scholarly journals The Pathogenic White-Rot Fungus Heterobasidion parviporum Responds to Spruce Xylem Defense by Enhanced Production of Oxalic Acid

2012 ◽  
Vol 25 (11) ◽  
pp. 1450-1458 ◽  
Author(s):  
Nina Elisabeth Nagy ◽  
Harald Kvaalen ◽  
Monica Fongen ◽  
Carl Gunnar Fossdal ◽  
Nicholas Clarke ◽  
...  

Pathogen challenge of tree sapwood induces the formation of reaction zones with antimicrobial properties such as elevated pH and cation content. Many fungi lower substrate pH by secreting oxalic acid, its conjugate base oxalate being a reductant as well as a chelating agent for cations. To examine the role of oxalic acid in pathogenicity of white-rot fungi, we conducted spatial quantification of oxalate, transcript levels of related fungal genes, and element concentrations in heartwood of Norway spruce challenged naturally by Heterobasidion parviporum. In the pathogen-compromised reaction zone, upregulation of an oxaloacetase gene generating oxalic acid coincided with oxalate and cation accumulation and presence of calcium oxalate crystals. The colonized inner heartwood showed trace amounts of oxalate. Moreover, fungal exposure to the reaction zone under laboratory conditions induced oxaloacetase and oxalate accumulation, whereas heartwood induced a decarboxylase gene involved in degradation of oxalate. The excess level of cations in defense xylem inactivates pathogen-secreted oxalate through precipitation and, presumably, only after cation neutralization can oxalic acid participate in lignocellulose degradation. This necessitates enhanced production of oxalic acid by H. parviporum. This study is the first to determine the true influence of white-rot fungi on oxalate crystal formation in tree xylem.

2009 ◽  
Vol 75 (12) ◽  
pp. 4069-4078 ◽  
Author(s):  
Ari M. Hietala ◽  
Nina E. Nagy ◽  
Arne Steffenrem ◽  
Harald Kvaalen ◽  
Carl G. Fossdal ◽  
...  

ABSTRACT In Norway spruce, a fungistatic reaction zone with a high pH and enrichment of phenolics is formed in the sapwood facing heartwood colonized by the white-rot fungus Heterobasidion parviporum. Fungal penetration of the reaction zone eventually results in expansion of this xylem defense. To obtain information about mechanisms operating upon heartwood and reaction zone colonization by the pathogen, hyphal growth and wood degradation were investigated using real-time PCR, microscopy, and comparative wood density analysis of naturally colonized trees with extensive stem decay. The hyphae associated with delignified wood at stump level were devoid of any extracellular matrix, whereas incipient decay at the top of decay columns was characterized by a carbohydrate-rich hyphal sheath attaching hyphae to tracheid walls. The amount of pathogen DNA peaked in aniline wood, a narrow darkened tissue at the colony border apparently representing a compromised region of the reaction zone. Vigorous production of pathogen conidiophores occurred in this region. Colonization of aniline wood was characterized by hyphal growth within polyphenolic lumen deposits in tracheids and rays, and the hyphae were fully encased in a carbohydrate-rich extracellular matrix. Together, these data indicate that the interaction of the fungus with the reaction zone involves a local concentration of fungal biomass that forms an efficient translocation channel for nutrients. Finally, the enhanced production of the hyphal sheath may be instrumental in lateral expansion of the decay column beyond the reaction zone boundary.


1991 ◽  
Vol 24 (3-4) ◽  
pp. 189-198 ◽  
Author(s):  
V. P. Lankinen ◽  
M. M. Inkeröinen ◽  
J. Pellinen ◽  
A. I. Hatakka

