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

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.

1985 ◽  
Vol 63 (2) ◽  
pp. 337-339 ◽  
Author(s):  
Elmer L. Schmidt

Influences of eight saturated aliphatic acids (C5–C10, C12, and C16) on basidiospores of four isolates of wood-decay fungi (Poria tenuis and Trametes hispida, white rot fungi, and two isolates of the brown rot fungus Gloeophyllum trabeum) were observed in vitro. Spore responses after 24 h on malt extract agar containing 10, 102 or 103 ppm of each acid included normal germination, delay of germ tube emergence, vacuolation and degeneration of spore cytoplasm, and prevention of germ tube development without spore destruction. Acids of chain length C5–C10 prevented spore germination and killed spores of all fungi at concentrations of 20–50 ppm in media, whereas other acids tested were less active. Spore germination assay of decay fungi may prove useful as a screening tool to compare potency of wood preservatives.


2010 ◽  
Vol 76 (11) ◽  
pp. 3599-3610 ◽  
Author(s):  
Amber Vanden Wymelenberg ◽  
Jill Gaskell ◽  
Michael Mozuch ◽  
Grzegorz Sabat ◽  
John Ralph ◽  
...  

ABSTRACT Cellulose degradation by brown rot fungi, such as Postia placenta, is poorly understood relative to the phylogenetically related white rot basidiomycete, Phanerochaete chrysosporium. To elucidate the number, structure, and regulation of genes involved in lignocellulosic cell wall attack, secretome and transcriptome analyses were performed on both wood decay fungi cultured for 5 days in media containing ball-milled aspen or glucose as the sole carbon source. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a total of 67 and 79 proteins were identified in the extracellular fluids of P. placenta and P. chrysosporium cultures, respectively. Viewed together with transcript profiles, P. chrysosporium employs an array of extracellular glycosyl hydrolases to simultaneously attack cellulose and hemicelluloses. In contrast, under these same conditions, P. placenta secretes an array of hemicellulases but few potential cellulases. The two species display distinct expression patterns for oxidoreductase-encoding genes. In P. placenta, these patterns are consistent with an extracellular Fenton system and include the upregulation of genes involved in iron acquisition, in the synthesis of low-molecular-weight quinones, and possibly in redox cycling reactions.


2016 ◽  
Vol 82 (14) ◽  
pp. 4387-4400 ◽  
Author(s):  
Oleksandr Skyba ◽  
Dan Cullen ◽  
Carl J. Douglas ◽  
Shawn D. Mansfield

ABSTRACTIdentification of the specific genes and enzymes involved in the fungal degradation of lignocellulosic biomass derived from feedstocks with various compositions is essential to the development of improved bioenergy processes. In order to elucidate the effect of substrate composition on gene expression in wood-rotting fungi, we employed microarrays based on the annotated genomes of the brown- and white-rot fungi,Rhodonia placenta(formerlyPostia placenta) andPhanerochaete chrysosporium, respectively. We monitored the expression of genes involved in the enzymatic deconstruction of the cell walls of three 4-year-oldPopulus trichocarpa(poplar) trees of genotypes with distinct cell wall chemistries, selected from a population of several hundred trees grown in a common garden. The woody substrates were incubated with wood decay fungi for 10, 20, and 30 days. An analysis of transcript abundance in all pairwise comparisons highlighted 64 and 84 differentially expressed genes (>2-fold,P< 0.05) inP. chrysosporiumandP. placenta, respectively. Cross-fungal comparisons also revealed an array of highly differentially expressed genes (>4-fold,P< 0.01) across different substrates and time points. These results clearly demonstrate that gene expression profiles ofP. chrysosporiumandP. placentaare influenced by wood substrate composition and the duration of incubation. Many of the significantly expressed genes encode “proteins of unknown function,” and determining their role in lignocellulose degradation presents opportunities and challenges for future research.IMPORTANCEThis study describes the variation in expression patterns of two wood-degrading fungi (brown- and white-rot fungi) during colonization and incubation on three different naturally occurring poplar substrates of differing chemical compositions, over time. The results clearly show that the two fungi respond differentially to their substrates and that several known and, more interestingly, currently unknown genes are highly misregulated in response to various substrate compositions. These findings highlight the need to characterize several unknown proteins for catalytic function but also as potential candidate proteins to improve the efficiency of enzymatic cocktails to degrade lignocellulosic substrates in industrial applications, such as in a biochemically based bioenergy platform.


