Aims: To isolate the protoplasts from Penicillium sp. PT95 and carry out laser mutagenesis to attain high-yield mutant strain for carotenoid production.
Methods and results: The mycelial pellets of PT95 strain were digested with the lytic enzyme for 3 h in order to attain protoplasts. The prepared protoplasts were irradiated using helium neon (He-Ne) laser. Among all regenerated colonies isolated from irradiated protoplasts, five colonies proved to be able to form sclerotia. The five colonies were named as strains L01, L02, L03, L04 and L05, respectively. Whereas, among all regenerated colonies isolated from no-irradiated protoplasts, no colonies were found to form sclerotia. Strains L01, L02, L03, L04 and L05 showed higher carotenoid yield than the original strain in Czapek's agar medium. Strain L05 gave the highest pigment yield of 381 microg per plate, which was 2.54 times higher than that of original strain.
Conclusions: These results suggest that PT95 strain may be mutagenized using laser-irradiation to obtain higher-yield mutant strains for carotenoid production.
Significance and impact of the study: These data prompted us to consider that several attempts should be made to improve carotenoid production in PT95 by strain selection using classical screening and mutagenesis techniques.