Iron-reducing capacity of low-molecular-weight compounds produced in wood by fungi

Holzforschung ◽  
2006 ◽  
Vol 60 (6) ◽  
pp. 630-636 ◽  
Author(s):  
Barry Goodell ◽  
Geoffrey Daniel ◽  
Jody Jellison ◽  
Yuhui Qian
Keyword(s):  
Enzymatic Degradation ◽  
Iron Reduction ◽  
Brown Rot ◽  
Soft Rot ◽  
Spot Test ◽  
White Rot ◽  
Low Molecular Weight ◽  
Decay Fungi ◽  
Brown Rot Fungi ◽  
Reducing Capacity

AbstractBirch and pine wood specimens were colonized by individual isolates of 12 brown-rot, 26 white-rot, six soft-rot and four blue (sap)-stain fungi. Homogenized wood was subsequently extracted in 75% ethyl acetate and centrifuged. The filtered extracts were analyzed for their iron-reducing capabilities using a ferrozine-based assay. Agar fungal cultures were also examined directly using a spot test for iron reduction. Extracts from wood colonized by brown-rot fungi showed significantly greater iron-reducing capability than extracts from wood colonized by white-rot or non-decay fungi. Results of the spot test ratings were highly variable, but in general the greatest color responses were associated with the brown-rot cultures. The ability of brown-rot fungi to produce compounds and/or modify the wood components that reduce iron is of relevance to the “chelator-mediated Fenton mechanism” that has been advanced as a theory for the non-enzymatic degradation of wood by brown-rot fungi.

Condensed conifer tannins as antifungal agents in liquid culture

Holzforschung ◽  
2013 ◽  
Vol 67 (7) ◽  
pp. 825-832 ◽  
Author(s):  
Anna-Kaisa Anttila ◽  
Anna Maria Pirttilä ◽  
Hely Häggman ◽  
Anni Harju ◽  
Martti Venäläinen ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Fungal Growth ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Wood Preservative ◽  
Soft Rot ◽  
White Rot ◽  
Wood Preservatives ◽  
Active Components ◽  
Brown Rot Fungi

Abstract In the last decades, many wood preservatives have been prohibited for their ecotoxicity. The present article is focusing on the conifer-derived condensed tannins as environment-friendly options for the substitution of artificial wood preservatives. Eight different tannin fractions were extracted from spruce cones, spruce barks, and pine cones. The parameters of tannin extraction, such as the methods of purification and concentration of active components in the extracts, have been investigated. The cone and bark extracts were tested for the growth inhibition of eight brown-rot fungi, three white-rot fungi, and four soft-rot fungi in liquid cultures. The cone tannins provided a more efficient fungal growth inhibition than bark tannins. Purification increased the antifungal properties of the extracts. The growth of brown-rot fungi was inhibited by the tannins already at low concentrations. However, the extracts were not effective against the white-rot or soft-rot fungi. More investigation is needed concerning the tannin source and the purification procedure of the extracts before tannins can be considered as an ecologically benign wood preservative.

Variation in germination percentage of basidiospores collected successively from wood decay fungi in culture

1983 ◽  
Vol 61 (1) ◽  
pp. 171-173 ◽  
Author(s):  
E. L. Schmidt ◽  
D. W. French
Keyword(s):  
Spore Germination ◽  
White Rot Fungi ◽  
Wood Decay ◽  
Brown Rot ◽  
Germination Percentage ◽  
White Rot ◽  
Malt Extract ◽  
Decay Fungi ◽  
Brown Rot Fungi ◽  
Wood Decay Fungi

Successive collections of basidiospores, produced in culture from the same hymenial areas of four species of wood decay fungi, were tested for spore germination percentage on malt extract agar under controlled conditions. Spores from white rot fungi retained high germination levels after 5 weeks of spore production, but germination averages for brown rot fungi decreased by more than 50%. Such variation should be considered in wood pathology research using spore germination bioassay.

scholarly journals Samanlarda Biyolojik Muamelelerle Lignoselüloz Kompleksin Sindirilebilirliğinin Artırılması

2017 ◽  
Vol 5 (13) ◽  
pp. 1704
Author(s):  
Aydan Atalar ◽  
Nurcan Çetinkaya
Keyword(s):  
Biological Treatment ◽  
Hydrolytic Enzymes ◽  
White Rot Fungi ◽  
Ligninolytic Enzymes ◽  
Brown Rot ◽  
Soft Rot ◽  
White Rot ◽  
Enzyme Treatment ◽  
Environmental Friendliness ◽  
Brown Rot Fungi