2020 ◽  
Vol 44 ◽  
Author(s):  
Carlos Garrido Pinheiro ◽  
Nadia Helena Bianchini ◽  
Alana Silveira Pavlack ◽  
Marlove Fátima Brião Muniz ◽  
Victor Dos Santos Barboza ◽  
...  

ABSTRACT Ergosterol is responsible for important functions in the fungal plasma membrane. The influence of fungitoxic agents on membrane ergosterol content is one of the most important mechanisms of antifungal action and its knowledge allows the generation of products that associate active compounds of different mechanisms, consequently improving the effectiveness of wood preservatives. Therefore, this study optimized a method for quantifying ergosterol in wood-decay fungi. The white-rot species selected were Ganoderma applanatum and Trametes versicolor, while the brown-rot were Gloeophyllum trabeum and Lentinus lepideus. Mycelial discs of each species were transferred to Petri dishes containing a cellophane-covered potato-dextrose-agar medium. Mycelia of each fungus were collected, weighed, and transferred to test tubes with 5 mL of 25% alcoholic potassium hydroxide. The tubes were vortexed for 5 min, subjected to ultrasound for 5 min, incubated at 85 °C for 4 h, followed by the addition of 2 mL of sterile distilled water and 5 mL of n-heptane and subsequent ultrasound shaking for 2 min. The n-heptane layer was analyzed by UV spectrophotometry between 230 and 300 ηm. The blank sample only contained n-heptane. The mycelia wet weight of the fungi ranged from 0.061 to 0.296 g. Ergosterol content was 0.007% for Lentinus lepideus and 0.004% for the other species. The absorbance was higher than the ones observed in the blank for all samples. The adapted method was efficient for ergosterol extraction.


Holzforschung ◽  
2004 ◽  
Vol 58 (6) ◽  
pp. 682-687 ◽  
Author(s):  
Jonathan S. Schilling ◽  
Jody Jellison

AbstractTwo brown-rot wood decay fungi,Fomitopsis pinicolaandMeruliporia incrassata, and the white-rot speciesPhanerochaete chrysosporiumwere grown for 4 weeks in liquid culture at 0.35, 0.70, 1.05, and 5.00 mM calcium (Ca) and 1.35 and 2.70 mM magnesium (Mg) concentrations. Soluble and total oxalate levels were quantified using a revised ion-exchange HPLC protocol developed specifically for resolving oxalate and other organic acid anions from medium components. Total oxalate concentrations in brown-rot filtrate were not significantly different among treatments; however, soluble oxalate decreased significantly with increasing Ca concentration. Higher Mg concentrations increased soluble oxalate levels only slightly. There was a significant decrease in medium pH at 5.00 mM Ca for all species, as well as an apparent increase in decarboxylation activity in brown-rot fungi. Total and soluble oxalate levels in the white-rot cultures were generally below detection for all treatments. The results show a significant influence of Ca on soluble oxalate concentrations not seen previously in the brown-rot speciesPostia placenta.


2000 ◽  
Vol 66 (11) ◽  
pp. 4725-4734 ◽  
Author(s):  
Claudia A. Jasalavich ◽  
Andrea Ostrofsky ◽  
Jody Jellison

ABSTRACT We have developed a DNA-based assay to reliably detect brown rot and white rot fungi in wood at different stages of decay. DNA, isolated by a series of CTAB (cetyltrimethylammonium bromide) and organic extractions, was amplified by the PCR using published universal primers and basidiomycete-specific primers derived from ribosomal DNA sequences. We surveyed 14 species of wood-decaying basidiomycetes (brown-rot and white-rot fungi), as well as 25 species of wood-inhabiting ascomycetes (pathogens, endophytes, and saprophytes). DNA was isolated from pure cultures of these fungi and also from spruce wood blocks colonized by individual isolates of wood decay basidiomycetes or wood-inhabiting ascomycetes. The primer pair ITS1-F (specific for higher fungi) and ITS4 (universal primer) amplified the internal transcribed spacer region from both ascomycetes and basidiomycetes from both pure culture and wood, as expected. The primer pair ITS1-F (specific for higher fungi) and ITS4-B (specific for basidiomycetes) was shown to reliably detect the presence of wood decay basidiomycetes in both pure culture and wood; ascomycetes were not detected by this primer pair. We detected the presence of decay fungi in wood by PCR before measurable weight loss had occurred to the wood. Basidiomycetes were identified to the species level by restriction fragment length polymorphisms of the internal transcribed spacer region.


