Nutritional regulation of synthetic lignin (DHP) degradation by the selective white-rot fungus Phlebia (Merulius) tremellosa: effects of glucose and other cosubstrates

1991 ◽  
Vol 69 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Ian D. Reid ◽  
Alain M. Deschamps
Keyword(s):  
Energy Source ◽  
Lignin Degradation ◽  
Tricarboxylic Acid Cycle ◽  
Wood Decay ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Nutritional Regulation ◽  
Carbohydrate Degradation ◽  
Lignin Metabolism

Phlebia tremellosa is a white-rot fungus which selectively degrades lignin, i.e., its ratio of lignin degradation to carbohydrate degradation during wood decay is higher than that of "simultaneous" white rots. Its need for a cosubstrate to support lignin degradation, and the effect of glucose supply on rate and extent of lignin metabolism, were examined in a synthetic, nitrogen-limited medium. Lignin metabolism by P. tremellosa, like simultaneous white rots, requires a cosubstrate. Glucose partially represses lignin degradation, but it is metabolized to extracellular intermediates, including ethanol. Subsequent utilization of ethanol as energy source supports rapid lignin degradation. Phlebia tremellosa grows well with cellulose, glucose, xylose, ethanol, or lactate as sole carbon (energy) source, and more slowly with glycerol or methanol. It appears unable to use kraft lignin, ferulate, vanillin, or acetate as sole carbon source. Cellulose, glycerol, and ethanol efficiently supported degradation of ring-labelled lignin to CO2, whereas glucose, xylose, and lactate were less efficient cosubstrates; methanol did not support lignin degradation. A relationship between tricarboxylic acid cycle operation and metabolism of lignin ring carbons to CO2, is suggested. Key words: lignin biodegradation, cosubstrate, glucose, ethanol, selectivity.

Enhancement of lignin degradation and laccase activity in Pleurotus ostreatus by cotton stalk extract

1998 ◽  
Vol 44 (7) ◽  
pp. 676-680 ◽  
Author(s):  
Orly Ardon ◽  
Zohar Kerem ◽  
Yitzhak Hadar
Keyword(s):  
Oxygen Consumption ◽  
Pleurotus Ostreatus ◽  
Lignin Degradation ◽  
Laccase Activity ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Cotton Stalk ◽  
Fermentation System ◽  
Uv Visible

The white rot fungus Pleurotus ostreatus was grown in a chemically defined solid state fermentation system amended with cotton stalk extract (CSE).Treated cultures exhibited increased laccase activity as well as enhanced lignin mineralization. Mineralization of [14C]lignin initialized 4 days earlier in CSE-supplemented cultures than in control cultures. Total mineralization in the first 16 days was 15% in the CSE-treated cultures, compared with only 7% in the controls. Cotton stalk extract also contained compounds that serve as substrates for laccase purified from P. ostreatus as shown by oxygen consumption, as well as changes in the UV–visible spectrum.Key words: cotton, Pleurotusostreatus, white rot, laccase, lignin biodegradation.

scholarly journals Transcriptomics analysis reveals the high biodegradation efficiency of white-rot fungus Phanerochaete sordida YK-624 on native lignin

2020 ◽  
Author(s):  
Jianqiao Wang ◽  
Tomohiro Suzuki ◽  
Hideo Dohra ◽  
Toshio Mori ◽  
Hirokazu Kawagishi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lignin Degradation ◽  
Ligninolytic Enzymes ◽  
Organic Matrix ◽  
Tca Cycle ◽  
Underlying Mechanism ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Phanerochaete Sordida