The efforts to break down the lignocellulosic complex found in the cell wall of straws, besides digestible cellulose and hemicellulose by rumen fermentation, improvement of straw digestibility by the degradation of indigestible lignin fraction of complex by using of biotechnological methods is one of the focus areas of animal nutritionists in recent years. Biological method sare prefer redover other methods due to the environmental friendliness. In the biological treatment methods of lignocellulosic complex, biodiversity of bacteria, enzymes and fungi gives opportunity to select lignin degrading species. Mycobacterium, Arthrobacter and Flavobacterium genre bacteria are used to degrade lignin by bacterial treatment. Lignocellulolytic enzymes isolated from different varieties of fungi are used in enzyme treatment. There are 3 genres of fungus that are white, Brown and soft rot in fungal treatments. Brown rot fungi prefer ably attack cellulose and hemicelluloses, but not lignin. White rot fungi attack the lignin and break up lignol bonds and aromatic ring. White rot fungi break down polysaccharides with hydrolytic enzymes such as cellulase, xylanase, and lignin with oxidative ligninolytic enzymes such as lignin peroxidase and laccase. Because of the fact that the microorganisms that can break down the lignocellulosic materials are the fungi and the cost is low, the application of white rot fungi is possible. In this paper, improvement the lignocellulosic comlex digestibility of straw by biological treatment with the advantage of biodiversity is discussed.

scholarly journals Samanlarda Biyolojik Muamelelerle Lignoselüloz Kompleksin Sindirilebilirliğinin Artırılması

2017 ◽  
Vol 5 (13) ◽  
pp. 1720 ◽  
Author(s):  
Aydan Atalar ◽  
Nurcan Çetinkaya
Keyword(s):  
Biological Treatment ◽  
Hydrolytic Enzymes ◽  
White Rot Fungi ◽  
Ligninolytic Enzymes ◽  
Brown Rot ◽  
Soft Rot ◽  
White Rot ◽  
Enzyme Treatment ◽  
Environmental Friendliness ◽  
Brown Rot Fungi

The efforts to break down the lignocellulosic complex found in the cell wall of straws, besides digestible cellulose and hemicellulose by rumen fermentation, improvement of straw digestibility by the degradation of indigestible lignin fraction of complex by using of biotechnological methods is one of the focus areas of animal nutritionists in recent years. Biological method sare prefer redover other methods due to the environmental friendliness. In the biological treatment methods of lignocellulosic complex, biodiversity of bacteria, enzymes and fungi gives opportunity to select lignin degrading species. Mycobacterium, Arthrobacter and Flavobacterium genre bacteria are used to degrade lignin by bacterial treatment. Lignocellulolytic enzymes isolated from different varieties of fungi are used in enzyme treatment. There are 3 genres of fungus that are white, Brown and soft rot in fungal treatments. Brown rot fungi prefer ably attack cellulose and hemicelluloses, but not lignin. White rot fungi attack the lignin and break up lignol bonds and aromatic ring. White rot fungi break down polysaccharides with hydrolytic enzymes such as cellulase, xylanase, and lignin with oxidative ligninolytic enzymes such as lignin peroxidase and laccase. Because of the fact that the microorganisms that can break down the lignocellulosic materials are the fungi and the cost is low, the application of white rot fungi is possible. In this paper, improvement the lignocellulosic comlex digestibility of straw by biological treatment with the advantage of biodiversity is discussed.

scholarly journals Syringic Acid Metabolism by Some White-rot, Soft-rot and Brown-rot Fungi

Microbiology ◽  
1984 ◽  
Vol 130 (10) ◽  
pp. 2457-2464 ◽  
Author(s):  
K.-E. Eriksson ◽  
J. K. Gupta ◽  
A. Nishida ◽  
M. Rao
Keyword(s):  
Acid Metabolism ◽  
Brown Rot ◽  
Soft Rot ◽  
Syringic Acid ◽  
White Rot ◽  
Brown Rot Fungi

Production of Polygalacturonase and Increase of Longitudinal Gas Permeability in Southern Pine by Brown-Rot and White-Rot Fungi

Holzforschung ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 563-568 ◽  
Author(s):  
Frederick Green ◽  
Carol A. Clausen
Keyword(s):  
Oxalic Acid ◽  
Liquid Culture ◽  
Gas Permeability ◽  
White Rot Fungi ◽  
Brown Rot ◽  
White Rot ◽  
Southern Pine ◽  
Decay Fungi ◽  
Brown Rot Fungi ◽  
Hydrolysis Of