1998 ◽  
Vol 44 (6) ◽  
pp. 575-581 ◽  
Author(s):  
Kent Nilsson ◽  
Jonny Bjurman

Cell wall chitin was determined in the mycelia of the brown rot fungus Neolentinus lepideus (Lentinus lepideus) and an isolate of the soft rot fungus Phialophora sp. to study the correlation to mycelial dry mass. The fungi were incubated as liquid cultures for three incubation periods at three temperatures in six nutrient media with varying levels and combinations of carbon and nitrogen. The glucosamine yield was found to be maximized by hydrolysis at 90°C for 48 h. The chitin content in the studied fungi varied from 8.3 to 39.8 μg.mg-1for N. lepideus and 7.7 to 46 μg.mg-1for the Phialophora isolate. The chitin concentration was remarkably constant, about 10 μg.mg-1, in mycelia growing on the low nitrogen malt extract medium. An experiment with wood blocks indicated that chitin may be a good marker for total fungal biomass production, including living and dead mycelia, in early stages of wood decay (dry weight loss <6%). At higher dry weight losses, the chitin content reaches a plateau or decreases despite continuing degradation as determined by the dry weight loss. The chitin content of visible mycelia growing on wood was determined for both fungi and found to be 19.1 and 12.9 μg.mg-1for N. lepideus and the Phialophora isolate, respectively.Key words: chitin, wood-decay fungi, utility poles, brown rot, soft rot, glucosamine, colorimetry.


Holzforschung ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 563-568 ◽  
Author(s):  
Frederick Green ◽  
Carol A. Clausen

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.


2020 ◽  
Vol 6 (2) ◽  
pp. 62
Author(s):  
Gerhard Gramss ◽  
Klaus-Dieter Voigt

Preparations of bacterial endospores and fungal conidia are applied in biocontrols, biocatalyses, and lignocellulose fermentations. The biocatalytic abilities of basidiospores from mushrooms of the order Agaricales are unknown. To assess their potential in colonizing recalcitrant substrates solely with their inherent resources, spores of the white-rot fungi Stropharia rugoso-annulata (Stru) and Kuehneromyces mutabilis (Kmt, Strophariaceae) were analyzed for surface-bound and internal total carbohydrates, phenols, proteins, minerals, and oxidoreductases to estimate their chemistry and the preconditions to transform the laccase substrates guaiacol and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) independent of external glucose and nitrogen. Surfaces of Stru/Kmt spores released (mg kg−1) hexoses, 7300/9700; phenols, >62/220; proteins, 21/168; and laccases, 42/0–0.15 µmol ABTS•+ kg−1 min−1 that mimicked oxidative activities of the resting spores. Milled-spore extracts contained pentoses, 96,600/6750; hexoses, 160,000/15,130; phenols, 452/767; protein, 12,600/924; true laccase, 688/0.30; and enzyme-protein-activating transition metals such as Cu in concentrations typical of wheat grains. Independent of external N and C supply, spores (<1‰) germinated in bideionized water, supported by their surface resources. Kmt spores germinated, too, at comparable rates in N-free solutions of glucose and the not immediately metabolizable ABTS and guaiacol. The release of proteins and oxidoreductase(s) by Kmt spores starting upon germination was higher in guaiacol-incubated idiophase- than in glucose-incubated trophophase-spores and led to the 3–4-fold formation of guaiacol polymerizates and ABTS•+. Constitutive aromatic ring-cleaving dioxygenases in the dormant spore that could be involved in the intrinsic metabolization of guaiacol were not detected. It is concluded that intrinsic resources enable (germinating) spores to release the highly efficient laccases of basidiomycetes and to transform aromatic compounds in the absence of sugar amendments. Spores show therefore plant seed-like autonomy in nutrient modification and acquisition during the early stages of the colonization of inert substrates.


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