The effect of the inoculum quality on carminomycin biosynthesis by A. carminata was studied. The growth was more intensive under conditions of moderate aeration, i.e., 0.98-0.64 mg O2/l.cntdot.min. An increase in the aeration rate up to 18.56 mg O2/l.cntdot.min resulted in the growth suppression up to 40%. No correlation between the aeration rate during the inoculum growth and the culture capacity for carminomycin biosynthesis in the fermentation medium was recorded. The highest levels of the antibiotic synthesis were observed when a 5-10% inoculum was used.