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 wi th colchicine, ethyl methanesulphonate (EMS), or ultraviolet (UV) irradiati on indicated varying levels of significant increases in their efficiency to transform alpha-pinene to verbenol. In case of Aspergillus sp, the UV-indu ced variant was the best performer with a 15-fold increase in biotransforma tion efficiency compared to the wild type. In case of colchicine and EMS-in duced variants the biotransformation increases were 2- and 8-fold, respecti vely. The UV-induced variant of Penicillium sp. was capable of eight fold i ncrease 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. (C) 1999 John Wiley & Sons, Inc.