Abstract Background Lignocellulosic biomass is an organic matrix composed of cellulose, hemicellulose, and lignin. In nature, lignin degradation by basidiomycetes is the key step in lignocellulose decay. The white-rot fungus Phanerochaete sordida YK-624 (YK-624) has been extensively studied due to its high lignin degradation ability. In our previous study, it was demonstrated that YK-624 can secrete lignin peroxidase and manganese peroxidase for lignin degradation. However, the underlying mechanism for lignin degradation by YK-624 remains unknown.Results Here, we analyzed YK-624 gene expression following growth under ligninolytic and nonligninolytic conditions and compared the differentially expressed genes in YK-624 to those in the model white-rot fungus P. chrysosporium by next-generation sequencing. More ligninolytic enzymes and lignin-degrading auxiliary enzymes were upregulated in YK-624. This might explain the high degradation efficiency of YK-624. In addition, the genes involved in energy metabolism pathways, such as the TCA cycle, oxidative phosphorylation, lipid metabolism, carbon metabolism and glycolysis, were upregulated under ligninolytic conditions in YK-624.Conclusions In the present study, the first differential gene expression analysis of YK-624 under ligninolytic and nonligninolytic conditions was reported. The results obtained in this study indicated that YK-624 produces more energy- and lignin-degrading enzymes for more efficient lignin biodegradation.

Nutritional regulation of synthetic lignin (DHP) degradation by Phlebia (Merulius) tremellosa: effects of nitrogen

1991 ◽  
Vol 69 (1) ◽  
pp. 156-160 ◽  
Author(s):  
Ian D. Reid
Keyword(s):  
Energy Source ◽  
Key Words ◽  
Ammonium Chloride ◽  
Yeast Extract ◽  
Lignin Degradation ◽  
Synthetic Medium ◽  
Lignin Biodegradation ◽  
Nutritional Regulation

Supplementary nitrogen added to cultures of Phlebia tremellosa in a nitrogen-limited synthetic medium delayed the appearance of lignin-degrading activity. It also accelerated the consumption of the carbon (energy) source by the cultures, decreasing the amount of cosubstrate available to support lignin biodegradation. Ammonium chloride, glutamate, albumin, and yeast extract all had similar effects, with small differences in the timing and extent of the lignin degradation that they allowed. Key words: lignin biodegradation, cosubstrate, nitrogen, selectivity.

The influence of nutrient balance on lignin degradation by the white-rot fungus Phanerochaete chrysosporium

1979 ◽  
Vol 57 (19) ◽  
pp. 2050-2058 ◽  
Author(s):  
Ian D. Reid
Keyword(s):  
Phanerochaete Chrysosporium ◽  
Lignin Degradation ◽  
Nutrient Balance ◽  
White Rot ◽  
Phosphate Limitation ◽  
White Rot Fungus ◽  
Aspen Wood ◽  
Nitrogen Levels ◽  
Carbon:Nitrogen Ratio ◽  
Lignin Metabolism

The degradation by Phanerochaete chrysosporium of "natural" lignin in aspen wood, like synthetic lignin, was inhibited by nitrogen and stimulated by carbohydrate. Nitrogen delayed the appearance and reduced the level of ligninolytic activity and indirectly hastened its decline by accelerating depletion of the carbohydrate supply. The carbon:nitrogen ratio of the medium was a better predictor of lignin degradation than the absolute carbohydrate and nitrogen levels. Unlike nitrogen limitation, sulphate and phosphate limitation of growth did not stimulate lignin metabolism.

scholarly journals Applicability of Recombinant Laccases From the White-Rot Fungus Obba rivulosa for Mediator-Promoted Oxidation of Biorefinery Lignin at Low pH

2020 ◽  
Vol 8 ◽  
Author(s):  
Jussi Kontro ◽  
Riku Maltari ◽  
Joona Mikkilä ◽  
Mika Kähkönen ◽  
Miia R. Mäkelä ◽  
...  
Keyword(s):  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Reaction Conditions ◽  
Tempo Oxidation ◽  
Chemical Treatments ◽  
Mediator Systems ◽  
Phenolic Components ◽  
Lignin Model ◽  
Rich Side

