[Resting state in Pseudomonas fluorescens induced by a prolonged water deficit]

Various strains of Pseudomonas fluorescens showed different resistance to water deficiency in soils with a low water content (alpha w = 0.75). Humidification of dry soil reactivated the cultures. The period of reactivation took from several hours to three days and depended on the nature of inoculated strains. The growth of various strains of Pseudomonas fluorescens was studied in the conditions of a low water content in soil; the cells were investigated by electron microscopy before and after soil humidification. The results suggest that this organism can be in a certain "resting state" which is characterized by changes in the cell structure and by the time it takes the cells to reactivate after humidification of a dry soil sample.