[Level of sodium and potassium in Streptomyces chrysomallus subsp. macrotetrolidi cells--producers of macrotetralide antibiotics].

The ionophoretic macrotetrolide antibiotics selective to monovalent cations K+ and mainly to NH4+ were determined during the lag period of culture growth. At this stage the cells contain the maximal amounts of Na+ and K+. Macrotetrolides, whose selectivity to Na+ and K+ varies, can regulate the intracellular content of these cations by participating in the cation transport. The authors propose that the cells possess furosemide sensitivity and K+/Na+ ATPase transport systems.