Strain improvement of Aspergillus sp. and Penicillium sp. by induced mutation for biotransformation of alpha-pinene to verbenol.

Variants of Aspergillus sp. and Penicillium sp. obtained after treatment with colchicine, ethyl methanesulphonate (EMS), or ultraviolet (UV) irradiation indicated varying levels of significant increases in their efficiency to transform alpha-pinene to verbenol. In case of Aspergillus sp. the UV-induced variant was the best performer with a 15-fold increase in biotransformation efficiency compared to the wild type. In case of colchicine and EMS-induced variants the biotransformation increases were 2- and 8-fold, respectively. The UV-induced variant of Penicillium sp. was capable of eight fold increase in efficiency while the colchicine- and EMS-induced variants were 1.5- and 2-fold, respectively. The variants were characterised with respect to changes in colony morphology, spore dimension, DNA content, and products formed, viz. verbenol and verbenone.