The optimum parameters of cultivation of "Pseudomonas batumici"--a producer of antistaphylococcal antibiotic batumin has been established. The periodical process of culture development and antibiotic synthesis has been studied. Conditions of batumin biosynthesis are the temperature 23-25 degrees C, aeration 0.55-0.65 g O2/l.h and neutral pH of the medium. Probably batumin is not the secondary metabolite, because its synthesis begins in the culture exponential growth phase and continues in parallel with it.