The effect of CaCl2 on growth rate, wood decay and oxalic acid accumulation in Serpula lacrymans and related brown-rot fungi

Holzforschung ◽  
2006 ◽  
Vol 60 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Anne Christine Steenkjær Hastrup ◽  
Bo Jensen ◽  
Carol Clausen ◽  
Frederick Green III

AbstractThe dry rot fungus,Serpula lacrymans, is one of the most destructive copper-tolerant fungi causing timber decay in buildings in temperate regions. Calcium and oxalic acid have been shown to play important roles in the mechanism of wood decay. The effect of calcium on growth and decay was evaluated for 12 strains ofS. lacrymansand compared to five brown-rot fungi. This was done by treating copper citrate (CC)-treated Southern yellow pine (SYP) wood with a CaCl2solution and estimating the decay rate and amount of soluble oxalic acid in an ASTM soil block test. Decay byS. lacrymanswas found to be significantly inhibited by treatment with CaCl2in the presence of copper. In addition, calcium showed no effect on two strains ofS. lacrymansand oneSerpula himantioidesstrain in non-copper-treated SYP wood blocks. The growth rate ofS. lacrymanswas not affected on malt extract agar containing CaCl2. In summary, a marked decrease was observed in the decay capacity ofS. lacrymansin pine treated with CC+CaCl2. The amount of soluble oxalic acid was measured in CC-treated blocks and blocks also treated with CaCl2. Of the comparative brown-rot fungi, bothAntrodia vaillantii(TFFH 294) andPostia placenta(Mad 698) displayed notable wood decay despite CaCl2treatment, while the remaining strains were inhibited.

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.


2016 ◽  
Vol 113 (39) ◽  
pp. 10968-10973 ◽  
Author(s):  
Jiwei Zhang ◽  
Gerald N. Presley ◽  
Kenneth E. Hammel ◽  
Jae-San Ryu ◽  
Jon R. Menke ◽  
...  

Wood-degrading brown rot fungi are essential recyclers of plant biomass in forest ecosystems. Their efficient cellulolytic systems, which have potential biotechnological applications, apparently depend on a combination of two mechanisms: lignocellulose oxidation (LOX) by reactive oxygen species (ROS) and polysaccharide hydrolysis by a limited set of glycoside hydrolases (GHs). Given that ROS are strongly oxidizing and nonselective, these two steps are likely segregated. A common hypothesis has been that brown rot fungi use a concentration gradient of chelated metal ions to confine ROS generation inside wood cell walls before enzymes can infiltrate. We examined an alternative: that LOX components involved in ROS production are differentially expressed by brown rot fungi ahead of GH components. We used spatial mapping to resolve a temporal sequence inPostia placenta, sectioning thin wood wafers colonized directionally. Among sections, we measured gene expression by whole-transcriptome shotgun sequencing (RNA-seq) and assayed relevant enzyme activities. We found a marked pattern of LOX up-regulation in a narrow (5-mm, 48-h) zone at the hyphal front, which included many genes likely involved in ROS generation. Up-regulation of GH5 endoglucanases and many other GHs clearly occurred later, behind the hyphal front, with the notable exceptions of two likely expansins and a GH28 pectinase. Our results support a staggered mechanism for brown rot that is controlled by differential expression rather than microenvironmental gradients. This mechanism likely results in an oxidative pretreatment of lignocellulose, possibly facilitated by expansin- and pectinase-assisted cell wall swelling, before cellulases and hemicellulases are deployed for polysaccharide depolymerization.


IAWA Journal ◽  
1993 ◽  
Vol 14 (2) ◽  
pp. 127-138 ◽  
Author(s):  
W. Wayne Wilcox

Early stages of decay by two brown-rot fungi in two woods were studied by light and scanning electron microscopy. The earliest diagnostic feature to appear was hyphae in the earlywood lumina. The earliest effect on cell walls was the loss of birefringence in the earlywood; Poria placenta (syn. Postia placenta) caused this loss at the earliest stage of decay observed, in both Douglas-fir and white fir, while Gloeophyllum trabeum caused significant weight loss before loss of birefringence was visible. Attack on the latewood progressed from the earlywood, and was different in pattern among the wood/fungus combinations. Hyphal and bore hole diameter increased throughout the early progression of decay and would be useful in evaluating the stage of decay, if the starting diameter of hyphae could be determined. Separation between cells was not observed until moderate stages of decay and, therefore, was not useful in diagnosing early stages of decay.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gerald N. Presley ◽  
Bongani K. Ndimba ◽  
Jonathan S. Schilling

