[Biological abilities and identification of the polyene antifungal antibiotic, perspective for protection from fungi biodeterioration].

The producer of the antifungal polyene antibiotic, aimed to protect against fungial biodeterioration, has been isolated from the soil due to a target search. Based on the morphological, cultural, and biochemical abilities, the producer is related to the Streptomyces genus. It has been shown by chromatographic, spectral, physical, and chemical methods that the antibiotic synthesized by the isolated culture consists of two main components--the polyene hexaene antibiotic with a high antifungal activity and a non-polyene antibiotic with antibacterial activity.

[Effect of aeration and redox potential on the biosynthesis of the antibiotic imbricin].

The relationship between imbricin biosynthesis by Streptomyces imbricatus and the medium aeration and redox potential (Eh) was studied. The influence of the oxygen dissolution velocity within the ranges of 2.9 to 0.

[Effect of kerogen oxidation products on the biosynthesis of beta-lactamases by Escherichia coli].

Shale acid concentrate (SAC) and ozonid, the products of water-alkaline oxidation of kerogen stimulated production of beta-lactamases by E. coli. The effect was most pronounced when the SAC was added to the fermentation nutrient medium.

[Nature of the stimulating substances found in the vital activity products of yeastlike fungi].

The cultural broth of Candida tropicalis was shown to contain an active compound which stimulated the synthesis of levorin, a polyene antibiotic Succinic acid was found to stimulate the antibiotic synthesis. The stimulating effect of the active compound increased in proportion to the content of succinic acid in it and became maximal at the same concentration of succinic acid as in a pure preparation. However, succinic acid was not an only compound responsible for the elevated synthesis of the antibiotic since the biostimulating effect was higher than that of pure succinic acid.

[Acitivity of the oxidoreductases of Actinomyces levoris strain No. 28 cultured on a medium with varying redox potential values].

When the levorin-producing organism Actinomyces levoris, strain 28 was cultivated on fermentation media under conditions of decreased oxidative-reduction values, a significant decrease in the processes of the culture multiplication and antibiotic production was observed. It was shown that the marked decrease in the catalase activity accompanied by a simultaneous increase in the dehydrogenase activity was one of the causes of the decrease in the processes of the culture multiplication and levorin synthesis. Addition of potassium chloride (0.