Decrease of adsorbable organic chlorine (AOX) is becoming the most important criterion for the efficiency of pulp mill effluent treatment in the 1990s. Two methods, designated MYCOR and MYCOPOR which utilize the white-rot fungus Phanerochaete chrysosporium have earlier been developed for the color removal of pulp mill effluents, but the processes have also a capacity to decrease the amount of chlorinated organic compounds. Lignin peroxidases (ligninases) produced by P. chrvsosporium may dechlorinate chlorinated phenols. In this work possibilities to use selected white-rot fungi in the treatment of E1-stage bleach plant effluent were studied. Phlebia radiata. Phanerochaete chrvsosporium and Merulius (Phlebia) tremellosus were compared in shake flasks for their ability to produce laccase, lignin peroxidase(s) and manganese-dependent peroxidase(s) and to remove color from a medium containing effluent. Softwood bleaching effluents were treated by carrier-immobilized P. radiata in 2 1 bioreactors and a 10 1 BiostatR -fermentor. Dechlorination was followed using Cl ion and AOX determinations. All fungi removed the color of the effluent. In P. radiata cultivations AOX decrease was ca. 4 mg l−1 in one day. Apparent lignin peroxidase activities as determined by veratryl alcohol oxidation method were negligible or zero in a medium with AOX content of ca. 60 mg l−1, prepared using about 20 % (v/v) of softwood effluent. However, the purification of extracellular enzymes implied that large amounts of lignin peroxidases were present in the medium and, after the purification, in active form. Enzyme proteins were separated using anion exchange chromatography, and they were further characterized by electrophoresis (SDS-PAGE) to reveal the kind of enzymes that were present during AOX decrease and color removal. The most characteristic lignin peroxidase isoenzymes in effluent media were LiP2 and LiP3.


2018 ◽  
Vol 14 (4) ◽  
pp. 721-726
Author(s):  
Nguyen Thi Hong Lien ◽  
Nguyen Van Hieu ◽  
Luong Thi Hong ◽  
Hy Tuan Anh ◽  
Phan Thi Hong Thao

Wood-rotting fungi represent an important component of forest ecosystems. Among them, white-rot fungi are the most efficient lignin degraders. Biopulping using white-rot fungi in pretreatment of the materials, is one of the solutions to overcome disadvantages of traditional production methods. Today, the isolation and screening of lignin degrading fungi capable for application in biopulping are of keen interest in Vietnam. The use of non–wood, plant fibres in pulp and paper industry, special, agricultural residuces such as rice and wheat straw, sugarcane baggase, cornstalks etc is the new production toward, potential, serving sustainable development. The fungus CP9, which possessed high ligninolytic activity, was identified and studied in pretreatment of rice straw for biopulping. The fruiting bodies of strain CP9 were effuse on trunk. The hymenium was porous and brown white with short tubes, the white mycelia penetrated wood block. The colony was off-white, blossom, irregularly circular. The mycelia were thick and closely bound together. Beside lignin, this fungus could degrade other substrates such as casein, carboxymethyl cellulose and starch. Biological and morphological characteristics of the fungus CP9 suggested its placement in subdivision Basidiomycota. Combined with the results of phylogenetic analysis, which showed 99% similarity of the fungus with species Leiotrametes lactinea, our strain was named as Leiotrametes lactinea CP9. This fungus could grow well on rice straw under solid state fermentation. Pretreatment of rice straw using L. lactinea CP9 was based on the activity of fungal lignin peroxidase and laccase. After 20 days, the residual enzyme activity was of 21.6 and 18.4 nkat/g material for lignin peroxidase and laccase, respectively. Pretreatment significantly improved the quality of straw, as lignin loss of 38% while cellulosic fibers were comparatively well preserved.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3797-3807
Author(s):  
Magdah Ganash ◽  
Tarek M. Abdel Ghany ◽  
Mohamed A. Al Abboud ◽  
Mohamed M. Alawlaqi ◽  
Husam Qanash ◽  
...  

