Isolation and partial characterization of a mutant of Penicillium funiculosum for the saccharification of straw.

Clearing of agar plates containing ball-milled, delignified straw has been used for screening mutants of Penicillium funiculosum IMI 87160 iii. The effects of glycerol and a number of sugars on the clearing were investigated for selecting derepressed mutants. The beta-glucosidase synthesis by one such mutant, C22c, in shake flasks containing straw was not repressed by 5% glycerol, whereas activities on filter paper, CM-cellulose, and p-nitrophenyl-beta-xylosidase were only partially derepressed; xylanase was extensively derepressed. The evidence for separate control of the enzymes involved in the solubilization of straw is discussed.