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Evidence for repair of ultraviolet‐induced damage in Cystobacter species ( Myxobacterales )
Author(s) -
Grimm K.
Publication year - 1978
Publication title -
zeitschrift für allgemeine mikrobiologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0044-2208
DOI - 10.1002/jobm.19780180603
Subject(s) - acriflavine , caffeine , chemistry , irradiation , strain (injury) , mutant , ultraviolet , biochemistry , biology , anatomy , materials science , physics , gene , nuclear physics , endocrinology , optoelectronics
Cystobacter species strain CK 1 does not grow with more than 0.2 μg/ml acriflavine. Spontaneous two‐step mutants growing with 2 μg acriflavine per ml have been selected. One mutant (strain CK 3) was used to investigate the effect of repair inhibitors. Both strains exhibit pronounced shoulders in their UV dose curves of inactivation. Acriflavine (AF), coumarin (CU), and caffeine (CA) when incorporated in the post‐irradiation plating medium decreased survival of irradiated cells. Post‐treatment with 2 μg acriflavine/ml abolished the shoulder of the curve. Caffeine (1600 μg/ml) and coumarin (350 μg/ml) reduced it only to about 40%. It is concluded that probably two repair mechanisms are present. Pre‐treatment of the cells with 2 μg acriflavine/ml for two hours before UV‐irradiation resulted in a constant dose enhancement factor of 1.9. The protective effect is increased with the time of treatment with acriflavine. This may indicate that pyrimidine dimers are responsible for UV‐inactivation.