Effect of incubation temperature on growth parameters of Pseudoalteromonas antarctica NF and its production of extracellular polymeric substancesdagger.

AIM

To evaluate the effect of temperature on growth parameters and on extracellular polymeric substance (EPS) production for Pseudoalteromonas antarctica NF(3).

METHODS AND RESULTS

For this purpose, three growth parameters, lag time (lambda), maximum growth rate (mu) and maximum population density (A), were calculated with the predictive Gompertz model. To evaluate the variations in mu with respect to temperature, the secondary Arrhenius and the square root models were used. Below the optimal growth temperature (17.5 degrees C), the growth of P. antarctica was separated into two domains at the critical temperature of 12 degrees C. Within the suboptimal domain (12-17.5 degrees C), the temperature characteristic was the lowest (5.29 kcal mol(-1)). Growth population densities were maintained over the entire physiological portion assayed (5-17.5 degrees C). Higher crude EPS production was found at temperatures included in the cold domain (5-12 degrees C).

CONCLUSIONS

All calculated parameters revealed an optimal adaptation of this strain to cold temperatures.

SIGNIFICANCE AND IMPACT OF THE STUDY

The knowledge of the influence of temperature on growth parameters of P. antarctica NF(3) and on EPS production could improve the production of this extracellular polymeric substance that is currently being used in the cosmetic and pharmaceutical industries.