scholarly journals Agaricales Mushroom Lignin Peroxidase: From Structure–Function to Degradative Capabilities

Antioxidants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1446
Author(s):  
María Isabel Sánchez-Ruiz ◽  
Iván Ayuso-Fernández ◽  
Jorge Rencoret ◽  
Andrés Manuel González-Ramírez ◽  
Dolores Linde ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
White Rot Fungi ◽  
2D Nmr ◽  
White Rot ◽  
Tryptophan Residue ◽  
Stopped Flow ◽  
Lignin Biodegradation ◽  
X Ray Crystallography ◽  
Reduction Potentials ◽  
Compound Ii

Lignin biodegradation has been extensively studied in white-rot fungi, which largely belong to order Polyporales. Among the enzymes that wood-rotting polypores secrete, lignin peroxidases (LiPs) have been labeled as the most efficient. Here, we characterize a similar enzyme (ApeLiP) from a fungus of the order Agaricales (with ~13,000 described species), the soil-inhabiting mushroom Agrocybe pediades. X-ray crystallography revealed that ApeLiP is structurally related to Polyporales LiPs, with a conserved heme-pocket and a solvent-exposed tryptophan. Its biochemical characterization shows that ApeLiP can oxidize both phenolic and non-phenolic lignin model-compounds, as well as different dyes. Moreover, using stopped-flow rapid spectrophotometry and 2D-NMR, we demonstrate that ApeLiP can also act on real lignin. Characterization of a variant lacking the above tryptophan residue shows that this is the oxidation site for lignin and other high redox-potential substrates, and also plays a role in phenolic substrate oxidation. The reduction potentials of the catalytic-cycle intermediates were estimated by stopped-flow in equilibrium reactions, showing similar activation by H2O2, but a lower potential for the rate-limiting step (compound-II reduction) compared to other LiPs. Unexpectedly, ApeLiP was stable from acidic to basic pH, a relevant feature for application considering its different optima for oxidation of phenolic and nonphenolic compounds.

Establishing molecular genetics for Phanerochaete chrysosporium

1987 ◽  
Vol 321 (1561) ◽  
pp. 475-483 ◽  
Keyword(s):  
Phanerochaete Chrysosporium ◽  
Complex Function ◽  
Strain Improvement ◽  
White Rot Fungi ◽  
Point Of View ◽  
Site Directed Mutagenesis ◽  
White Rot ◽  
General Strategy ◽  
Lignin Biodegradation ◽  
Control Of Expression

Genetics provides an approach to the analysis of the complex function of lignin biodegradation, through the isolation of mutants and the creation of gene libraries for the identification of genes and their products. However, white-rot fungi (for example, Phanerochaete chrysosporium ) have not so far been analysed from this point of view, and there is the challenge of establishing such genetics. P. chrysosporium is convenient experimentally because relatively few genes are switched on at the onset of ligninolytic activity. We describe the isolation of clones carrying genes expressed specifically in the ligninolytic phase, the development of a general strategy for mapping such clones, and the elucidation of the mating system of this organism. Another objective is the development of methods for transforming DNA into P. chrysosporium . This would allow the use of site-directed mutagenesis to analyse the functioning of ligninases, and the control of expression of the corresponding genes. The use of genetic crosses for strain improvement and the identification of components of the system are also discussed.

scholarly journals Peroxidase evolution in white-rot fungi follows wood lignin evolution in plants

2019 ◽  
Vol 116 (36) ◽  
pp. 17900-17905 ◽  
Author(s):  
Iván Ayuso-Fernández ◽  
Jorge Rencoret ◽  
Ana Gutiérrez ◽  
Francisco Javier Ruiz-Dueñas ◽  
Angel T. Martínez
Keyword(s):  
White Rot Fungi ◽  
Transient State ◽  
Analytical Techniques ◽  
Progressive Increase ◽  
White Rot ◽  
Stopped Flow ◽  
Syringyl Lignin ◽  
Time Calibration ◽  
Sequence Reconstruction ◽  
Catalytic Tryptophan

