SURVIVAL OF DISSOCIANTS OF A HYDROCARBON-OXIDIZING PSEUDOMONAS-AERUGINOSA STRAIN DURING STORAGE

The survival of R-, S-, and M-dissociants of the hydrocarbon-oxidizing strain Pseudomonas aeruginosa K-2 was compared after the storage of t he cultures by four simple methods for 18 months. The best method was storage on a slanted synthetic medium with hexadecane under mineral oi l; under these conditions, the amount of viable cells of all dissocian ts showed the smallest decrease, and the composition of the stored pop ulations underwent the least changes. During storage by other methods, the highest survival rate was demonstrated by R-cells, and M-cells we re the most sensitive; this difference resulted in changes in the comp osition of stored populations. In stored populations of S-cells, which are the most active hydrocarbon oxidizers, the relative content of po orly active but more stable R-cells increased, which could result in a decrease in the hydrocarbon-degrading ability of the culture.