Negative environmental impacts related to climate change and social pressure to raise the rotation age of forests contribute to the quality deterioration of harvested wood, including its ...decomposition by fungi. This paper presents the results of laboratory experiments investigating the decomposition of Norway spruce (Abies alba) and silver fir (Picea abies) wood by selected species of decay fungi: Hericium flagellum and Bondarzewia mesenterica (causing white rot) as well as Rhodofomes roseus (causing brown rot). The decay process affects wood density, elemental composition, net calorific value, as well as the amount and price of the energy contained in the wood. Wood density was measured conventionally using an electronic caliper and laboratory balance. Energy parameters were determined using elemental analyzer and combustion calorimeter. Wood decay was found to adversely affect energy content per unit of wood at a given volume, thus leading to higher prices per unit of energy. Over the 120 days of the experiment, wood parameters were not affected considerably by Hericium flagellum or Bondarzewia mesenterica. Of the three examined fungal species, Rhodofomes roseus caused the highest weight loss of wood and the greatest decrease in its oven-dry density (spruce - a decrease from 409 to 214 kg m−3; fir - a decrease from 420 to 306 kg m−3), unfavorably reducing energy content per 1 m3 of wood (spruce – decrease by 3.8 GJ m−3; fir – decrease by 2.3 GJ m−3) and raising the unit price of energy.
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The majority of wood decomposing fungi are mushroom-forming Agaricomycetes, which exhibit two main modes of plant cell wall decomposition: white rot, in which all plant cell wall components are ...degraded, including lignin, and brown rot, in which lignin is modified but not appreciably removed. Previous studies suggested that brown rot fungi tend to be specialists of gymnosperm hosts and that brown rot promotes gymnosperm specialization. However, these hypotheses were based on analyses of limited datasets of Agaricomycetes. Overcoming this limitation, we used a phylogeny with 1157 species integrating available sequences, assembled decay mode characters from the literature, and coded host specialization using the newly developed R package, rusda.
We found that most brown rot fungi are generalists or gymnosperm specialists, whereas most white rot fungi are angiosperm specialists. A six-state model of the evolution of host specialization revealed high transition rates between generalism and specialization in both decay modes. However, while white rot lineages switched most frequently to angiosperm specialists, brown rot lineages switched most frequently to generalism. A time-calibrated phylogeny revealed that Agaricomycetes is older than the flowering plants but many of the large clades originated after the diversification of the angiosperms in the Cretaceous.
Our results challenge the current view that brown rot fungi are primarily gymnosperm specialists and reveal intensive white rot specialization to angiosperm hosts. We thus suggest that brown rot associated convergent loss of lignocellulose degrading enzymes was correlated with host generalism, rather than gymnosperm specialism. A likelihood model of host specialization evolution together with a time-calibrated phylogeny further suggests that the rise of the angiosperms opened a new mega-niche for wood-decay fungi, which was exploited particularly well by white rot lineages.
Sibipiruna (Cenostigma pluviosum var. pelthophoroides) trees are common in the São Paulo city urban forest, but they may cause accidents when deteriorated by wood-decaying fungi due to trunk rupture ...and tree fall. Therefore, this study aimed to evaluate anatomical, physical, and mechanical changes in sibipiruna wood attacked by Ganoderma australe. Adult trees with basidiomata of this fungus and at imminent fall risk were macro and microscopically analyzed to investigate wood biodeterioration and resistance mechanisms (compartmentalization). Physical and mechanical tests (specific gravity, mechanism of resistance and static bending) were performed. In sibipiruna trees, degradation was observed in the heartwood, being more intense in the region near the pith and more extensive at the stem base, from where basidiomata were collected. Fungal attack was characterized as white pocket rot, i.e. non-selective to cell wall components, causing erosion of the S2 layer from the cell lumen. Decaying wood was also attacked by xylophagous insects, like the subterranean termite Coptotermes gestroi and wood-boring beetles. Wood compartmentalization was characterized by accumulation of extractives. White rot caused significant reductions in specific gravity, modulus of rupture and modulus of elasticity, which justify the rupture of trees when subjected to external forces, such as strong winds.
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•First report on lignocellulolytic activity and diversity of fungi from central Morocco.•Olive Mill Waste (OMW) is a suitable biomass for local biorefinery in Meknes region.•Fusaria ...isolates produce high and diversified lignocellulases using Consolidated Bioprocess.•Fusarium oxysporum (76) achieves 2.47 g.L−1 bioethanol production and 0.84 g.g−1 yield.•Bioethanol is maximally produced during the oxygen-limiting phase.
