scholarly journals Transcriptome analysis of the brown rot fungus Gloeophyllum trabeum during lignocellulose degradation

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243984
Author(s):  
Kiwamu Umezawa ◽  
Mai Niikura ◽  
Yuka Kojima ◽  
Barry Goodell ◽  
Makoto Yoshida
Keyword(s):  
Degradation Mechanism ◽  
Enzymatic Saccharification ◽  
Japanese Cedar ◽  
Brown Rot ◽  
Terpene Synthase ◽  
Lignocellulose Degradation ◽  
Substrate Selectivity ◽  
Gloeophyllum Trabeum ◽  
Wood Degradation ◽  
Brown Rot Fungi

Brown rot fungi have great potential in biorefinery wood conversion systems because they are the primary wood decomposers in coniferous forests and have an efficient lignocellulose degrading system. Their initial wood degradation mechanism is thought to consist of an oxidative radical-based system that acts sequentially with an enzymatic saccharification system, but the complete molecular mechanism of this system has not yet been elucidated. Some studies have shown that wood degradation mechanisms of brown rot fungi have diversity in their substrate selectivity. Gloeophyllum trabeum, one of the most studied brown rot species, has broad substrate selectivity and even can degrade some grasses. However, the basis for this broad substrate specificity is poorly understood. In this study, we performed RNA-seq analyses on G. trabeum grown on media containing glucose, cellulose, or Japanese cedar (Cryptomeria japonica) as the sole carbon source. Comparison to the gene expression on glucose, 1,129 genes were upregulated on cellulose and 1,516 genes were upregulated on cedar. Carbohydrate Active enZyme (CAZyme) genes upregulated on cellulose and cedar media by G. trabeum included glycoside hyrolase family 12 (GH12), GH131, carbohydrate esterase family 1 (CE1), auxiliary activities family 3 subfamily 1 (AA3_1), AA3_2, AA3_4 and AA9, which is a newly reported expression pattern for brown rot fungi. The upregulation of both terpene synthase and cytochrome P450 genes on cedar media suggests the potential importance of these gene products in the production of secondary metabolites associated with the chelator-mediated Fenton reaction. These results provide new insights into the inherent wood degradation mechanism of G. trabeum and the diversity of brown rot mechanisms.

Influence of carbon source on wood decay-associated gene expression in sequential hyphal zones of the brown rot fungus Gloeophyllum trabeum

2021 ◽  
Author(s):  
Kiwamu Umezawa ◽  
Shuji Itakura
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Carbon Source ◽  
Glycoside Hydrolase ◽  
Degradation Mechanism ◽  
Enzymatic Saccharification ◽  
Brown Rot ◽  
Gloeophyllum Trabeum ◽  
Brown Rot Fungi ◽  
Brown Rot Fungus

Abstract Brown rot fungi show a two-step wood degradation mechanism comprising oxidative radical-based and enzymatic saccharification systems. Recent studies have demonstrated that the brown rot fungus Rhodonia placenta expresses oxidoreductase genes ahead of glycoside hydrolase genes and spatially protects the saccharification enzymes from oxidative damage of the oxidoreductase reactions. This study aimed to assess the generality of the spatial gene regulation of these genes in other brown rot fungi and examine the effects of carbon source on the gene regulation. Gene expression analysis was performed on 14 oxidoreductase and glycoside hydrolase genes in the brown rot fungus Gloeophyllum trabeum, directionally grown on wood, sawdust-agar, and glucose-agar wafers. In G. trabeum, both oxidoreductase and glycoside hydrolase genes were expressed at higher levels in sections behind the wafers. The upregulation of glycoside hydrolase genes was significantly higher in woody substrates than in glucose, whereas the oxidoreductase gene expression was not affected by substrates.

scholarly journals The termite fungal cultivar Termitomyces combines diverse enzymes and oxidative reactions for plant biomass conversion

2021 ◽  
Author(s):  
Felix Schalk ◽  
Cene Gostinčar ◽  
Nina B. Kreuzenbeck ◽  
Benjamin H. Conlon ◽  
Elisabeth Sommerwerk ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Biomass Conversion ◽  
Degradation Mechanism ◽  
Oxidative Degradation ◽  
Ligninolytic Enzymes ◽  
Brown Rot ◽  
Dicarboxylic Acids ◽  
Lignocellulose Degradation ◽  
Redox Shuttle ◽  
Phenolic Polymer

