REAPPRAISAL OF THE EFFECT OF TEMPERATURE ON THE GROWTH-KINETICS OF AEROMONAS-SALMONICIDA

The effect of temperature (1-34 degrees C) on the maximum specific gro wth rate of Aeromonas salmonicida could not be described by the classi cal growth models; for some strains, two optimal temperatures at 23 de grees C and 30 degrees C were observed, as well as an unexpected incre ase in the pseudolag time above 27 degrees C. This could be explained by the presence of two subsets, notably S-layer(+) and S-layer(-) sub- populations. The A(-) cells had higher growth parameters (T-opt and mu (opt)) than the A(+) cells and were selected by subcultures above 30 d egrees C. Yet the relative proportion of A(+) cells did not explain al l the variation of mu(max) versus temperature, and the growth kinetics of an Aer. salmonicida isolate remained unpredictable.