Strain improvement of Trametes hirsuta by physical and chemical mutagenesis for better laccases production.

ABSTRACT

The Laccases production efficiency was investigated by the wild fungal strains Trametes hirsuta by treating it with physical mutagen [ultraviolet radiation (UV) and X-rays] and chemical mutagens [Ethidium bromide, Colchicine and Hydrogen peroxide]. The present work aimed to apply mutagenesis for enhancement of the enzyme production. Effective changes were observed in the efficiency of enzyme production when treated with physical and chemical mutagens. The effect of X-rays showed a decrease in production with increasing exposure in T. hirsuta (Max. at 2 sec.). UV irradiation influenced the enzyme production with higher exposure time (8 minutes) but the maximum dosage led to inhibition in fungal growth and low enzyme production. Among the three chemical mutagens used, hydrogen peroxide was found to be having lethal effects to the fungi but a minimum concentration (2 µg/mL) was positively effecting enzyme production. Colchicine showed increase in enzyme production with increasing concentrations (Max. at 9 µg) and with Ethidium bromide, maximum enzyme production was observed at concentration of 7 µg/ mL. The study on morphological differences in wild and mutant shows that there was an improvement in strains of the white rot fungi.