Screening of Novel Basidiomycetes for the Production of Lig- nocellulolytic Enzymes During Fermentation of Food Wastes

Nine species of white-rot basidiomycetes isolated from the forests of Georgia have been screened for the endoglucanase, xylanase, laccase, and manganese peroxidase production in both glycerol-containing synthetic medium and mandarin peels-based medium. Irpex lacteus and Trametes ochracea expressed the highest hydrolases activity in submerged and solid-state fermentation (SSF), respectively, of ethanol production residue (EPR). Lenzites betulina appeared to be very promising producer of laccase in both synthetic (52.5 U ml -1 ) and complex (76.7 U ml -1 ) media. The tested white-rot fungi exhibited quite different responses to growth substrates used. Mandarin peelings, ethanol production residue, and wheat bran appeared to be excellent growth substrates for the production of complex preparations of hydrolases and oxidases. The same substrates as well as walnut pericarp enhanced laccase and MnP secretion. In addition, the ratio of individual enzymes in final preparations signifi cantly depended on growth substrate. Thus, the laccase/MnP ratio changed from 3 to 548 with substitution of EPR by walnut pericarp in submerged fermentation by L. betulina. Usually, the submerged fermentation of lignocellulosic materials was preferable for the target enzyme secretion. However, the SSF of wheat bran was essential for the CMCase production by I. lacteus, L. betulina, and S. hirsutum. The SSF of EPR was preferable for the laccase production by G. resinaceum, L. betulina, and T. ochracea while the SSF of wheat bran favored MnP accumulation as compared to submerged cultivation.