ACTIVITY OF THE AIB FACTOR OBSERVED IN PROKARYOTIC AND EUKARYOTIC MICROORGANISMS

Streptomyces cinnamonensis produces a new substance named AIB (for ant i-isobutyrate) factor which, on a solid medium, efficiently counteract s toxic concentrations not only of isobutyrate but also of other salts of short-chain monocarboxylic acids. In the present study we demonstr ate that the AIB factor activity is widely spread because this effect was positively detected in 25 of 31 randomly chosen microorganisms (st reptomycetes, ascomycetes, zygomycetes and basidiomycetes). The AIB fa ctor produced by the tested microorganisms on an agar media allows for germination, growth, and sporulation of the testing Streptomtyces coe licolor on an agar medium containing 20 mmol/L acetate, propionate, bu tyrate, isobutyrate, valerate, isovalerate, and 2-methylbutyrate. The activity of the AIB factor from different sources towards these substa nces differs.