Meknes region is a Moroccan olive-processing area generating high amounts of non-valorized Olive Mill Waste (OMW). Fungi are natural decomposers producing varied enzyme classes and effectively contributing to the carbon cycle. However, structural complexity of biomass and modest performances of wild fungi are major limits for local biorefineries. The objective of current research is to assess the ability of local fungi for bioethanol production from OMW using Consolidated Bioprocessing (CBP). This is done by characterizing lignocellulolytic potential of six wood-decay and compost-inhabiting ascomycetes and selecting potent fermentation biocatalysts. High and diversified activities were expressed by Fusarium solani and Fusarium oxysporum: 9.36 IU. mL−1 and 2.88 IU. mL−1 total cellulase activity, 0.54 IU. mL−1 and 0.57 IU. mL−1 laccase activity, respectively, and 8.43 IU. mL−1 lignin peroxidase activity for the latter. F. oxysporum had maximum bioethanol production and yield of 2.47 g.L-1 and 0.84 g.g−1, respectively, qualifying it as an important bio-agent for single-pot local biorefinery.
Biological communities within living organisms are structured by their host's traits. How host traits affect biodiversity and community composition is poorly explored for some associations, such as ...arthropods within fungal fruit bodies. Using DNA metabarcoding, we characterized the arthropod communities in living fruit bodies of 11 wood-decay fungi from boreal forests and investigated how they were affected by different fungal traits. Arthropod diversity was higher in fruit bodies with a larger surface area-to-volume ratio, suggesting that colonization is crucial to maintain arthropod populations. Diversity was not higher in long-lived fruit bodies, most likely because these fungi invest in physical or chemical defences against arthropods. Arthropod community composition was structured by all measured host traits, namely fruit body size, thickness, surface area, morphology and toughness. Notably, we identified a community gradient where soft and short-lived fruit bodies harboured more true flies, while tougher and long-lived fruit bodies had more oribatid mites and beetles, which might reflect different development times of the arthropods. Ultimately, close to 75% of the arthropods were specific to one or two fungal hosts. Besides revealing surprisingly diverse and host-specific arthropod communities within fungal fruit bodies, our study provided insight into how host traits structure communities.
The study was aimed at testing environmental-friendly plant essential oils for their protecting efficiency of valuable woods against colonization by mould and wood-decay fungi. Sixteen essential oils ...were applied to Fagus orientalis and Pinus taeda wood samples by vacuum impregnation and infected with Aspergillus niger, Penicillium commune (moulds), Coniophora puteana (brown rot), Trametes versicolor (white rot), Chaetomium globosum (soft rot) and natural infection by airborne spores. Lavender oil, lemon grass oil and thyme oil were the most effective oils against all fungi tested.
Brown rot (BR) decay mechanisms employ carbohydrate-active enzymes (CAZymes) as well as a unique non-enzymatic chelator-mediated Fenton (CMF) chemistry to deconstruct lignocellulosic materials. ...Unlike white rot fungi, BR fungi lack peroxidases for lignin deconstruction, and also lack some endoglucanase/cellobiohydrolase activities. The role that the CMF mechanism plays in "opening up" the wood cell wall structure in advance of enzymatic action, and any interaction between CMF constituents and the selective CAZyme suite that BRs possess, is still unclear. Expression patterns for CMF redox metabolites and lytic polysaccharide monooxygenase (LPMO-AA9 family) genes showed that some LPMO isozymes were upregulated with genes associated with CMF at early stages of brown rot by
. In the structural studies, wood decayed by the
was compared to CMF-treated wood, or CMF-treated wood followed by treatment with either the early-upregulated LPMO or a commercial CAZyme cocktail. Structural modification of decayed/treated wood was characterized using small angle neutron scattering. CMF treatment produced neutron scattering patterns similar to that of the BR decay indicating that both systems enlarged the nanopore structure of wood cell walls to permit enzyme access. Enzymatic deconstruction of cellulose or lignin in raw wood samples was not achieved via CAZyme cocktail or LPMO enzyme action alone. CMF treatment resulted in depolymerization of crystalline cellulose as attack progressed from the outer regions of individual crystallites. Multiple pulses of CMF treatment on raw wood showed a progressive increase in the spacing between the cellulose elementary fibrils (EFs), indicating the CMF eroded the matrix outside the EF bundles, leading to less tightly packed EFs. Peracetic acid delignification treatment enhanced subsequent CMF treatment effects, and allowed both enzyme systems to further increase spacing of the EFs. Moreover, even after a single pulse of CMF treatment, both enzymes were apparently able to penetrate the cell wall to further increase EF spacing. The data suggest the potential for the early-upregulated LPMO enzyme to work in association with CMF chemistry, suggesting that
may have adopted mechanisms to integrate non-enzymatic and enzymatic chemistries together during early stages of brown rot decay.
•We identified Estonian strains of P. gigantea promising for biocontrol purposes.•Half of the P. gigantea isolates were virus-infected as revealed by RNA-Seq.•Partiti-, curvula-, ambi-like, aspi-like ...and “fusariviruses” were newly identified.
