Soil fitness and thermal sensitivity of pseudomonas corrugata strains

Soil fitness and thermal sensitivity of the bacterium Pseudomonas corrugata, was investigated in order to define possible disease management methods. Thirty minutes heat treatments at different temperatures had diverse effects on the density of bacterial populations of ten rifampicin resistant strains inoculated in soil samples. No viable cells were recovered after treatment at 60°C. Decimal reduction time at sub lethal temperatures assessed on two strains showed that the latter presented a significantly different response to heating at 40, 45 and 50°C. The behaviour of these two strains was similar at 37°C. P. corrugata strains were able to survive on uncultivated soil in pots, but the population density declined depending on the inoculated strain and on the soil texture. Higher concentration of the bacterium was observed when tomato plants were present. P. corrugata strains inoculated in the soil were able to colonise internal root tissues of tomato plants