Sweet sorghum is a promising crop for a warming, drying African climate, and basic information is lacking on conversion pathways for its lignocellulosic residues (bagasse). Brown rot wood-decomposer fungi use carbohydrate-selective pathways that, when assessed on sorghum, a grass substrate, can yield information relevant to both plant biomass conversion and fungal biology. In testing sorghum decomposition by brown rot fungi (Gloeophyllum trabeum,Serpula lacrymans), we found thatG. trabeumreadily degraded sorghum, removing xylan prior to removing glucan.Serpula lacrymans, conversely, caused little decomposition. Ergosterol (fungal biomarker) and protein levels were similar for both fungi, butS. lacrymansproduced nearly 4x lower polysaccharide-degrading enzyme specific activity on sorghum thanG. trabeum, perhaps a symptom of starvation. Linking this information to genome comparisons including other brown rot fungi known to have a similar issue regarding decomposing grasses(Postia placenta, Fomitopsis pinicola)suggested that a lack of CE 1 feruloyl esterases as well as low xylanase activity inS. lacrymans(3x lower than inG. trabeum) may hinderS. lacrymans,P. placenta,andF. pinicolawhen degrading grass substrates. These results indicate variability in brown rot mechanisms, which may stem from a differing ability to degrade certain lignin-carbohydrate complexes.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Liselotte De Ligne ◽  
Jan Van den Bulcke ◽  
Jan M. Baetens ◽  
Bernard De Baets ◽  
Gang Wang ◽  
...  

AbstractThe effect of fungicidal components in wood has been known for ages, yet there is no method to assess the impact of such components on the durability of a wood species, as compared to other material characteristics that influence decay. In this paper, the importance of fungicidal effects on the natural durability of 10 wood species is assessed in relation to other decay-influencing factors with a new test, the so-called ‘paste test’. By comparing results from this test with the ‘mini-block test’, on both heartwood and leached sapwood, insight is gained into the significance of fungicidal components on the one hand and other material characteristics on the other hand. The durability of species such as Prunus avium was attributed mainly to fungicidal components. For species such as Pterocarpus soyauxii, durability seemed to be an effect of both fungicidal components and moisture-regulating components, while the latter seemed to be of main importance in regulating the decay of Aucoumea klaineana and Entandrophragma cylindricum. Wood-anatomical features, such as the parenchyma content (in case of brown rot fungi) and the vessel-fiber ratio, possibly affect degradation as well. This work shows that fungicidal components are not always of major importance for the durability of a wood species. The authors hereby emphasize the importance of moisture-regulating components and wood anatomy on the durability of wood.


2010 ◽  
Vol 76 (7) ◽  
pp. 2091-2097 ◽  
Author(s):  
Dongsheng Wei ◽  
Carl J. Houtman ◽  
Alexander N. Kapich ◽  
Christopher G. Hunt ◽  
Daniel Cullen ◽  
...  

ABSTRACT Brown rot basidiomycetes initiate wood decay by producing extracellular reactive oxygen species that depolymerize the structural polysaccharides of lignocellulose. Secreted fungal hydroquinones are considered one contributor because they have been shown to reduce Fe3+, thus generating perhydroxyl radicals and Fe2+, which subsequently react further to produce biodegradative hydroxyl radicals. However, many brown rot fungi also secrete high levels of oxalate, which chelates Fe3+ tightly, making it unreactive with hydroquinones. For hydroquinone-driven hydroxyl radical production to contribute in this environment, an alternative mechanism to oxidize hydroquinones is required. We show here that aspen wood undergoing decay by the oxalate producer Postia placenta contained both 2,5-dimethoxyhydroquinone and laccase activity. Mass spectrometric analysis of proteins extracted from the wood identified a putative laccase (Joint Genome Institute P. placenta protein identification number 111314), and heterologous expression of the corresponding gene confirmed this assignment. Ultrafiltration experiments with liquid pressed from the biodegrading wood showed that a high-molecular-weight component was required for it to oxidize 2,5-dimethoxyhydroquinone rapidly and that this component was replaceable by P. placenta laccase. The purified laccase oxidized 2,5-dimethoxyhydroquinone with a second-order rate constant near 104 M−1 s−1, and measurements of the H2O2 produced indicated that approximately one perhydroxyl radical was generated per hydroquinone supplied. Using these values and a previously developed computer model, we estimate that the quantity of reactive oxygen species produced by P. placenta laccase in wood is large enough that it likely contributes to incipient decay.


