months using plate counting method. Results showed that, the optimal culture condition for V. parahaemolyticus is 2.5% NaCl and pH 8.5 for TSB and BHI medium; 3.0% NaCl and pH 8.0 for LB; 2.5% NaCl and pH 8.0 for MB. For preservation, TSB with 20% glycerol, 2.5% NaCl and pH 8.0 provided best result. In conclusion, media such as TSB, BHI and MB can be applied to culture and preserve V. parahaemolyticus. However, to obtain optimal bacterial growth and survival, pH and salt concentration should be of concern for each one.