[Irumamicin Produced by Streptomyces roseoflavus INA-1278].

The strain Streptomyces roseoflavus INA-1278 is described as a new irumamicin producer. Irumamicin 1278 is different by the antifungal activity from irumamicin produced by the world-known strain Streptomyces subflavus subsp. Irumaensis subps. nov. AM-3603.

[The hypolipidemic action of antibiotic 86/88 (enniatin B) in a hepatoblastoma G2 cell culture]. / Gipolipidemicheskoe deistvie antibiotika 86/88 (énniatina B) v kul'ture kletok gepatoblastomy G2.

A cyclodepsipeptide antibiotic 86/88 (enniatin B) with strong hypolipidemic action was isolated from the culture liquid of the fungus INA F-86/88 identified as Fusarium lateritium Nees var. stilboides (Wr.) Bilai. In the Hep G2 cell culture the antibiotic suppressed 14C-acetate incorporation into cholesterol (IC50 1.75 microM), cholesterol ethers (IC50 1 microM), triglycerides (IC50 1.3 microM) and free fatty acids (IC50 2.2 microM). The most pronounced effect of the drugs, i.e. the suppression of the cholesterol ethers synthesis is likely due not only to the ACAT inhibition but also to the inhibition of the triglyceride synthesis and the diminishing of the free fatty acids pool in the cells.

[Effect of the seeding culture media on the biosynthesis of eremomycin]. / Vliianie posevnogo materiala na biosintez éremomitsina.

Relationship of eremomycin biosynthesis to the quantity and quality of the inoculate (age, aeration rate, number of subcultures) was studied. The seed medium composition for cultivating the inoculate was defined. A procedure for cultivation of the seed material for biosynthesis of eremomycin providing an increase in the antibiotic yield by 24 per cent was developed.

[Nutrient media for the biosynthesis of eremomycin]. / Pitatel'naia sreda dlia biosinteza éremomitsina.

The composition of the medium for biosynthesis of eremomycin was optimized with mathematical design of the experiment. Optimal concentrations of the medium components were determined with the method of orthogonal latin squares. The levels of eremomycin production on the medium were 60-89 per cent higher than those on the initial medium.

[Stability of the antibiotic formation trait of the tobramycin producer Streptomyces cremeus subsp. tobramycini]. / Izuchenie stabil'nosti produtsenta tobramitsina Streptomyces cremeus subsp. tobramycini po priznaku antibiotikoobrazovaniia.

The stability of the tobramycin-producing organism was studied by the property of the antibiotic production. The organism was stored under conditions of different exposures to light and subculture on slants. The culture was also subjected to long-term storage with various methods. The organism was stable in preserving its antibiotic activity for 1.5 months when stored on the Gauze organic agar No. 2. Subcultures of the organism on this medium provided preservation of the antibiotic activity throughout 4 passages. The culture storage on millet provided preservation of the antibiotic activity for 6 months.

[Effect of culture parameters on tobramycin biosynthesis]. / Vliianie nekotorykh parametrov kul'tivirovaniia na biosintez tobramitsina.

The effect of temperature, aeration and active acidity of the medium on biosynthesis of tobramycin was studied. The optimal temperature conditions (37 degrees C) were developed. It was shown that biosynthesis of tobramycin depended on the aeration conditions, especially at the beginning of the fermentation process. The initial pH 4.9-6.35 and 6.35-7.1 were found to be optimal for the growth of the tobramycin-producing organism and biosynthesis of the antibiotic, respectively.

[Effect of several components of the nutrient medium on the biosynthesis of tobramycin]. / Vliianie nekotorykh komponentov pitatel'noi sredy na biosintez tobramitsina.

The optimal concentrations of mineral phosphorus for the growth of the tobramycin-producing organism and for the production of the antibiotic by it in the synthetic medium were determined. Introduction of an additional source of mineral phosphorus into the rich soybean medium resulted in decreased levels of antibiotic production. The stimulating effect of manganese sulfate on the biosynthesis of tobramycin in the rich medium was shown. The stimulating effect of soybean, linseed and palm oils on the production of tobramycin was evident when the fermentation period was longer.

[Optimization of the nutrient medium composition for the biosynthesis of the antibiotic tobramycin using a mathematical experimental design method]. / Optimizatsiia sostava pitatel'noi sredy dlia biosinteza antibiotika tobramitsina s pomoshch'iu matematicheskogo metoda planirovaniia éksperimenta.

