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.

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.

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.

scholarly journals Production of Ligninolytic Enzymes by White-Rot FungusDatroniasp. KAPI0039 and Their Application for Reactive Dye Removal

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Pilanee Vaithanomsat ◽  
Waraporn Apiwatanapiwat ◽  
Oncheera Petchoy ◽  
Jirawate Chedchant
Keyword(s):  
Lignin Degradation ◽  
Reactive Dyes ◽  
Ligninolytic Enzymes ◽  
Reactive Dye ◽  
Inoculum Size ◽  
White Rot ◽  
White Rot Fungus ◽  
Reactive Black 5 ◽  
Reactive Blue 19 ◽  
Fungal Inoculum

This study focused on decolorization of 2 reactive dyes; Reactive Blue 19 (RBBR) and Reactive Black 5 (RB5), by selected white-rot fungusDatroniasp. KAPI0039. The effects of reactive dye concentration, fungal inoculum size as well as pH were studied. Samples were periodically collected for the measurement of color unit, Laccase (Lac), Manganese Peroxidase (MnP), and Lignin Peroxidase (LiP) activity. Eighty-six percent of 1,000 mg L−1RBBR decolorization was achieved by 2% (w/v)Datroniasp. KAPI0039 at pH 5. The highest Lac activity (759.81 UL−1) was detected in the optimal condition. For RB5,Datroniasp. KAPI0039 efficiently performed (88.01% decolorization) at 2% (w/v) fungal inoculum size for the reduction of 600 mg L−1RB5 under pH 5. The highest Lac activity (178.57 UL−1) was detected, whereas the activity of MnP and LiP was absent during this hour. The result, therefore, indicated thatDatroniasp. KAPI0039 was obviously able to breakdown both reactive dyes, and Lac was considered as a major lignin-degradation enzyme in this reaction.

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.

scholarly journals Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H2O2-Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System

2012 ◽  
Vol 78 (16) ◽  
pp. 5845-5854 ◽  
Author(s):  
Yang Yang ◽  
Fangfang Fan ◽  
Rui Zhuo ◽  
Fuying Ma ◽  
Yangmin Gong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Pichia Pastoris ◽  
Oxidative Damage ◽  
White Rot ◽  
Antioxidative System ◽  
White Rot Fungus ◽  
Laccase Gene ◽  
Content Type ◽  
Glutamylcysteine Synthetase

ABSTRACTLaccase is a copper-containing polyphenol oxidase that has great potential in industrial and biotechnological applications. Previous research has suggested that fungal laccase may be involved in the defense against oxidative stress, but there is little direct evidence supporting this hypothesis, and the mechanism by which laccase protects cells from oxidative stress also remains unclear. Here, we report that the expression of the laccase gene from white rot fungus inPichia pastoriscan significantly enhance the resistance of yeast to H2O2-mediated oxidative stress. The expression of laccase in yeast was found to confer a strong ability to scavenge intracellular H2O2and to protect cells from lipid oxidative damage. The mechanism by which laccase gene expression increases resistance to oxidative stress was then investigated further. We found that laccase gene expression inPichia pastoriscould increase the level of glutathione-based antioxidative activity, including the intracellular glutathione levels and the enzymatic activity of glutathione peroxidase, glutathione reductase, and γ-glutamylcysteine synthetase. The transcription of the laccase gene inPichia pastoriswas found to be enhanced by the oxidative stress caused by exogenous H2O2. The stimulation of laccase gene expression in response to exogenous H2O2stress further contributed to the transcriptional induction of the genes involved in the glutathione-dependent antioxidative system, includingPpYAP1,PpGPX1,PpPMP20,PpGLR1, andPpGSH1. Taken together, these results suggest that the expression of the laccase gene inPichia pastoriscan enhance the resistance of yeast to H2O2-mediated oxidative stress by stimulating the glutathione-based antioxidative system to protect the cell from oxidative damage.

Melanoidin-containing wastewaters induce selective laccase gene expression in the white-rot fungus Trametes sp. I-62

2008 ◽  
Vol 159 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Tania González ◽  
María Carmen Terrón ◽  
Susana Yagüe ◽  
Howard Junca ◽  
José María Carbajo ◽  
...  
Keyword(s):  
Gene Expression ◽  
White Rot ◽  
White Rot Fungus ◽  
Laccase Gene
Sign in / Sign up

Export Citation Format

Share Document