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Role of microbiota in wood degradation by Reticulitermes grassei and Bursaphelenchus xylophilus
2022 - IRG/WP 22-20684
Xylophagous organisms can cause damage both in forests and in felled wood. Bursaphelenchus xylophilus, which causes "Sudden Pine Wilting" in coniferous forest masses, and is currently considered a quarantine organism in the European Union. On the other hand, structural and carpentry wood is affected by subterranean termites (Reticulitermes spp.), that cause serious damage, both in buildings and furniture. Solutions for the control of both organisms have been evaluated, and mainly based on chemical or physical treatments. Lately more eco-sustainable biocontrol and/or bioprotection techniques are being investigated. Among these techniques, the modification of the associated microbiota is being studied, in nematode or entomopathogenic microorganisms, with metabolites that are capable of controlling both organisms. As these products are of biological origin they may minimize the environmental impact. The application of these latest techniques requires a deep understanding of the associated microbiota. Therefore, the objective of this work has been to identify the microbiota present in Bursaphelenchus xylophilus and Reticulitermes grassei, as well as their main enzymatic activities and how they may play important roles in the degradation of wood. The results have shown cellulase, chitinase and protease activities, enzymes that could serve as indicative parameters in the control of both organisms. This study opens future treatment techniques against both pests, within a sustainable bioeconomy.
L Robertson, S Rames, M Uriel, J M González, F Llinares, S M Santos, M T Troya


rDNA-ITS sequence of Serpula lacrymans and other important indoor rot fungi and taxon-specific priming PCR for their detection
1999 - IRG/WP 99-10298
Taxon-specific priming polymerase chain reaction (TSPP) is a powerful molecular tool for fungal diagnosis. For its application to indoor rot fungi, the internal transcribed spacer (ITS) of the ribosomal DNA (rDNA) of the main fungal species causing wood rot in European buildings was amplified with the polymerase chain reaction (PCR). The ITS region was sequenced. The complete sequences are presented. From base sequence divergency among the fungi, species-specific oligonucleotide primers were designed for TSPP. These marker molecules were suitable for the differential diagnosis of the dry rot fungus, Serpula lacrymans, the wild merulius, S. himantioides, the oak polypore, Donkioporia expansa, the brown cellar fungus, Coniophora puteana, the broad-spored white polypore, Antrodia vaillantii, the sap polypore, Tyromyces placenta, and the yellow-red gill polypore, Gloeophyllum sepiarium. Each specific marker identified isolates of its respective target species. Cross reaction with 'foreign' fungi was the exception. Species identification from unknown field samples from rot damage in buildings is also possible, because DNA from contaminating organisms does not response to the specific primers. Our variant of the technique is fast, because no preceding fungal pure cultures, no special DNA extraction/purification, and no restriction by endonucleases are necessary.
O Schmidt, U Moreth


16S rRNA Analysis of the Bacteria Associated with Biocide Degradation
2004 - IRG/WP 04-10543
The bacterially mediated degradation of the new anti-fungal biocide, bethoxazin, was studied in vitro, by means of 16S rRNA PCR-amplification and cloning techniques. Woodblocks impregnated with a subtoxic concentration of bethoxazin were incubated in compost, and the micro-organisms associated with the wood after 6 and 12 weeks was studied. It was found that after 6 weeks the wood contained a large number of proteobacteria, including Pseudomonas fluorescens, Bordetella petrii, Asticcacaulis biprosthecium and Alcaligenes spp. These organisms appear to be the dominant organisms involved in bethoxazin detoxification. After 12 weeks, the population of bacteria was found to have altered considerably, with the dominant bacteria being identified as Afipia, Rhizobium and Verrucomicrobium. This population is thought to have developed after the biocide had been detoxified and represents a succession in the wood, outcompeting the previous detoxifying population.
D F Wallace, D J Dickinson


Detection of the dry rot fungus Serpula lacrymans by amplified ribosomal DNA restriction analysis
1998 - IRG/WP 98-10245
Isolates of the dry rot fungus Serpula lacrymans and the wild merulius S. himantioides were investigated by amplified ribosomal DNA restriction analyses (ARDRA) of the internal transcribed spacers (ITS). The technique uses the polymerase chain reaction (PCR) to amplify the variable region of the ITS between the conserved 18S and 28S genes of the nuclear ribosomal DNA (rDNA). The ITS region of all isolates of Serpula lacrymans and S. himantioides was successfully amplified. The length of the amplified product was about 630 bp. Subsequent double digest of the ITS with the restriction endonucleases Haelli and Taql separated the closely related fungi by species-specific fragments. Thus, ARDRA-ITS proved to be suited for the detection of the dry rot fungus.
O Schmidt, U Moreth


