The effect of mitomycin C and UV on spores before germination and two hours after it was investigated with Streptomyces narbonensis 2a producing beta-1,3/1,4-glucanglucan hydrolase (beta-glucanase). The lethal effect of mitomycin C on the germinating spores was considerably greater than that on the spores. The mutagenic activity of mitomycin C was closely related to the process of spore germination. The frequency of mutations was higher when mitomycin C acted on germinated spores. UV caused a lesser frequency of morphological mutations than mitomycin C did. The action of UV produced mutants which synthesized beta-glucanase of the exotype in the course of fermentation in a medium without an inductor.
Download full-text PDF |
Source |
---|
Nat Biotechnol
July 2002
Biochemistry Department, University of Leicester, Leicester LE1 7RH, UK.
The antibacterial properties of macrolide antibiotics (such as erythromycin, tylosin, and narbomycin) depend ultimately on the glycosylation of otherwise inactive polyketide lactones. Among the sugars commonly found in such macrolides are various 6-deoxyhexoses including the 3-dimethylamino sugars mycaminose and desosamine (4-deoxymycaminose). Some macrolides (such as tylosin) possess multiple sugar moieties, whereas others (such as narbomycin) have only single sugar substituents.
View Article and Find Full Text PDFBackground: The polyketide lactone, tylactone, is produced in Streptomyces fradiae by the TylG complex of five multifunctional proteins. As with other type I polyketide synthases, the enzyme catalysing the final elongation step (TylGV) possesses an integral thioesterase domain that is believed to be responsible for chain termination and ring closure to form tylactone, which is then glycosylated to yield tylosin. In common with other macrolide producers, S.
View Article and Find Full Text PDFDtsch Tierarztl Wochenschr
March 1992
Department of Pharmacology, Faculty of Vet. Med. Zagazig Univ., Egypt.
Josamycin is a macrolide antibiotic which is produced by fermentation of cultures of Streptomyces narbonensis. It was once administrated (18 mg/kg b. wt.
View Article and Find Full Text PDFJ Antibiot (Tokyo)
October 1984
From auxotrophic and idiotrophic mutants of Streptomyces fradiae (tylosin producer) and Streptomyces sp. AM 4900 (pikromycin producer) or Streptomyces narbonensis (narbomycin producer), prototrophic fusants were obtained at a low frequency by the protoplast fusion technique. In the cross of S.
View Article and Find Full Text PDFThe effect of mitomycin C and UV on spores before germination and two hours after it was investigated with Streptomyces narbonensis 2a producing beta-1,3/1,4-glucanglucan hydrolase (beta-glucanase). The lethal effect of mitomycin C on the germinating spores was considerably greater than that on the spores. The mutagenic activity of mitomycin C was closely related to the process of spore germination.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!