Utilization of lignin-rich side streams has been a focus of intensive studies recently. Combining biocatalytic methods with chemical treatments is a promising approach for sustainable modification of lignocellulosic waste streams. Laccases are catalysts in lignin biodegradation with proven applicability in industrial scale. Laccases directly oxidize lignin phenolic components, and their functional range can be expanded using low-molecular-weight compounds as mediators to include non-phenolic lignin structures. In this work, we studied in detail recombinant laccases from the selectively lignin-degrading white-rot fungus Obba rivulosa for their properties and evaluated their potential as industrial biocatalysts for the modification of wood lignin and lignin-like compounds. We screened and optimized various laccase mediator systems (LMSs) using lignin model compounds and applied the optimized reaction conditions to biorefinery-sourced technical lignin. In the presence of both N–OH-type and phenolic mediators, the O. rivulosa laccases were shown to selectively oxidize lignin in acidic reaction conditions, where a cosolvent is needed to enhance lignin solubility. In comparison to catalytic iron(III)–(2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) oxidation systems, the syringyl-type lignin units were preferred in mediated biocatalytic oxidation systems.

Production of H 2 O 2 in Phanerochaete chrysosporium during lignin degradation

1987 ◽  
Vol 321 (1561) ◽  
pp. 455-459 ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Phanerochaete Chrysosporium ◽  
Essential Role ◽  
Lignin Degradation ◽  
White Rot ◽  
White Rot Fungus ◽  
Glucose Starvation ◽  
Methanol Induction ◽  
Catalysed Oxidation ◽  
Methanol Oxidase

Evidence in support of an essential role for H 2 O 2 in lignin degradation by the white-rot fungus Phanerochaete chrysosporium has been presented by several laboratories. H 2 O 2 is formed simultaneously with the ligninolytic system, and when it is degraded by catalase the lignin-degrading capacity is also reduced. We have now identified, purified and characterized a sugar-oxidizing enzyme that produces H 2 O 2 during glucose starvation in P. chrysosporium . The enzyme oxidizes glucose at the 2-carbon position to yield glucosone, but 5-n-gluconolactone and xylose are also oxidized at significant rates. Another H 2 O 2 -producing enzyme in P.chrysosporium , methanol oxidase, has also been identified, purified and characterized in this laboratory. Methanol is formed from the methoxyl groups in lignin. Hydrogen peroxide, necessary for further degradation of lignin, is formed by enzyme-catalysed oxidation of the lignin-derived methanol. Induction and repression of the H 2 O 2 -producing enzymes is discussed, as well as ways for the fungus to control the glucose level in its environment.

Synthesis of ethylene maleic anhydride copolymer containing fungicides and evaluation of their effect for wood decay resistance

Holzforschung ◽  
2008 ◽  
Vol 62 (4) ◽  
Author(s):  
George C. Chen
Keyword(s):  
Maleic Anhydride ◽  
Active Agent ◽  
Wood Decay ◽  
Decay Resistance ◽  
White Rot ◽  
White Rot Fungus ◽  
Dimethyl Formamide ◽  
Poly Ethylene ◽  
Maleic Anhydride Copolymer ◽  
Hydroxy Quinoline

Abstract The aim of the present study was to combat wood decay based on the approach controlled-release biocides from polymers. The possibility of introducing polymer-bonded fungicides into the cell lumens was investigated. The synthesis of ethylene maleic anhydride copolymer containing pentachlorophenol (penta) and 8-hydroxy quinoline (8HQ) in N, N dimethyl formamide is described. It was demonstrated that the penta-bonded acrylate is a poly(ethylene co-dipentachlorophenyl diacrylate), which has a disubstituted pentachlorophenyl group linked through two acrylate ester bonds. The reaction of ethylene maleic anhydride copolymer with 8-hydroxy quinoline leads to products containing 44.8% poly(ethylene co-8-hydroxy quinolinyl acrylate) and 55.2% of unreacted poly(ethylene co-maleic anhydride). Wood impregnated with the polymers described prevented decay by a brown- and white-rot fungus, even after water leaching. Wood treated with the fungicide pentachlorophenol (penta) alone prevented only decay by a brown-rot fungus. An advantage is that high loading of penta in polymer can be achieved. Moreover, there is a slow-release effect on the active agent due to hydrolysis of ester bonds. The decay resistance of wood treated with poly(ethylene co-8-quinolinyl acrylate) was similar to that of wood impregnated with 8-hydroxy quinoline.

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