AbstractMacrotermitine termites have domesticated fungi in the genus Termitomyces as their primary food source using pre-digested plant biomass. To access the full nutritional value of lignin-enriched plant biomass, the termite-fungus symbiosis requires the depolymerization of this complex phenolic polymer. While most previous work suggests that lignocellulose degradation is accomplished predominantly by the fungal cultivar, our current understanding of the underlying biomolecular mechanisms remains rudimentary. Here, we provide conclusive OMICs and activity-based evidence that Termitomyces partially depolymerizes lignocellulose through the combined actions of high-redox potential oxidizing enzymes (laccases, aryl-alcohol oxidases and a manganese peroxidase), the production of extracellular H2O2 and Fenton-based oxidative degradation, which is catalyzed by a newly described 2-methoxybenzoquinone/hydroquinone redox shuttle system and mediated by secreted chelating dicarboxylic acids. In combination, our approaches reveal a comprehensive depiction of how the efficient biomass degradation mechanism in this ancient insect agricultural symbiosis is accomplished through a combination of white- and brown-rot mechanisms.ImportanceFungus-growing termites have perfected the decomposition of recalcitrant plant biomass to access valuable nutrients by engaging in a tripartite symbiosis with complementary contributions from a fungal mutualist and a co-diversified gut microbiome. This complex symbiotic interplay makes them one of the most successful and important decomposers for carbon cycling in Old World ecosystems. To date, most research has focused on the enzymatic contributions of microbial partners to carbohydrate decomposition. Here we provide genomic, transcriptomic and enzymatic evidence that Termitomyces also employs redox mechanisms, including diverse ligninolytic enzymes and a Fenton-based hydroquinone-catalyzed lignin-degradation mechanism, to break down lignin-rich plant material. Insights into these efficient decomposition mechanisms open new sources of efficient ligninolytic agents applicable for energy generation from renewable sources.

scholarly journals Initial Rhodonia placenta Gene Expression in Acetylated Wood: Group-Wise Upregulation of Non-Enzymatic Oxidative Wood Degradation Genes Depending on the Treatment Level

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1117 ◽  
Author(s):  
Martina Kölle ◽  
Rebecka Ringman ◽  
Annica Pilgård
Keyword(s):  
Hydrolytic Enzymes ◽  
Oxidative Degradation ◽  
Brown Rot ◽  
Treatment Level ◽  
Wood Degradation ◽  
Weight Percentage ◽  
Brown Rot Fungi ◽  
Number Of Genes ◽  
Brown Rot Decay ◽  
Underlying Mechanisms

Acetylation has been shown to delay fungal decay, but the underlying mechanisms are poorly understood. Brown-rot fungi, such as Rhodonia placenta (Fr.) Niemelä, K.H. Larss. & Schigel, degrade wood in two steps, i.e., oxidative depolymerization followed by secretion of hydrolytic enzymes. Since separating the two degradation steps has been proven challenging, a new sample design was applied to the task. The aim of this study was to compare the expression of 10 genes during the initial decay phase in wood and wood acetylated to three different weight percentage gains (WPG). The results showed that not all genes thought to play a role in initiating brown-rot decay are upregulated. Furthermore, the results indicate that R. placenta upregulates an increasing number of genes involved in the oxidative degradation phase with increasing WPG.

Enzymatic saccharification of biologically pretreated Pinus densiflora using enzymes from brown rot fungi

2008 ◽  
Vol 106 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Jae-Won Lee ◽  
Ho-Yong Kim ◽  
Bon-Wook Koo ◽  
Don-Ha Choi ◽  
Mi Kwon ◽  
...  
Keyword(s):  
Pinus Densiflora ◽  
Enzymatic Saccharification ◽  
Brown Rot ◽  
Brown Rot Fungi

Changes of EPR Spectra of Wood Impregnated with Copper-Based Preservatives during Exposure to Several Wood-Rotting Fungi

Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 229-238 ◽  
Author(s):  
M. Humar ◽  
M. Petrič ◽  
F. Pohleven ◽  
M. Šentjurc ◽  
P. Kalan
Keyword(s):  
Schizophyllum Commune ◽  
White Rot Fungi ◽  
Brown Rot ◽  
White Rot ◽  
Gloeophyllum Trabeum ◽  
Nutrient Media ◽  
Paramagnetic Resonance ◽  
Copper Oxalate ◽  
Brown Rot Fungi ◽  
Electron Paramagnetic