A comparison of sequenced Agaricomycotina genomes suggests that efficient degradation of wood lignin was associated with the appearance of secreted peroxidases with a solvent-exposed catalytic tryptophan. This hypothesis is experimentally demonstrated here by resurrecting ancestral fungal peroxidases, after sequence reconstruction from genomes of extant white-rot Polyporales, and evaluating their oxidative attack on the lignin polymer by state-of-the-art analytical techniques. Rapid stopped-flow estimation of the transient-state constants for the 2 successive one-electron transfers from lignin to the peroxide-activated enzyme (k2app and k3app) showed a progressive increase during peroxidase evolution (up to 50-fold higher values for the rate-limiting k3app). The above agreed with 2-dimensional NMR analyses during steady-state treatments of hardwood lignin, showing that its degradation (estimated from the normalized aromatic signals of lignin units compared with a control) and syringyl-to-guaiacyl ratio increased with the enzyme evolutionary distance from the first peroxidase ancestor. More interestingly, the stopped-flow estimations of electron transfer rates also showed how the most recent peroxidase ancestors that already incorporated the exposed tryptophan into their molecular structure (as well as the extant lignin peroxidase) were comparatively more efficient at oxidizing hardwood (angiosperm) lignin, while the most ancestral “tryptophanless” enzymes were more efficient at abstracting electrons from softwood (conifer) lignin. A time calibration of the ancestry of Polyporales peroxidases localized the appearance of the first peroxidase with a solvent-exposed catalytic tryptophan to 194 ± 70 Mya, coincident with the diversification of angiosperm plants characterized by the appearance of dimethoxylated syringyl lignin units.

scholarly journals Lignin Biodegradation in Pulp-and-Paper Mill Wastewater by Selected White Rot Fungi

Water ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 935 ◽  
Author(s):  
Stefania Costa ◽  
Davide Dedola ◽  
Simone Pellizzari ◽  
Riccardo Blo ◽  
Irene Rugiero ◽  
...  
Keyword(s):  
White Rot Fungi ◽  
Paper Mill ◽  
Pulp And Paper ◽  
White Rot ◽  
Lignin Biodegradation ◽  
Pulp And Paper Mill ◽  
Paper Mill Wastewater

scholarly journals Enhanced lignin biodegradation by consortium of white rot fungi: microbial synergistic effects and product mapping

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Tangwu Cui ◽  
Bo Yuan ◽  
Haiwei Guo ◽  
Hua Tian ◽  
Weimin Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Enzymatic Activity ◽  
Quantum Coherence ◽  
Lignin Degradation ◽  
Synergistic Effects ◽  
White Rot Fungi ◽  
White Rot ◽  
Lignin Biodegradation ◽  
Short Period ◽  
Product Mapping

Abstract Background As one of the major components of lignocellulosic biomass, lignin has been considered as the most abundant renewable aromatic feedstock in the world. Comparing with thermal or catalytic strategies for lignin degradation, biological conversion is a promising approach featuring with mild conditions and diversity, and has received great attention nowadays. Results In this study, a consortium of white rot fungi composed of Lenzites betulina and Trametes versicolor was employed to enhance the ligninolytic enzyme activity of laccase (Lac) and manganese peroxidase (MnP) under microbial synergism. The maximum enzymatic activity of Lac and MnP was individually 18.06 U mL−1 and 13.58 U mL−1 along with a lignin degradation rate of 50% (wt/wt), which were achieved from batch cultivation of the consortium. The activities of Lac and MnP obtained from the consortium were both improved more than 40%, as compared with monocultures of L. betulina or T. versicolor under the same culture condition. The enhanced biodegradation performance was in accordance with the results observed from scanning electron microscope (SEM) of lignin samples before and after biodegradation, and secondary-ion mass spectrometry (SIMS). Finally, the analysis of heteronuclear single quantum coherence (HSQC) NMR and gas chromatography–mass spectrometry (GC–MS) provided a comprehensive product mapping of the lignin biodegradation, suggesting that the lignin has undergone depolymerization of the macromolecules, side-chain cleavage, and aromatic ring-opening reactions. Conclusions Our results revealed a considerable escalation on the enzymatic activity obtained in a short period from the cultivation of the L. betulina or T. versicolor due to the enhanced microbial synergistic effects, providing a potential bioconversion route for lignin utilization.

