Effect of nutrient medium composition on laccase and manganese peroxidase activity in medicinal mushrooms

Twenty strains belonging to 17 species and 14 genera (Bjerkandera, Cerrena, Coriolopsis, Fomes, Ganoderma, Grifola, Inonotus, Lentinus, Phellinus, Pleurotus, Pseudotrametes, Schizophyllum, Trametes, and Trichaptum) of higher Basidiomycetes were evaluated for their ability to produce laccase and manganese peroxidase (MnP) in submerged cultivation in glycerol and wheat bran-containing media. Screening results showed that the enzyme synthesis is species- and strain-dependent. The majority of the tested fungi expressed only traces or very low laccase and MnP activities during submerged growth in synthetic medium. Only Coriolopsis gallica 1184 accumulated high levels of laccase activity (19.3 U/mL) in the absence of any specific inductor. Wheat bran significantly promoted enzyme synthesis in the white-rot fungi. C. gallica 1184 followed by Ganoderma tsugae 1032 secreted very high levels of laccase activity (67.7 and 23.1 U/mL, respectively). Trichaptum biforme 117 and Trametes ochracea 1215 appeared to be the best producers of MnP (340-350 U/L). Lignocellulosic growth substrate significantly affected enzyme synthesis. Mandarin peels and kiwi were the most appropriate growth substrates for the laccase production by Coriolopsis gallica 1184 (91.8-95.9 U/mL), wheat bran followed by mandarin peels stimulated laccase production by Ganoderma tsugae 1032 (17.1 U/mL), whereas only banana peels significantly enhanced laccase secretion by Trametes ochracea 1215 (14.3 U/mL).