[Biologically active substances formed by a number of strains of the actinomycin C producer--Streptomyces chrysomallus]. / Biologicheski aktivnye veshchestva, obrazuemye riadom shtammov produtsenta aktinomitsina C--Streptomyces chrysomallus.

Biologically active substances produced by some strains of S. chrysomallus and their mutants with different levels of the differentiation were studied. Along with actinomycin C the strains produced macrotetrolides, bacteriocins and A factor-like substances. It was shown that the plasmid status of the strains was different. This suggested that the plasmid presence was a characteristic of the strains and the production of the studied substances was likely typical of S. chrysomallus.

[Hybridization of A-factor deficient mutants of Streptomyces griseus by means of fusion of protoplasts]. / Gibridizatsiia A-faktornedostatochnykh mutantov Streptomyces griseus putem sliianiia protoplastov.

Characteristics of 6 A-factor deficient mutants of S. griseus are presented. The common feature of the mutants was impairment of sporulation, formation of aerial mycelium and streptomycin synthesis. Pair-by-pair hybridization of the mutants was performed with protoplast fusion followed by regeneration. 9 pair couplings of the mutants were performed. In 3 of them sporulating recombinants were detected. The antibiotic production level in 70 hybrids was different and ranged from 0 to 1700 micrograms/ml. The morphological features of the colonies and the number of the spores formed were also different. The common feature of all the 70 sporulating hybrid strains was recovery of synthesis of A-factor, an endogenic regulator of S. griseus development. Therefore, in the A-factor deficient mutants impairment of A-factor synthesis was induced not by the plasmid elimination, as was suggested, but by mutation of separate genes.

[Use of a protoplasting method for altering the qualitative and quantitative composition of the anthracycline complex in Streptomyces peucetius var. caesius]. / Ispol'zovanie metoda protoplastirovaniia dlia izmeneniia kachestvennogo i kolichestvennogo sostava antratsiklinovogo kompleksa u Streptomyces peucetius var. caesius.

Conditions for efficient regeneration in mutant strains of the doxorubicin-producing organism Str. peucetius var. caesius were developed. The effect of the protoplast regeneration on changes in the proportion of the components of the anthracycline complex produced by these strains was shown. Variants with doxorubicin productivity 2 times higher than that of the parent strain were isolated.

[Isolation and identification of an antileukemia substance from Coprinus radiatus]. / Vydelenie i identifikatsiia protivoleikoznogo veshchestva iz Coprinus radiatus.

Conditions for cultivation of basidiomycete Coprinus radiatus on agar media and its submersion fermentation were developed. An antibiotic was isolated from the fermentation broth filtrate by extraction with ethyl acetate followed by purification on a column with silica gel. The antibiotic had a pronounced in vivo effect on hemoblastosis La. Spectral analysis of the antibiotic (UV, IR, NMR and mass spectra) showed that it was identical to patulin (a toxin).

[Formation of A-factor-type regulators by representatives of the genus Micromonospora]. / Obrazovanie reguliatorov tipa A-faktora predstaviteliami roda Micromonospora.

It is known that substances similar in their chemical structure and biological action to A-factor, a regulator of Streptomyces griseus differentiation are widely observed in streptomycetes. The present paper is concerned with studies on capacity for producing A-factor-like regulators in 13 strains belonging to 11 species of genus Micromonospora. It was shown that 7 strains had an A-factor-deficient test mutant effect analogous to the effect of A-factor. Relation of A-factor-like substance production to biosynthesis of sisomicin and sporogenesis was investigated in M. fusca var. sisomicini, strain RIA 1572. A-Factor-like substances were isolated from submersion culture of strain 1572 on the 6th-8th day of the culture growth. By the time it corresponded to the highest number of the spores in the medium. The highest levels of sisomicin were detected on the 3rd day of the fermentation process. After that period its concentration markedly lowered. Exogenic addition of A-factor had no effect on sisomicin biosynthesis but resulted in increased numbers of the spores.

[Valinomycin biosynthesis and the dynamics of the content of macroergic phosphorus compounds in Streptomyces cyaneofuscatus]. / Biosintez valinomitsina i dinamika soderzhaniia makroérgicheskikh fosfornykh soedinenii u Streptomyces cyaneofuscatus.

The pattern of accumulation and consumption of macroergic phosphoric compounds such as polyphosphates, pyrophosphate and ATP in the mycelium of the valinomycin-producing organism was studied. The content of high polymeric polyphosphates in the high productive strain A of S. cyaneofuscatus was much lower than that in the isogenic low productive strain B, which was indicative of their participation in providing bioenergetics of antibiotic production. Cultivation of the low productive strain B in the presence or absence of the A-factor showed that the mutant reduced its sporulation and provided a 40-fold increase in biosynthesis of valinomycin. However, no difference in consumption of diverse polyphosphate fractions was observed.

[Regulators of differentiation in Streptomyces cyaneofuscatus]. / Reguliatory differentsiatsii Streptomyces cyaneofuscatus.

Streptomyces cyaneofuscatus PRL 1642 producing valinomycin was shown to synthesize bioregulators of differentiation similar to A factor. The regulators stimulate spore formation and streptomycin synthesis in a Streptomyces griseus 1439 mutant deficient in A factor. Some S. cyaneofuscatus mutants respond to A factor addition into the medium by an increase in valinomycin synthesis and a change in morphological properties. The regulators from S. cyaneofuscatus are more effective toward mutants of this species than toward S. griseus mutants.

