Produção de cogumelos comestíveis e fenol-oxidases de Pleurotus sajor-caju e Lentinula edodes em resíduos lignocelulósicos

Abstract

Edible mushrooms Pleurotus sajor-caju PS-2001 and Lentinula edodes LE-01 were cultivated on substrates constituted of sawdust of Pinus sp. (for P. sajor-caju) or Eucalyptus sp. ( for L. edodes) added of Vitis labrusca and Malus domestica bagasse residues. The production parameters evaluated were: productivity (P), biological efficiency (BE) and yield (Y)), activities of enzymes (laccases, VAO, MnP and LiP), total soluble proteins and the N-acetyl glucosamine liberated from mycelia as a indirect estimative of biomass growth. There were three combinations of substrates (S) and a control, S1: only bagasse residues, S2: 75% bagasse residues and 25% sawdust (3:1), S3: 50% bagasse residues and 50% sawdust (1 : 1), S4: 25% bagasse residues and 75% sawdust (1:3) and S5: sawdust only (control). The results showed that bagasse residues of V. labrusca and M. domestica and sawdust of Pinus sp. were suitable for mushroom production of P. sajor-caju when used alone or in combinations, especially S4 with V. labrusca, which obtained the best results in productivity (P), biological efficiency (BE) and yield (Y) of 0.59 g day-1, 33% and 11% respectively. The substrate which showed the highest laccase activity (Lac) was S1 with M. domestica (81,995 U g-1) and the highest activity of lignin peroxidase (LiP - 26 U g-1) and also veratryl alcohol oxidase (VAO - 20.9 U g-1). The highest concentration of total protein (TP - 2803 mg g-1 of dry matter) was obtained in S4 with V. labrusca. In S3, with bagasse residues of M. domestica, P. sajor-caju showed higher activity of manganese peroxidase (MnP - 636.4 U g-1). The highest biomass was obtained in S3 with V. labrusca (8.47 mg N-acetyl glucosamine/g substrate on the 24 th day). To L. edodes, only V. labrusca ( S4) showed mushrooms production with a R of 12.8%, EB of 38.5% and Y of 0.25 g day-1. Only the bagasse M. domestica enabled the production of mushrooms in S3, S4 and S5. S4 with V. labrusca also showed the highest activity of Lac (2932 U g-1 on day 4 of culture) and the highest activity of LiP (2.73 U g-1). As the highest biomass was obtained in S1 with V. labrusca on the 16th day (17.42 mg N-acetyl glucosamine / g substrate) and S4 showed highest laccases secretion, this can show that fungal growth is not associated with increased production of Lac. S1 with V. labrusca also showed higher levels of VAO (25.94 U g-1). Higher concentration of TP (6858 mg g-1) was obtained from S1 with M. domestica. MnP and total peroxidases of L. edodes were not detected in V. labrusca or M. domestica. V. labrusca was more appropriate for laccase activity of L. edodes than M. domestica.