Lignocellulolytic white-rot fungi allow the bioconversion of agricultural wastes into value-added products that are used in a myriad of applications. The aim of this work was to use corn residues (Zea mays L.) to produce valuable products under solid-state fermentation (SSF) with Pleurotus ostreatus. White-rot fungus P. ostreatus was isolated from maize silage (MS) and thereafter it was inoculated on MS as substrate and compared with maize stover (MSt) and maize cobs (MC) to determine the best lignocellulosic substrate for the production of lignocellulolytic enzymes and extracellular protein. The MS gave the highest productivity of CMCase (368.2 U/mL), FPase (170.5 U/mL), laccase (11.4 U/mL), and MnPase (6.6 U/mL). This is compared to productivity on MSt of 222 U/mL, 50.2 U/mL, 4.55 U/mL, and 2.57 U/mL, respectively; and productivity on MC at the same incubation period as 150.5 U/mL, 48.2 U/mL, 3.58 U/mL, and 2.5 U/mL, respectively. The levels of enzyme production declined with increasing incubation period after 15 and 20 days using MS and MC, respectively, as substrates. Maximum liberated extracellular protein content (754 to 878 µg/mL) was recorded using MS, while a low amount (343 to 408 µg/mL) was liberated with using MSt and MC.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
K. Y. Usha ◽  
K. Praveen ◽  
B. Rajasekhar Reddy

The white rot fungi Stereum ostrea displayed a wide diversity in their response to supplemented inducers, surfactants, and copper sulphate in solid state fermentation. Among the inducers tested, 0.02% veratryl alcohol increased the ligninolytic enzyme production to a significant extent. The addition of copper sulphate at 300 μM concentration has a positive effect on laccase production increasing its activity by 2 times compared to control. Among the surfactants, Tween 20, Tween 80, and Triton X 100, tested in the studies, Tween 80 stimulated the production of ligninolytic enzymes. Biosorption of dyes was carried out by using two lignocellulosic wastes, rice bran and wheat bran, in 50 ppm of remazol brilliant blue and remazol brilliant violet 5R dyes. These dye adsorbed lignocelluloses were then utilized for the production of ligninolytic enzymes in solid state mode. The two dye adsorbed lignocelluloses enhanced the production of laccase and manganese peroxidase but not lignin peroxidase.


Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 885 ◽  
Author(s):  
Casado-Sanz ◽  
Silva-Castro ◽  
Ponce-Herrero ◽  
Martín-Ramos ◽  
Martín-Gil ◽  
...  

There is growing interest in the development of non-toxic, natural wood preservation agents to replace conventional chemicals. In this paper, the antifungal activities of silver nanoparticles, chitosan oligomers, and propolis ethanolic extract were evaluated against white-rot fungus Trametes versicolor (L.) Lloyd, with a view to protecting Populus spp. wood. In order to create a more realistic in-service type environment, the biocidal products were assessed according to EN:113 European standard, instead of using routine in vitro antimicrobial susceptibility testing methods. Wood blocks were impregnated with the aforementioned antifungal agents by the vacuum-pressure method in an autoclave, and their biodeterioration was monitored over 16 weeks. The results showed that treatments based on silver nanoparticles, at concentrations ranging from 5 to 20 ppm, presented high antifungal activity, protecting the wood from fungal attack over time, with weight losses in the range of 8.49% to 8.94% after 16 weeks, versus 24.79% weight loss in the control (untreated) samples. This was confirmed by SEM and optical microscopy images, which showed a noticeably higher cell wall degradation in control samples than in samples treated with silver nanoparticles. On the other hand, the efficacy of the treatments based on chitosan oligomers and propolis gradually decreased over time, which would be a limiting factor for their application as wood preservatives. The nanometal-based approach is thus posed as the preferred choice for the industrial treatment of poplar wood aimed at wood-based engineering products (plywood, laminated veneer lumber, cross-laminated timber, etc.).