Biodegradation of lignin

1995 ◽  
Vol 73 (S1) ◽  
pp. 1011-1018 ◽  
Author(s):  
Ian D. Reid
Keyword(s):  
Lignin Peroxidase ◽  
Manganese Peroxidase ◽  
Extracellular Enzymes ◽  
White Rot Fungi ◽  
Wood Decay ◽  
Brown Rot ◽  
Economic Consequences ◽  
White Rot ◽  
Lignin Biodegradation ◽  
Pulp Bleaching

Lignin is an aromatic polymer forming up to 30% of woody plant tissues, providing rigidity and resistance to biological attack. Because it is insoluble, chemically complex, and lacking in hydrolysable linkages, lignin is a difficult substrate for enzymatic depolymerization. Certain fungi, mostly basidiomycetes, are the only organisms able to extensively biodegrade it; white-rot fungi can completely mineralize lignin, whereas brown-rot fungi merely modify lignin while removing the carbohydrates in wood. Several oxidative and reductive extracellular enzymes (lignin peroxidase, manganese peroxidase, laccase, and cellobiose:quinone oxidoreductase) have been isolated from ligninolytic fungi; the role of these enzymes in lignin biodegradation is being intensively studied. Enzymatic combustion, a process wherein enzymes generate reactive intermediates, but do not directly control the reactions leading to lignin breakdown, has been proposed as the mechanism of lignin biodegradation. The economic consequences of lignin biodegradation include wood decay and the biogeochemical cycling of woody biomass. Efforts are being made to harness the delignifying abilities of white-rot fungi to aid wood and straw pulping and pulp bleaching. These fungi can also be used to degrade a variety of pollutants in wastewaters and soils, to increase the digestibility of lignocellulosics, and possibly to bioconvert lignins to higher value products. Key words: delignification, white-rot fungi, biobleaching, lignin peroxidase, manganese peroxidase, laccase.

scholarly journals Biobleaching of flax by degradation of lignin with laccase

BioResources ◽  
2007 ◽  
Vol 2 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Rossica I. Betcheva ◽  
Hristina A. Hadzhiyska ◽  
Neli V. Georgieva ◽  
Lubov K. Yotova
Keyword(s):  
White Rot Fungi ◽  
White Rot ◽  
Oxidative Enzymes ◽  
Lignin Biodegradation ◽  
Renewable Materials ◽  
Flax Fibers ◽  
Lignin Peroxidases

Research on lignin biodegradation has become of great interest, due to the fact that lignin is one of the most abundant renewable materials, next to cellulose. Lignin is also the substance that gives color to raw flax fibers. In order to bleach the flax and to keep its tenacity high enough for textile applications, it is necessary to remove the lignin and partially to preserve the pectin. Lignin and pectin are the main constituents of the layer which sticks the flax cells together within the multicellular technical fiber. White-rot fungi and their oxidative enzymes, laccases and peroxid-ases (lignin peroxidases and manganese peroxidases), are being applied for the biobleaching of papermaking pulp, thereby reducing the need for environmentally harmful chemicals. Some data also suggest that it is possible to use other phenolytic enzymes, such as pure laccase, for this purpose. The objective of the present work was to study the possibility of bleaching flax fibers by pure laccase and combined laccase peroxide treatment, aimed at obtaining fibers with high whiteness and well-preserved tenacity.

Effect of an electro-Fenton process on the biodegradation of lignin by Trametes versicolor

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8039-8050
Author(s):  
Jiahe Shen ◽  
Lipeng Hou ◽  
Haipeng Sun ◽  
Mingyang Hu ◽  
Lihua Zang ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Manganese Peroxidase ◽  
Trametes Versicolor ◽  
Lignin Degradation ◽  
White Rot Fungi ◽  
Maximum Growth ◽  
White Rot ◽  
Lignin Biodegradation ◽  
Fenton Process ◽  
Mycelium Growth

A synergistic effect was found between the electro-Fenton (E-Fenton) process and a white-rot enzyme (Trametes versicolor) system relative to the degradation of dealkaline lignin. The hydrogen peroxide produced by the E-Fenton process reacted with Fe2+ on the cathode to generate a large number of hydroxyl radicals. These hydroxyl radicals directly degraded various functional groups in lignin, which led to the quick initiation of lignin peroxidase (LiP) and manganese peroxidase (MnP) enzymatic hydrolysis and accelerated the progress of lignin biodegradation. In addition, the hydroxyl radicals produced by the Fenton reaction converted nonphenolic lignin into phenolic lignin, further promoting the ability of manganese peroxidase and laccase to degrade the lignin. Additionally, the Fe3+ secreted by white-rot fungi accelerated the regeneration of Fe2+ on the composite cathode, which sustained the lignin degradation system. In the synergistic system, mycelium growth was significantly improved, with the maximum growth amount reaching 2.3 g and the lignin degradation rate reaching 84.5%, the activity of the three enzymes increased with the increase of currents over 96 h. Among them, the activity of MnP increased significantly to 402 U/L.

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