EFFECT OF CULTIVATION CONDITIONS ON THE GROWTH, POLYAMINE CONTENT, AND ULTRASTRUCTURE OF ECTOTHIORHODOSPIRA-HALOPHILA

It was found that the optimum temperature of Ectothiorhodospira haloph ila growth depends on the concentration of sodium chloride in the grow th medium and is about 37 and 32 degrees C for 20% and 10% NaCl, respe ctively. A decrease in the NaCl concentration from 20 to 10% (growth t emperature of 37 degrees C) or an increase in the growth temperature f rom 37 to 48 degrees C (NaCl concentration of 20%) decelerates growth and modifies the morphology and ultrastructure of E. halophila cells: instead of spirilla with distinct nucleoids, more or less swollen sphe roidal cells with no visible nucleoids appear. These changes are accom panied by an increase in the cellular content of the polyamines putres cine, cadaverine, spermidine, and spermine. Their physiological role i s discussed.