The mathematical design of the experiment was used for optimization of the nutrient medium for biosynthesis of tobramycin by Streptomyces cremeus var. tobramycini. The use of the orthogonal Latin rectangles provided development of the fermentation medium composition and definition of the optimal concentration of its ingredients. The level of tobramycin production on this medium was 2 times higher than that on the initial one.

[Effect of the inoculum on tobramycin biosynthesis]. / Vliianie posevnogo materiala na biosintez tobramitsina.

The effect of the quality and quantity of the inoculum on the biosynthesis of tobramycin was studied. The medium with corn steep liquor and glycerol was found to be the optimal seed medium for the tobramycin-producing organism. It is required that the fermentation medium be supplemented with 2 per cent of the vegetative inoculum at the stationary growth phase or with an increased amount of the seed material at the exponential growth phase or at the early stage of the culture dying. Subculturing of the inoculum decreases the level of tobramycin production at the fermentation stage: when the culture of the 5th--6th generation is used, the activity of the fermentation broth decreases by 30--50 per cent.

[Effect of the pH of the medium on the growth of a carminomycin producer and on the biosynthesis of the carminomycin complex]. / Vliianie pH sredy na rost produtsenta karminomitsina i biosintez karminomitsinovogo kompleksa

The effect of the nutrient medium acidity on the growth of the carminomycin-producing organism and formation of the carminomycin complex with its aid was studied. Satisfactory development of the organism was observed when pH of the nutrient medium on the culture inoculation was 4.9 to 8.5. A shift in the alkaline and acid values of pH to 6.3--6.4 was registered during the first 24 hours of the culture growth. The biosynthesis of carminomycin depended on the culture growth time and pH value of the nutrient medium and culture fluid during the fermentation process. Maximum production of the carminomycin complex and its active components was observed on the 7th--8th day of the culture growth. The medium reaction close to the neutral one was optimal for biosynthesis of the carminomycin complex and its active components. Under acid, as well as alkaline conditions the antibiotic production was markedly lower.

[Relationship between the quality of the inoculum material and carminomycin biosynthesis by a culture of Actinomadura carminata]. / Zavisimost' biosinteza karminomitsina kul'turoi Actinomadura carminata ot kachestva posevnogo materiala.

The effect of the inoculum mycelium quality on carminomycin biosynthesis by Actinomadura carminata was studied. The time of the organism growth on the culture medium containing cornsteep liquor continued for 6 hours without losing by the inoculum of its seeding qualities during that period. The mycelium growth in the inoculum was more intensive under conditions of moderate aeration, i.e. 0.98-2.64 mg O2H1-min. Anincrease in the aeration rate up to 18.56 mg O2/1-min resulted in the growth suppression up to 40 per cent. No correlation between the aeration rate during the inoculum growth and the culture capacity for carminomycin biosynthesis and of the content of the complex in active components the fermentation medium were observed, when a 5-10 per cent of inoculum was used.

[Effect of aeration conditions on the biosynthesis of carminomycin by an actinomadura carminata culture]. / Vliianie uslovii aératsii na biosintez karminomitsina kul'turoi Actinomadura carminata

The effect of the aeration rate on biosynthesis of carminomycin by Actinomadura carminata and biochemical changes in the fermentation broth on the use of 3 complex media of different composition was studied. The carminomycin-producing organism can grow and produce the antibiotic within the ranges of the aeration changes from 0.98 to 18.56 mgO2/1-min. A decrease in the maximum rate of oxygen dissolution up to 0.98 mgO2/1-min resulted in some decrease in the activity level. Intensive aeration, i.e. 18.56 mgO2/1-min induced suppression of the antibiotic production by 25 per cent.

[Optimization of the nutrient medium makeup for the biosynthesis of carminomycin using mathematical methods of experimental design]. / Optimizatsiia sostava pitatel'noi sredy dlia biosinteza karminomitsina s pomoshch'iu matematicheskikh metodov planirovaniia éksperimenta

The nutrient medium for biosynthesis of carminomycin by Actinomadura carminata, strain 4281 was optimized with the methods of mathematical planning of the experiment. The starting variant of the medium, production of carminomycin on which was assumed equal to 100 per cent was enriched during the experiments carried out according to the patterns of the orthogonal latin squares. The production levels of carminomycin on the above medium was more than 3 times higher than those on the starting medium.