TEMPERATURE AND PH-DEPENDENT BLEACHING ACTIVITY OF 4 MUTAGENS IN EUGLENA-GRACILIS

The effects of temperature and pH on the ability of four mutagens to i nduce hereditary bleaching in Euglena gracilis were investigated. N-Me thyl-N'-nitro-N-nitrosoguanidine (MNNG), N-methyl-N-nitrosourea (MNU) and nitrovin (NI) induced chloroplast-free mutants in E. gracilis most effectively when pH in test medium was in the acid range (4.7 to 5.6) . In contrast, acridine orange (Ao) induced chloroplast-free mutants m ost effectively at neutral or slightly alkaline pH (7.0 to 7.7). Bleac hing activity of MNNG, NI and Ao (besides MNU) were more pronounced at higher temperatures of treatment (24 h at 37 degrees C).