Ligno(hemi)cellulolytic Enzyme Profiles during the Developmental Cycle of the Royal Oyster Medicinal Mushroom Pleurotus eryngii (Agaricomycetes) Grown on Supplemented Agri-Wastes.

We have determined the production profiles of major ligno(hemi)cellulolytic enzymes at different stages of the mushroom development cycle during industrial scale cultivation of Pleurotus eryngii on supplemented agri-wastes. Endo-1,4-β-glucanase, cellobiohydrolase and endoxylanase levels remained relatively low during substrate colonization, increased sharply when small fruit bodies appeared, and peaked at maturation. β-Glucosidase and β-xylosidase levels decreased when substrate colonization was complete, increased with the appearance of small fruit bodies and primordia, respectively, and reached maxima at maturation.

Comparison of endoglucanase-1 (EG1) induction in the edible straw mushroom Volvariella volvacea by lactose and/or cellobiose with or without added sorbose.

We have compared the induction of an endoglucanase (EG1) by α-lactose and/or cellobiose, with or without added L-sorbose, in submerged cultures of Volvariella volvacea, to better understand the mechanism whereby cellulase formation is triggered by these soluble disaccharides. EG1 levels induced by α-lactose and cellobiose were 28.6% and 6.

Molecular cloning and transcriptional expression analysis of an intracellular beta-glucosidase, a family 3 glycosyl hydrolase, from the edible straw mushroom, Volvariella volvacea.

A beta-glucosidase, with a molecular mass of 95 kDa, was isolated from extracts of Volvariella volvacea mycelium grown on crystalline cellulose. Degenerate primers based on the N-terminal sequences of purified beta-glucosidase and two protease-generated peptides were used to generate cDNA fragments encoding a portion of the beta-glucosidase gene (bgl), and rapid amplification of cDNA ends was used to obtain full-length cDNA clones. The cDNA of bgl contained an ORF of 2586 bp coding for 862 amino acids.

Cloning of multiple cellulase cDNAs from Volvariella volvacea and their differential expression during substrate colonization and fruiting.

We used PCR-based methods to clone and sequence four previously unidentified cellulase cDNAs: cbhI-I, cbhI-II, cbhII-I and egII. CbhI-I, cbhI-II and cbhII-I consist of 1710, 1610 and 1453 bp, respectively, and encode for 512, 458 and 442 amino acids, respectively. EgII consists of 1180 bp encoding for 310 amino acids, and belongs to family 61 of the glycosyl hydrolases.

Molecular cloning of a new laccase from the edible straw mushroom Volvariella volvacea: possible involvement in fruit body development.

Cloning of a laccase-encoding cDNA from the edible straw mushroom, Volvariella volvacea, was performed using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends. The cDNA of the putative laccase gene (lac4) consisted of 1689 bp, including an open reading frame encoding a 23-amino acid signal peptide at the N-terminal end and a 540-amino acid mature protein with a predicted molecular mass of 58173 Da and a pI value of 6.1.

Biochemical and molecular characterization of a laccase from the edible straw mushroom, Volvariella volvacea.

We have isolated a laccase (lac1) from culture fluid of Volvariella volvacea, grown in a defined medium containing 150 micro m CuSO4, by ion-exchange and gel filtration chromatography. Lac1 has a molecular mass of 58 kDa as determined by SDS/PAGE and an isoelectric point of 3.7.

Induction of laccase activity in the edible straw mushroom, Volvariella volvacea.

Volvariella volvacea, strain V14, produces multiple forms of extracellular laccase when grown in submerged culture in a defined medium with glucose as sole carbon source, and on cotton waste 'compost' representative of the conditions used for industrial-scale mushroom cultivation. In liquid culture, enzyme synthesis is associated with the onset of secondary growth, and is positively regulated by copper (up to 200 microM CuSO(4)) and by various aromatic compounds. In solid-state systems, only low levels of laccase are detectable during the vegetative growth phase but enzyme activity increases sharply at the onset of fruiting and during sporophore development.

L-DOPA oxidation products prevent H2O2-induced oxidative damage to cellular DNA.

Using the single-cell gel electrophoresis ("Comet") assay, we show that tyrosinase-generated L-DOPA oxidation products prevent H2O2-induced oxidative DNA damage in cultured tissue cells. We propose that these oxidation products trigger cellular processes that up-regulate the overall antioxidant status of the cell, and could be incorporated into treatments of pathological conditions associated with elevated oxidative DNA damage and other manifestations of increased oxidative stress.

Role of tyrosinase in the genoprotective effect of the edible mushroom, Agaricus bisporus.

A heat-labile protein has been identified in fruit bodies of the edible mushroom, Agaricus bisporus, which protects Raji cells (a human lymphoma cell line) against H2O2-induced oxidative damage to cellular DNA. This protein has been purified following salt fractionation, combined with ion-exchange, hydrophobic interaction and adsorption chromatography. Based on catalytic and electrophoretic properties, and inhibition studies using tropolone, the protein was identified as tyrosinase.

Mushroom-derived preparations in the prevention of H2O2-induced oxidative damage to cellular DNA.

Aqueous extracts of the sporophores of eight mushroom species were assessed for their ability to prevent H2O2-induced oxidative damage to cellular DNA using the single-cell gel electrophoresis ("Comet") assay. The highest genoprotective effects were obtained with cold (20 degrees C) and hot (100 degrees C) water extracts of Agaricus bisporus and Ganoderma lucidum fruit bodies, respectively. No protective effects were observed with Mushroom Derived Preparations (MDPs) from Flammulina velutipes, Auricularia auricula, Hypsizygus marmoreus, Lentinula edodes, Pleurotus sajor-caju, and Volvariella volvacea.