Coniferous forests, especially Norway spruce (Picea abies L.) stands, are threatened by root rot disease caused by Heterobasidion annosum sensu lato (Fr.) Bref. The basidiomycetous fungus, Phlebiopsis gigantea (Fr.) Donk, is used as a biocontrol agent against this pathogen in several countries. In Estonia, stump treatments are currently conducted using the Rotstop preparation, which consists of a P. gigantea strain isolated in Finland. However, for ecological reasons it would be preferable to use an indigenous biocontrol strain. In this study, we tested new strains of P. gigantea isolated from Norway spruce stumps in Estonia for their growth rate and competitive ability against H. parviporum and H. annosum, and identified P. gigantea strains promising for biocontrol purposes. As viruses may cause phenotypic debilitation in fungi, we analyzed the virome of these strains by high-throughput sequencing (RNA-Seq) and assessed whether the presence of mycoviruses affects their performance as compared to virus-free strains of P. gigantea. Viruses related to members of Partitiviridae and Curvulaviridae, as well as unclassified ambi-like, aspi-like and “fusariviruses” were identified for the first time in P. gigantea.
The phlebioid clade (Polyporales, Basidiomycota) accommodates numerous species of corticioid and polyporoid fungi of the Phanerochaetaceae, Irpicaceae, and Meruliaceae. The present study used ...morphological and phylogenetic approaches to revise the generic classification of the phlebioid clade and survey species diversity. The phylogenetic analyses were performed using sequences of multiple genes, including the nuc rDNA ITS1-5.8S-ITS2 (ITS), the D1-D2 domains of 28S rDNA (28S), the RNA polymerase II largest subunit (
rpb1
), the RNA polymerase II second largest subunit (
rpb2
), and the translation elongation factor 1-α (
tef1
). We overall recognize 57 genera including six new ones (
Alboefibula
,
Cremeoderma
,
Gelatinofungus
,
Luteochaete
,
Phanerochaetella
and
Quasiphlebia
). We describe 26 new species belonging to 15 genera (
Alboefibula bambusicola
,
A. gracilis
,
Crustodontia taiwanensis
,
Cytidiella albomarginata
,
Efibula matsuensis
,
E. turgida
,
E. subglobispora
,
Gelatinofungus brunneus
,
Hydnophlebia aurantia
,
H. crocata
,
Irpex lenis
,
Mycoaciella efibulata
,
Phanerochaete alpina
,
P. crystallina
,
P. guangdongensis
,
P. rhizomorpha
,
P. spadicea
,
P. subcarnosa
,
Phanerochaetella formosana
,
Phlebiopsis odontoidea
,
P. yushaniae
,
Quasiphlebia densa
,
Rhizochaete chinensis
,
Roseograndinia jilinensis
,
R. minispora
, and
Scopuloides allantoidea
), and present 18 new combinations belonging to 12 genera (
Cremeoderma unicum
,
Crustodontia nigrodontea
,
C. tongxiniana
,
Cytidiella albida
,
Efibula intertexta
,
Hydnophlebia alachuana
,
Irpex laceratus
,
I. latemarginatus
,
I. rosettiformis
,
Luteochaete subglobosa
,
Luteoporia lutea
,
Phanerochaetella angustocystidiata
,
P. exilis
,
P. leptoderma
,
P. xerophila
,
Phlebiopsis alba
,
Rhizochaete lutea
,
Scopuloides dimorpha
). Descriptions, illustrations and notes of new species and some new records are provided, as well as identification keys to genera of each family.
The aim of this study was to determine and quantify the wood‐decay fungi found on logs of forest tree species (beech, oak, hornbeam, Scots pine and fir) stored in log depots located in six different ...provinces in the Western Black Sea Region of Turkey. Additionally, it was aimed to determine the natural durability of some important wood species against the most commonly detected wood‐decay fungi. Eighteen families, 31 genera and 45 species belonging to the division Basidiomycota were detected; Antrodia crassa was identified for the first time in Turkey. The abundance of Panus neostrigosus, Polyporus meridionalis, Trametes hirsuta, T. versicolor and Stereum hirsutumincreased significantly with the holding time of the logs (r = 0.99, 0.87, 0.53, 0.57 and 0.78, respectively, p < 0.05). The majority of the fungal species were detected on logs stored in depots for 4–6 years (66%). The percentage of fungal species found on the logs with a holding time of three years or less was 29%, whereas the percentage for those detected on logs stored for seven or more years was 31%. Among the wood species, the greatest number of fungal species (29) and highest amount of fungi (2,539) occurred on beech wood. Natural durability tests showed that T. versicolor caused the greatest loss of wood mass, with an average of 23%. Field studies and natural durability tests performed in the laboratory showed that beech wood lost the most mass among the timber species studied.
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