2013 ◽  
Vol 778 ◽  
pp. 818-822
Author(s):  
Jiří Frankl

This paper presents results of experimental laboratory establishment of changes in physical properties (swelling, water absorption) of timber (spruce, pine, oak) caused by wood-destroying fungi (Serpula lacrymans, Stereum hirsutum). The experiment was carried out using standard test samples (20x20x30 mm) prepared from new timber and subsequently exposed to the wood-destroying fungi under optimal growth conditions for the period of 10 to 30 days. Changes in physical properties were observed in the damaged samples in compliance with CSN 490126 (equivalent to ISO 4859-1982, equivalent to ISO 4860-1982) and CSN 490104 Czech National Standards. The experiment proved changes in the observed properties depending on the wood and fungi species and the duration of the exposure.


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.


Author(s):  
I. J. Holb

The effect of acidity (pH) ranges on the mycelial growth and stroma formation of Monilia fructigena Pers: Fr. and of M. polystroma van Leeuwen was determined on agar plates and apple fruits. Four isolates of each of the brown rot fungi and two apple cultivars, `James Grieve' and 'Cox's Orange Pippin', were used for the study. For the agar plate study, a range of the initial pH was prepared from 2.5 to 6.5. The dishes were inoculated with a 4 mm plug of each isolate and incubated at 23 °C in darkness. The mycelial growth was measured after 1.5, 4, 7, 10 and 20 days of incubation. After a 30-day incubation, stroma formation was determined by image analysis and weighing of mature stroma. In the fruit experiment, both cultivars were inoculated with one isolate of M. fructigena and of M. polystroma. The pH changes were determined after 7, 14, 28 and 35 days of incubation in both healthy and inoculated fruits. The fastest mycelial growth was at pH 4.5 for M. polystroma and at pH 3.5 for M. fructigena. After a 30-day incubation, M. polystroma isolates produced twice or three times more stroma compared to M. fructigena isolates. For both brown rot fungi, the amount of mature stroma increased from pH 3.5 to 5.5, and then decreased at pH 6.5. Results of the.fruit experiment showed that healthy fruits were quite acidic (pH < 3.5), but pH rapidly increased in the inoculated fruits for both cultivars, reaching pH 4.6-5.4 depending on cultivar and fungus isolate. On both cultivars, the stroma developed at a significantly higher pH for M. polystroma than for M. fructigena. Biological and practical implications of the results are discussed.


Author(s):  
Inger Skrede ◽  
Claude Murat ◽  
Jaqueline Hess ◽  
sundy Maurice ◽  
Jørn Henrik Sønstebø ◽  
...  

Globalization and international trade have impacted organisms around the world leading to a considerable number of species establishing in new geographic areas. Many organisms have taken advantage of human-made environments, including buildings. One such species is the dry rot fungus Serpula lacrymans, which is the most aggressive wood-decay fungus in indoor environments in temperate regions. By using population genomic analyses of 36 full genome sequenced isolates, we revealed that isolates from Europe and Japan are highly divergent and that these populations split 3,000 - 19,000 generations ago, probably predating human influence. Approximately 250 generations ago, the European population went through a tight bottleneck, likely corresponding to the time it colonized the built environment. Moreover, evidence of admixture between European and Japanese populations was shown in an isolate from New Zealand. Genomic analyses revealed that low differentiation appeared in genes with functions related to of growth and intracellular transport, possibly important to its ability to effectively decay large substrates. These functions may have enabled both populations to independently establish in the human-made environment. Further, selective sweep analyses identified rapid changes in genes possibly related to decay of various substrates in Japan and in genes involved DNA replication and protein modification in Europe. These two fungal populations were preadapted to the built environment, but have more recently and independently adapted to their local environment.


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