The effect of incubation temperature, sodium chloride and ascorbic acid on the growth kinetics of Aeromonas hydrophila

The effects of temperature, sodium chloride and ascorbic acid on the aerobic growth kinetics of a clinical strain of Aeromonas hydrophila were evaluated. At 5°C, ascorbic acid (1 mmol l^-1) and sodium chloride (3% w/v) inhibited the growth of the organism. At 10°C, ascorbic acid depressed only the maximum population densities (A) by approximately 2 log cycles, but not maximum specific growth rate (μ_m) or the lag time (Λ). On the contrary, NaCl caused A to increase, with the effect being greatest when the NaCl content was 1.5%. Temperature increase from 10 to 15°C resulted in an approximate doubling of μ_m and unexpectedly an apparent increase in Λ However, this apparent increase resulted from the particular manner in which the lag phase was mathematically calculated.