mutagenic effect of nitrous acid, acriflavine and diethylamine on streptomyces scabies

ABSTRACT

The mean survival percentages for the concentrations 0.02 and 0.2 M NaNO2 in liquid MM after incubation for 24 hr at 280 were found to be 4.64 and 3.57, respectively. Out of 161 colonies tested from the concentration of 0.02 M, 64 auxotrophic mutants were isolated. However, out of 150 colonies tested from the concentration of 0.2 M, a total of 74 auxotrphic mutants was isolated. All these mutants reverted to the wild type. The mean survival percentages for the concentrations 10, 20 and 30 mg AC/20 ml solid CM and incubation for 4 days at 280 were 9.33,4.00 and 1.73, respectively. The mean survival percentages for the concentrations 10,20 and 30 mg AC/100 ml liquid MM and incubation for 4 days at 28° were 9.09, 6.66 and 5.64, respectively. The mean survival perecentages for the concentrations 10, 20 and 30 mg AC + 2 mg streptopencid/20 ml solid CM and incubation for 7 days at 28° were 0.67,0.12 and Q respectively. Three biochemical mutants were obtained from a sample of 127 colonies isolated from 30 mg AC + 2 mg streptopencid/20 ml solid CM. The mutants were ad, his and met requiring mutants. The mean survival percentages for the concentrations 0.05 and 0.1 ml DEA/20 ml solid CM and incubation for 4 days at 280 were 1.83 and 0.15, respectively. Twenty biochemical mutants were obtained from conidial suspensions treated with 0.05 ml DEA which gave a survival percentage of 1.83. These mutants were;- 3 his, 4 ad, 2 arg, 2 trypt, 1 ad or lys, 1 met or trypt, 1 ad or trypt, 1 his or trypt, 1 his or arg, 1 his or met and 21eu or trypt. The possibility for obtaining such latter mutants were discussed