[Effect of the growth phase and nutrient medium on the survival of lyophilized cells of Pseudomonas denitrificans].

The influence of the growth phase and cultivation condition of Pseudomonas denitrificans on the survival of the culture after lyophilization was examined. The culture removed for drying in the stationary phase showed the highest resistance to lyophilization. The cells dried at the beginning of exponential phase displayed enhanced sensitivity to lyophilization. Addition to the cultivation medium (meat-peptone broth) of Tween-80 (0.25%) caused an increase of proteins, lipids and polysaccharides in cells and an enhancement of their telerance to lyophilization.