[Regulation of spore-formation in Streptomyces galbus mutants]. / Reguliatsiia sporoobrazovaniia u mutantov Streptomyces galbus.

Some asporogenous strains of Streptomyces galbus recover the capacity to form aerial mycelium and spores when they are grown together with the parent sporulating strain under the conditions of superficial cultivation. The sporulating strain of Str. griseus that produces the A factor, a bioregulator, does not restore sporogenesis in asporogenous variants of Str. galbus, in contrast to Str. griseus. Therefore, Str. galbus must liberate a specific compound which controls spore formation in this species.

[Secretion of substances by different actinomycetes which induce sporulation by an asporogenic mutant of Streptomyces griseus]. / Vydelenie fazlichnymi aktinomitsetami veshchestv, vyzyvaiushchikh sporuliatsiiu u asporogennogo mutanta Streptomyces griseus.

The asporogenic mutant of Streptomyces griseus 1439 sporulates under the action of factor A, a regulator of differentiation, liberated by the parent strain. It has been found that 11 out of 30 cultures belonging to various species of actinomycetes induce formation of spores in strain 1439. The response of this strain to each of the 11 strains of actinomycetes has shown that they liberate stimulating substances in different quantities and at different periods of time.

[Interaction of streptidin-dependent Actinomyces streptomycini (Streptomyces griseus) mutants No. 170 and 145 with mutants having blocks at various stages of streptomycin biosynthesis]. / Izuchenie vzaimodeistviia streptidin-zavisimykh mutantov Actinomyces streptomycini (Streptomyces griseus) No. 170 i 145 s mutantami, imeiushchimi bloki na razlichnykh étapakh biosinteza streptomitsina.

In complementation analysis of low active streptidine dependent strains of Act. streptomycini, 170 and 145 with mutants having different blocks in biosynthesis of streptomycin it was found that these strains were the donors of some thermostable substances and could reduce the biosynthesis of streptomycin in the mutants having impairements in biosynthesis of streptidine and streptobiosamine, as well as in a number of strains with unknown blocks. It is supposed that the substances produced by mutants 170 and 145 were intermediate products in streptomycin biosynthesis.

[Slightly active Actinomyces streptomycini (Streptomyces griseus) mutants having a protein in the biosynthesis of the streptidine portion of the streptomycin molecule]. / Maloaktivnye mutanty Actinomyces streptomycini (Streptomyces griseus), imeiushchie belok v biosinteze streptidinovoi chasti molekuly streptomitsina.

Twelve mutants having a block in biosynthesis of the streptidine part of the streptomyciu molecule were selected under the effect of nitrozomethylbiuret. These 12 strains responded by an increase in the level of the antibiotic production to the addition of streptidine to the cultivation medium. The complementation analysis showed that every streptidine-dependent mutant interacted at least with 2 other mutants. On the basis of the data obtained it is possible to conclude that all 12 mutants had blocks in streptidine biosynthesis but at different stages of this complicated process.

[Actinomyces streptomycini mutants blocked in the biosynthesis of the streptobiosamine portion of the streptomycin molecule]. / Mutanty Actinomyces streptomycini, blokirovannye po biosintezu streptobiozaminovoi chasti molekuly streptomitsina.

Four low active mutants of Act. streptomycini were obtained under the effect of nitrozo-methylbiuret. The mutants increased their antibiotic production level, when streptobiosamine was present in the formentation medium. It was shown that in 3 out of the 4 mutants the highest antibiotic yield was in the medium containing streptobiosamine in an amount of 1 mg/ml and in 1 strain the highest yield was in the medium with 0.5 mg/ml of streptobiosamine. When the mutants were grown in a medium containing N-methyl-L-glucosamine no increase in streptomycin production was registered.

[Induced variability of Streptomyces galbus]. / Indutsirovannaia izmenchivost' Streptomyces galbus.

A-factor, a regulating substance is an obligatory participant of streptomycin biosynthesis by Str. griseus. Str. galbus also synthesizes streptomycin but without participation of A-factor. Mutant with various morphological properties were obtained under the effect of ethylenimine. No correlation between spore formation and streptomycin synthesis was found in the mutants of Str. galbus unlike Str. griseus. Correlation between a decrease in the capacity for production of a dark brown pigment and an increase in the level of streptomycin biosynthesis was shown: the mutants with the dark brown pigment did not synthesize streptomycin, while the mutants without the pigment synthesized streptomycin in the amounts 10-14 times higher than those in the initial strain. The same as the initial strain, the mutants of Str. galbus had no A-factor and did not respond to its addition into the medium by changing their properties and streptomycin synthesis.

[Actinomyces streptomycini mutant blocked in streptidine biosynthesis]. / Mutant Actinomyces streptomycini, blokirovannyi po biosintezu streptidina

Mutant 170 not capable of forming streptidine and streptomycin was obtained using chemical mutagenes. This mutant can produce streptomycin only with suplementation of exogenous streptidine. Experiment with labeled C14-streptidine showed its specific incorporation in streptidine moiety of streptomycin molecule.