[Effect of some cations on activity of macrotetralide synthase during development of Streptomyces chrysomallus subsp. Macrotetalidi].

The activity of a specific enzymatic complex, macrotetralide synthase, is observed at all stages of Streptomyces chrysomallus subsp. macrotetralidi development. Both synthase (esterase) and hydrolase activities of the enzyme may be realized in cell-free homogenate in cultures of different age under different conditions of culturing. Hydrolase activity is observed during Streptomyces growth in synthetic and natural media with high Ca levels starting from the moment of inoculation up to the end of the third hour, when the mycelium contains the maximal level of sodium. Esterase activity is realized in cultures aged 6 hours no matter what the culturing conditions are, with the maximum of this activity observed in 12-hour mycelium in the presence of the highest level of potassium. The presence of calcium in culture medium caused the appearance of hydrolase activity of macrotetralide synthase. The possibility of enzymatic and nonenzymatic hydrolysis of antibiotics in macrotetralide producer cells has been demonstrated.