SummaryThe tolerance of various fungi against copper was examined. For this purpose, we impregnated Norway spruce (Picea abies) specimens with two different aqueous solutions: copper(II) octanoate with ethanolamine or copper(II) sulfate (cCu= 1.0 × 10−2mol/l). Impregnated and unimpregnated test specimens were then exposed to brown rot fungiAntrodia vaillantiiandGloeophyllum trabeumor to white-rot fungiSchizophyllum communeandTrametes versicolor. After 2, 4, 6 and 12 weeks of exposure Electron Paramagnetic Resonance, Atomic Absorption Spectroscopy and mass loss measurements were performed. The results indicate thatA. vaillantii, G. trabeumandT. versicolortransform copper(II) sulfate in wood into non-soluble, and therefore non-toxic, copper oxalate. The intensity of this reaction depends on the amount of excreted oxalic acid and was the highest forA. vaillantiiand the lowest forT. versicolor. In the presence of ethanolamine, formation of insoluble copper oxalate was not possible and therefore, decay could not proceed. The major portion of copper remained in the wood and only minor amounts were in some cases translocated into nutrient media.

Degradation of chemically modified Scots pine (Pinus sylvestris L.) with Fenton reagent

Holzforschung ◽  
2015 ◽  
Vol 69 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Yanjun Xie ◽  
Zefang Xiao ◽  
Carsten Mai
Keyword(s):  
Fenton Reaction ◽  
Oxidative Degradation ◽  
Brown Rot ◽  
Fenton Reagent ◽  
Wood Degradation ◽  
Weight Percentage ◽  
Brown Rot Fungi ◽  
Minor Losses ◽  
Brown Rot Decay ◽  
Modified Wood

AbstractThe Fenton reaction is supposed to play a key role in the initial wood degradation by brown rot fungi. Wood was modified with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) and glutaraldehyde (GA) to various weight percentage gains in order to study if these types of modifications are able to reduce wood degradation by Fenton reagent. Veneers modified with higher concentrations (1.2 and 2.0 mol l-1) of both chemicals exhibited minor losses in mass and tensile strength during treatment with Fenton reagent, which shows restrained oxidative degradation by hydroxyl radicals. The decomposition rate of H2O2was lower in the Fenton solutions containing modified veneers than in those containing unmodified controls. More CO2evolved in systems containing unmodified veneers than in systems with modified veneers, indicating that modification protected wood from mineralisation. The reason for the enhanced resistance of modified wood to the Fenton reaction is attributed to impeded diffusion of the reagent into the cell wall rather than to inhibition of the Fenton reaction itself. The results show that wood modification with DMDHEU and GA is able to restrain the degradation of wood by the Fenton reaction and can explain why modified wood is more resistant to brown rot decay.

scholarly journals Design and synthesis of new benzofuran-1,2,3-triazole hybrid preservatives and the evaluation of their antifungal potential against white and brown-rot fungi

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7828-7843
Author(s):  
Fahimeh Abedinifar ◽  
S. Morteza F. Farnia ◽  
Seyyed Khalil Hosseinihashemi ◽  
Abbas Jalaligoldeh ◽  
Shahrbanoo Arabahmadi ◽  
...  
Keyword(s):  
Trametes Versicolor ◽  
Brown Rot ◽  
White Rot ◽  
Gloeophyllum Trabeum ◽  
Coniophora Puteana ◽  
Brown Rot Fungi ◽  
Design And Synthesis ◽  
Poria Placenta ◽  
Antifungal Potential ◽  
Antifungal Effects

A series of novel benzofuran-1,2,3-triazole hybrids were synthesized and investigated as fungicidal preservatives. The compounds were evaluated for their antifungal potential against white-rot (Trametes versicolor), dry brown-rot (Poria placenta), and wet brown-rot (Coniophora puteana and Gloeophyllum trabeum) fungi, at different concentrations (500 ppm and 1000 ppm). The tests of the final products (8a, 8b, 8c, 8d, 8e, 8f, and 8g) demonstrated that compound N-((1-(4-fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)benzofuran-2-carboxamide (8f) at a concentration of 500 ppm was the most active against wet brown-rot C. puteana (23.86% inhibition) and G. trabeum (47.16% inhibition) fungi. However, testing demonstrated that compounds 8a, 8b, 8c, 8d, and 8g at a concentration of 500 ppm did not exhibit acceptable antifungal effects against white-rot T. versicolor and dry brown-rot P. placenta fungi.

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