[Antibiotic and electrochemical properties of some natural ionophoric compounds from streptomycetes].

The systematic position of 8 Streptomyces strains isolated from nature was determined as a result of purposeful search for producers of ionophore compounds; 7 of them belong to different species. Study of the antibiotic activity of these strains and of antibiotics isolated from them as crystals permit us to hypothesize that Streptomyces may be the test organisms most fit for production of hydrophobic ionophores from streptomycetes. Alteration of the ranges of cationic and anionic selectivity by using different electrolytes indicates a high lability of the natural ionophore compounds, which may be due to their physiological function: to take an active part in the exchange processes of all inorganic ions between the cell and environment. This very property may seriously impede the use of ionophores for some practical purposes, e.g., making ion-selective electrodes.