Vibrio parahaemolyticus and Vibrio alginolyticus: Short Generation-Time Marine Bacteria

The growth rates of 30 different strains of Vibrio parahaemolyticus and Vibrio alginolyticus at 37 degrees C was determined. Each species consists of two major groups, one having a short generation time (12-14 min) and one with a longer generation time (20-25 min). The diversity in generation times of different strains belonging to the same species is discussed. The effect of temperature, salt, and nutrient concentrations on the growth rate of one V. alginolyticus strain (NCMB 1803) was studied. The most striking is the effect of the temperature; at 39 degrees C the generation time is 10-11 rain, while at 21 degrees C it is 60 rain. The heat of activation for growth calculating from such data is 22,580 kcal/mole/hr(-1). The ecological significance of these results is discussed.