Combined mutagenesis by UV light and nitrosomethylurea of Streptomyces hygroscopicus spores

Autor: D. Noack, Gy. Rontó, B. Frunder
Rok vydání: 2007
Předmět:
Zdroj: Zeitschrift für allgemeine Mikrobiologie. 17:191-199
ISSN: 1521-4028
0044-2208
DOI: 10.1002/jobm.19770170304
Popis: By means of combined treatment with UV light and nitrosomethylurea (NMU) the spores of Streptomyces hygroscopicus were mutagenized. The rate of the colony-forming survivals exhibited two phases depending on the duration of NMU treatment. The slope of the first phase is interpreted as the result of alkylation of purin bases without repair functions. The slope of the second phase is discussed on the basis of a different content of plasmid DNA within the cells. Following the mutagenic treatment the growth rate of the colonies diminished. This effect is quantitatively measured by the aid of an automatic picture analyzer. The size distribution of the colony diameters showed two peaks in the control indicating that the Streptomyces spores grew up with one or two mycelium tubes resulting in two different growth rates. With increasing duration of NMU treatment the colonies with high diameters disappeared in favour of colonies with small diameters. By mathematical comparison it could be shown that a cooperative effect exists between the action of UV light and NMU on DNA. The spores containing DNA damages as a result of cooperative effects give rise to a distinct class of colony size. With the aid of an automatic picture analyzer it will be possible to select very effectively the desired mutants.
Databáze: OpenAIRE
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