The wild strain Streptomyces coeruleorubidus JA 10092 was found to segregate into two spontaneous morphological variants (spo-1 and bld-1) with a different ability to form aerial mycelium in media with glucose as the main carbon source. Six new types of developmental mutants were obtained from the bald variant bld-1 after treatment with mutagens (UV light, gamma radiation, nitrous acid) and after natural selection. Formation of the aerial mycelium was fully suppressed in the bld-2 type growing on media both with glucose and with starch. The other types were bald only on starch media, forming the aerial mycelium on media with glucose; types spo-2, spo-3, spo-4 and spo-5 differed in size, shape and surface structure of spores, the type whi formed asporogenous aerial hyphae.

• MeSH
• Aminoglycosides biosynthesis   MeSH
• Glucose metabolism   MeSH
• Mutation * MeSH
• Selection, Genetic MeSH
• Starch metabolism   MeSH
• Spores, Bacterial growth & development   MeSH
• Streptomyces genetics   growth & development   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Aminoglycosides MeSH
• Glucose MeSH
• Starch MeSH

Mutants of Streptomyces coeruleorubidus, blocked in the biosynthesis of anthracycline antibiotics of the daunomycine complex, were isolated from the production strains after treatment with UV light, gamma-radiation, nitrous acid, and after natural selection; according to their different biosynthetic activity the mutants were divided into five phenotypic groups. Mutants of two of these groups produced compounds that had not yet been described in Streptomyces coeruleorubidus (aklavinone, 7-deoxyaklavinone, zeta-rhodomycinone and glycosides of epsilon-rhodomycinone). The mutants differed from the parent strains and also mutually in morphological characteristics but no direct correlation between these changes and the biosynthetic activity could be observed in most cases.

• MeSH
• Anthraquinones biosynthesis   MeSH
• Daunorubicin biosynthesis   MeSH
• Glycosides biosynthesis   MeSH
• Mutation MeSH
• Streptomyces cytology   genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anthraquinones MeSH
• Daunorubicin MeSH
• Glycosides MeSH

When improving Streptomyces coeruleorubidus JA 10092, a producer of antibiotics of the daunomycinone complex, the most active variants were found among isolates of morphological types bld-1 (with a suppressed production of the aerial mycelium on organic media containing glucose) and whi (with an asporogenic aerial mycelium on glucose media and with the bald phenotype on media containing starch). Submerged cultures of the whi mutants produced increased quantities of daunomycinone glycosides in the antibiotic complex, the amount of free anthracyclinones being simultaneously decreased. The whi strains differed from the wild type also in higher demands for aeration, concentration of glucose and in an increased production capacity in starch media. The overall antibiotic activity increased more than 40 times after a six-step selection (application of UV light, gamma-radiation, nitrous acid and natural spreads) combined with an altered fermentation technology.

• MeSH
• Daunorubicin biosynthesis   MeSH
• Culture Media MeSH
• Mutation MeSH
• Streptomyces cytology   genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Daunorubicin MeSH
• Culture Media MeSH

Variability in the production of nogalamycin by Streptomyces nogalater var. nogalater was followed in untreated and mutagenized populations of the standard strain NRRL 3035 and its spontaneous variant K-18 using the method of agar blocks with subsequent tests under submerged conditions. In both strains the most active variants were obtained by natural selection without mutagenic treatment; in this way productivity increased by 108% after two selection steps. Treatment with UV-radiation did not yield variants with a highly increased activity. Gamma-radiation extended the variability but, at the same, substantially increased the number of non-producing and low-producing isolates. Relatively high yields of (+)-variants were obtained after treatment with nitrous acid but their activity did not reach that observed in the most active spontaneous variants.

• MeSH
• Bacteriological Techniques MeSH
• Culture Media MeSH
• Naphthacenes biosynthesis   MeSH
• Nogalamycin biosynthesis   isolation & purification   MeSH
• Immersion MeSH
• Streptomyces metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Culture Media MeSH
• Naphthacenes MeSH
• Nogalamycin MeSH

The production of epsilon-pyrromycinone glycosides in Streptomyces galilaeus increased 12-fold, with respect to the wild strain, as a result of a sequential procedure including both natural selection and treatment with mutagens (nitrous acid, UV light and gamma-irradiation). Nitrous acid exhibited the highest mutagenic effect, both in increasing the productivity and in inducing blocked mutants. A mutant strain blocked in the biosynthesis of glycosides and accumulating free epsilon-pyrromycinone as the principal metabolite was obtained.

• MeSH
• Anthraquinones biosynthesis   MeSH
• Glycosides biosynthesis   MeSH
• Nitrous Acid pharmacology   MeSH
• Mutation drug effects   radiation effects   MeSH
• Antibiotics, Antineoplastic biosynthesis   MeSH
• Streptomyces drug effects   genetics   metabolism   radiation effects   MeSH
• Ultraviolet Rays MeSH
• Gamma Rays MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anthraquinones MeSH
• Glycosides MeSH
• Nitrous Acid MeSH
• Antibiotics, Antineoplastic MeSH