SummaryHydrolysis of bordered and pinoid pits may be a key event during colonization of wood by decay fungi. Although pits are numerous, studies of pectin-hydrolyzing enzymes in wood decay fungi are scarce, probably because of the relatively low content (less than 4 %) of pectin in wood and because of the primary focus on understanding the degradation of lignified components. Endopolygalacturonase (endo- PG) activity was estimated by cup-plate assay and viscosity reduction of pectin from liquid cultures of fifteen brown-rot and eight white-rot basidiomycetous fungi using sodium polypectate as the carbon source. Oxalic acid was estimated in liquid culture and related to mycelial weight of each fungus. Changes in longitudinal gas permeability of southern pine cores exposed to selected decay fungi in liquid culture were measured to determine the extent of hydrolysis of bordered pits. Twelve of fifteen brown-rot and six of eight white-rot fungi tested were positive for at least one of the polygalacturonase test methods. Accumulation of oxalic acid was detected in thirteen of fifteen brown-rot isolates and none of the white-rot fungi tested. Gas permeability of pine cores increased approximately fourfold among brown-rot fungi tested and eighteenfold among white-rot fungi tested. Scanning electron microscopy revealed bordered pit membrane hydrolysis in cores colonized by white-rot fungi, but only torus damage, weakening and tearing of the pit membranes, was observed in cores exposed to brown-rot fungi. We conclude that both brown- and white-rot decay fungi have the enzymatic capacity to hydrolyze pectin, damage bordered pit membranes, and increase wood permeability during colonization and incipient decay.

Syringic acid metabolism by some white-rot, soft-rot, and brown-rot fungi

1984 ◽  
Vol 9 (4) ◽  
pp. 351-351
Author(s):  
K. Eriksson ◽  
J. K. Gupta ◽  
M. Rao ◽  
A. Nishida
Keyword(s):  
Acid Metabolism ◽  
Brown Rot ◽  
Soft Rot ◽  
Syringic Acid ◽  
White Rot ◽  
Brown Rot Fungi

scholarly journals Depolymerization and conversion of lignin to value-added bioproducts by microbial and enzymatic catalysis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Caihong Weng ◽  
Xiaowei Peng ◽  
Yejun Han
Keyword(s):  
Bond Cleavage ◽  
Enzymatic Catalysis ◽  
White Rot Fungi ◽  
Value Added ◽  
Brown Rot ◽  
Soft Rot ◽  
White Rot ◽  
Brown Rot Fungi ◽  
Cleavage Enzyme ◽  
Future Work

AbstractLignin, the most abundant renewable aromatic compound in nature, is an excellent feedstock for value-added bioproducts manufacturing; while the intrinsic heterogeneity and recalcitrance of which hindered the efficient lignin biorefinery and utilization. Compared with chemical processing, bioprocessing with microbial and enzymatic catalysis is a clean and efficient method for lignin depolymerization and conversion. Generally, lignin bioprocessing involves lignin decomposition to lignin-based aromatics via extracellular microbial enzymes and further converted to value-added bioproducts through microbial metabolism. In the review, the most recent advances in degradation and conversion of lignin to value-added bioproducts catalyzed by microbes and enzymes were summarized. The lignin-degrading microorganisms of white-rot fungi, brown-rot fungi, soft-rot fungi, and bacteria under aerobic and anaerobic conditions were comparatively analyzed. The catalytic metabolism of the microbial lignin-degrading enzymes of laccase, lignin peroxidase, manganese peroxidase, biphenyl bond cleavage enzyme, versatile peroxidase, and β-etherize was discussed. The microbial metabolic process of H-lignin, G-lignin, S-lignin based derivatives, protocatechuic acid, and catechol was reviewed. Lignin was depolymerized to lignin-derived aromatic compounds by the secreted enzymes of fungi and bacteria, and the aromatics were converted to value-added compounds through microbial catalysis and metabolic engineering. The review also proposes new insights for future work to overcome the recalcitrance of lignin and convert it to value-added bioproducts by microbial and enzymatic catalysis.

Growth behavior of wood-destroying fungi in chemically modified wood: wood degradation and translocation of nitrogen compounds

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Maja Bleckmann ◽  
Sarah Strohbusch ◽  
Christian Brischke ◽  
Susanne Bollmus ◽  
...  
Keyword(s):  
Protective Action ◽  
Treated Wood ◽  
Untreated Wood ◽  
Brown Rot ◽  
Decay Resistance ◽  
White Rot ◽  
Decay Fungi ◽  
Chemically Modified ◽  
Decay Tests ◽  
Modified Wood

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.

scholarly journals Evaluation of Compressive Strength of Decayed Wood in Magnolia obovata

2010 ◽  
Vol 36 (2) ◽  
pp. 81-85
Author(s):  
Kahoru Matsumoto ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
Naoto Habu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Early Stage ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Soft Rot ◽  
White Rot ◽  
Chemical Components ◽  
Cellulose Content ◽  
Magnolia Obovata ◽  
Weight Loss Ratio

To obtain the basic information needed to estimate the degree of decay from compressive strength measured using a Fractometer (CS), relationships between CS and the contents of chemical components were analyzed for Magnolia wood decayed by three types fungi (brown rot, white rot, and soft rot fungi) at various decay levels. Weight loss ratio was significantly, negatively correlated with CS in woods decayed by brown rot and white rot fungi. In addition, a relatively high correlation coefficient was recognized between CS and holocellulose or α-cellulose content, except for wood decayed by soft rot fungus. The results obtained showed that Fractometer can detect the decrease of CS at relatively early stage of decay.

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