Holzforschung ◽  
1999 ◽  
Vol 53 (3) ◽  
pp. 247-252 ◽  
Author(s):  
M.J. Martínez-Inigo ◽  
P. Immerzeel ◽  
A. Gutierrez ◽  
J.C. del Río ◽  
R. Sierra-Alvarez

SummaryThe fungal degradation of lipophilic extractives in sapwood and heartwood from Scots pine (Pinus sylvestris) was studied. In sapwood, the white rot fungi,Bjerkanderasp. andFunalia trogii, removed higher amounts of extractives than the sapstain strains,Ophiostoma ainoaeandCeratocystis allantospora. Triglycerides, long chain fatty acids, steryl esters and waxes in pine sapwood were almost completely degraded by all the fungi. Sterols and resin acids were also extensively degraded by the white rot strains; however, these components were not or only poorly removed by the sapstain fungi. The removal of total extractives by all the fungal strains was higher in sapwood as compared to heartwood. The highly concentrated extractive fraction in pine heartwood mainly consists of resin acids. As observed in sapwood, sapstain were also poorly effective in the degradation of the resin acids present in heartwood. The fungal degradation of heartwood extractives was not only limited by the degradative ability of the various test microorganisms, but also by the inhibitory effect exerted by the extractive fraction. The white rot fungusF. trogiiwas particularly inhibited on heartwood.Bjerkanderasp. showed a higher tolerance to toxic extractives and was the most efficient fungus in degrading extractive constituents in both Scots pine heartwood and sapwood. Therefore,Bjerkanderasp. strain BOS55 should be considered as a potential agent for pitch control in pulp and paper manufacture.


Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Jonathan S. Schilling ◽  
Kaitlyn M. Bissonnette

AbstractWood-degrading fungi commonly grow in contact with calcium (Ca)-containing building materials and may import Ca and iron (Fe) from soil into forest woody debris. For brown rot fungi, imported Ca2+may neutralize oxalate, while Fe3+may facilitate Fenton-based degradation mechanisms. We previously demonstrated, in two independent trials, that degradation of spruce by wood-degrading fungi was not promoted when Ca or Fe were imported from gypsum or metallic Fe, respectively. Here, we tested pine wood with lower endogenous Ca than the spruce blocks used in prior experiments, and included a pure gypsum treatment and one amended with 1% with FeSO4. Electron microscopy with microanalysis verified that brown rot fungiSerpula himantioidesandGloeophyllum trabeumand the white rot fungusIrpex lacteusgrew on gypsum and produced iron-free Ca-oxalate crystals away from the gypsum surface. Wood cation analysis verified significant Fe import by both brown rot isolates in Fe-containing treatments. Wood degradation was highest in Fe-gypsum-containing treatments for all three fungi, although only wood degraded byI. lacteushad significant Ca import. We suggest that Fe impurities may not exacerbate brown rot, and that both brown and white rot fungi may utilize Ca-containing materials.


1996 ◽  
Vol 42 (9) ◽  
pp. 881-895 ◽  
Author(s):  
Martin V. Dutton ◽  
Christine S. Evans

Oxalate secretion by fungi provides many advantages for their growth and colonization of substrates. The role of oxalic acid in pathogenesis is through acidification of host tissues and sequestration of calcium from host cell walls. The formation of calcium oxalate crystals weakens the cell walls, thereby allowing polygalacturonase to effect degradation more rapidly in a synergistic response. There is good correlation between pathogenesis, virulence, and oxalic acid secretion. Solubility of soil nutrients is achieved by soil-living species, when cations freed by oxalate diffusing in clay layers increases the effective solubility of Al and Fe. Oxalate retained in hyphal mats of mycorrhizal species increases phosphate and sulphate availability. The formation of calcium oxalate crystals provides a reservoir of calcium in the ecosystem. The ability of oxalate to bind divalent cations permits detoxification of copper, particularly evident in wood preserved with copper salts. Oxalate plays a unique role in lignocellulose degradation by wood-rotting basidiomycetes, acting as a low molecular mass agent initiating decay. In addition, in white-rot fungi oxalate acts as a potential electron donor for lignin-peroxidase catalysed reduction and chelates manganese, allowing the dissolution of Mn3+from the manganese–enzyme complex and thus stimulating extracellular manganese peroxidase activity. The biosynthesis and degradation of oxalate are discussed.Key words: oxalic acid, calcium oxalate, pathogenicity, fungi.


Sign in / Sign up

Export Citation Format

Share Document