The white rot basidiomycete produces fatty aldehydes that enable fungal manganese peroxidases to degrade recalcitrant lignin structures.

The ability of some white rot basidiomycetes to remove lignin selectively from wood indicates that low molecular weight oxidants have a role in ligninolysis. These oxidants are likely free radicals generated by fungal peroxidases from compounds in the biodegrading wood. Past work supports a role for manganese peroxidases (MnPs) in the production of ligninolytic oxidants from fungal membrane lipids.

A highly diastereoselective oxidant contributes to Ligninolysis by the white rot basidiomycete Ceriporiopsis subvermispora.

The white rot basidiomycete Ceriporiopsis subvermispora delignifies wood selectively and has potential biotechnological applications. Its ability to remove lignin before the substrate porosity has increased enough to admit enzymes suggests that small diffusible oxidants contribute to delignification. A key question is whether these unidentified oxidants attack lignin via single-electron transfer (SET), in which case they are expected to cleave its propyl side chains between Cα and Cβ and to oxidize the threo-diastereomer of its predominating β-O-4-linked structures more extensively than the corresponding erythro-diastereomer.

Comparative evaluation of manganese peroxidase- and Mn(III)-initiated peroxidation of C18 unsaturated fatty acids by different methods.

The peroxidation of C18 unsaturated fatty acids by fungal manganese peroxidase (MnP)/Mn(II) and by chelated Mn(III) was studied with application of three different methods: by monitoring oxygen consumption, by measuring conjugated dienes and by thiobarbituric acid-reactive substances (TBARS) formation. All tested polyunsaturated fatty acids (PUFAs) were oxidized by MnP in the presence of Mn(II) ions but the rate of their oxidation was not directly related to degree of their unsaturation. As it has been shown by monitoring oxygen consumption and conjugated dienes formation the linoleic acid was the most easily oxidizable fatty acid for MnP/Mn(II) and chelated Mn(III).

The effect of ionising radiation on testosterone binding globulin characteristics: correction of the protein' parameters by lipid polyene complexes of fungus Laetiporus sulfureus.

Purpose: The aims of this work were: (i) To compare the effects of ionising radiation (IR) on testosterone binding globulin (TeBG) characteristics (serum concentration, cooperativity of androgen binding and affinity for hormone) in divergent mammalian species; (ii) to couple radiation effects with probable TeBG-parameter changes; and (iii) to investigate the prevention of these changes by fungal preparations (in particular - by lipid polyene complexes of Laetiporus sulphureus).

Materials And Methods: Characteristics of TeBG were investigated in microaliquots of rat and human serum samples using [(3)H]-5 alpha-dihydrotestosterone ([(3)H]-DHT) radioligand assays after in vivo exposures to IR (external gamma-sources, incorporation of (131)I-, (137)Cs-radionuclides) at experimental and post-Chernobyl radioecological conditions (doses 0.25-2.

Laccase and its role in production of extracellular reactive oxygen species during wood decay by the brown rot basidiomycete Postia placenta.

Brown rot basidiomycetes initiate wood decay by producing extracellular reactive oxygen species that depolymerize the structural polysaccharides of lignocellulose. Secreted fungal hydroquinones are considered one contributor because they have been shown to reduce Fe(3+), thus generating perhydroxyl radicals and Fe(2+), which subsequently react further to produce biodegradative hydroxyl radicals. However, many brown rot fungi also secrete high levels of oxalate, which chelates Fe(3+) tightly, making it unreactive with hydroquinones.

Differential expression in Phanerochaete chrysosporium of membrane-associated proteins relevant to lignin degradation.

Fungal lignin-degrading systems likely include membrane-associated proteins that participate in diverse processes such as uptake and oxidation of lignin fragments, production of ligninolytic secondary metabolites, and defense of the mycelium against ligninolytic oxidants. Little is known about the nature or regulation of these membrane-associated components. We grew the white rot basidiomycete Phanerochaete chrysosporium on cellulose or glucose as the carbon source and monitored the mineralization of a (14)C-labeled synthetic lignin by these cultures to assess their ligninolytic competence.

Involvement of lipid peroxidation in the degradation of a non-phenolic lignin model compound by manganese peroxidase of the litter-decomposing fungus Stropharia coronilla.

Culture liquids of the litter-decomposing basidiomycete Stropharia coronilla showed pro-oxidant activity promoting the peroxidation of linoleic acid. This activity depended on the presence of manganese peroxidase (MnP) in the fungal culture. Pro-oxidant activity maxima coincided with maximum MnP activities during the separation of extracellular proteins by anion-exchange chromatography.