RESUMEN
The bacteria respond to environmental changes modifying their composition. One of the most important modifications is the variation on fatty acid composition of cellular membranes to maintain the homeoviscosity. The action of temperature, hydrostatic pressure and solvents on Pseudomonas putida has been thoroughly studied. In this paper, the combined action of the temperature and salinity on fatty acid composition of cellular membranes of Pseudomonas fluorescens GNP-OHP-3, a bacterial strain isolated from a petroleum contaminated habitat, was studied. The modifications in the fatty acid composition of Pseudomonas fluorescens GNP-OHP-3 membrane were similar to those described for other members of Pseudomonas: an increase in saturated fatty acids and a decrease in unsaturated fatty acids were observed with the increase of the temperature. Variations of main fatty acids were in general erratic in the range of assayed saline concentrations. The variation of cyclopropane fatty acids could be expressed with mathematic equations that allowed to predict their percentage in relation to sodium chloride concentration.