Amine Oxides for Use in Wood Protection: II: Water Repellent Agents for Wood
2007 - IRG/WP 07-30426
Wood treated with cetyl and stearyl amine oxides was evaluated to determine its long term water repellency. Comparative water uptake data, generated during two years of outdoor exposure, illustrated that Lonza’s products, Barlox® 18S (N-octadecyl-N, N-dimethylamine oxide) and Barlox® 16S (N-hexadecyl-N, N-dimethylamine oxide), were effective water repellent agents, imparting lasting water resistance in treated wood. A conventional wax based water repellent system showed superior initial results for water resistance; however, the water repellent ability of the wax based system started to degrade after four months of weathering and was significantly deteriorated after two years of outside exposure.
Xiao Jiang, L Walker


Isolation and evaluation of Lactobacillus brevis from chilli waste for potential use as a wood preservative
2011 - IRG/WP 11-10749
Lactic acid bacteria were isolated from chilli waste and evaluated for their ability to arrest wood rotting basidiomycetes. In previous work a quick screening method using 96 well plates and measuring absorbance to determine fungal growth was developed specifically to investigate the efficacy of isolated bacteria against wood decay fungi. Using this method, one bacterium (isolate C11) was identified from three bacterial isolates as having significant antifungal properties against Oligoporus placenta. This isolate was identified as Lactobacillus brevis by 16S rRNA gene sequencing and BLAST analysis of the NCBI database. To determine antifungal activity in wood, Pinus radiata blocks were impregnated with L. brevis strain C11 cell free supernatant (CFS) and exposed to brown rot fungi O. placenta, Antrodia xantha, and Coniophora puteana. The CFS treated timber demonstrated resistance to degradation from all fungi especially when L. brevis was incubated for one week before filtering the culture to retrieve the supernatant. To determine the nature of the bacterial metabolites affecting fungal growth, the affect of pH, temperature and proteinaceous enzymes on the CFS was assessed using the 96 well quick screening method. The antifungal metabolites were heat stable and not affected by proteinase K, but were affected by neutralisation with NaOH suggesting the metabolites were of an acidic nature.
D O’Callahan, T Singh, I R McDonald


Molecular characterization and biodiversity of wood-decaying fungi in French Guiana
2014 - IRG/WP 14-10825
Fungi from tropical regions are currently under-represented in the classification system. Indeed, difficult access to tropical forests and irregular occurrence carpophores make it complicated to study fungus species in such environments, unlike in European zones where fungal diversity and taxonomy are better known. The purpose of this work was to enhance classification by integrating new data that would bring out the importance of certain traits of these fungi, and provide a clearer understanding of how the biodiversity of fungi from the forest ecosystems of French Guiana is organized, particularly those causing wood decay through white rot, brown rot or soft rot. In our study, we chose to work in the zone comprising the internal transcribed spacers ITS1 and ITS2, which are relatively variable, and the 5.8 S small ribosomal subunit, which is not highly variable. The primers ITS 1(5’-TCCGTAGGTGAACCTGCGC-3’) and ITS 4 (5’-TCCTCCGCTTATTGATATGC-3’), specific to fungi, were chosen for this taxonomic analysis of the studied species. This study was carried out on 101 fungus fruiting bodies at the Paracou forest site in French Guiana. Of those 101 fungi, 72 were identified by BLASTn. Four species were Ascomycetes of the genus Muscodor and Xylaria. The other 68 species, all in the class of the Basidiomycetes, were divided into the following orders: 31 Agaricales, 1 Atheliales, 2 Boletales, 1 Gomphales, 12 Polyporales, 1 Trechisporales and 1 Tremellales. There was also an indeterminate taxon very similar to the lichens. Within the order Polyporales, the main genera were found, such as Antrodiella, Coriolopsis, Fomitopsis, Ganoderma, Lentinus, Pycnoporus, Steccherinum, Trametes, Fomitoporia. All these fungi have the particularity of causing wood decay.
A Zaremski, L Gastonguay, C Zaremski, J Beauchene


Biodiversity of wood-decaying fungi in French Guiana sequences of the small subunit (SSU) of ribosomal (r) DNA and the two primer pairs SR6/SR10R and SR7/SR1R
2019 - IRG/WP 19-10936
Fungi from tropical regions are currently under-represented in the classification system. Indeed, difficult access to tropical forests makes it complicated to study fungus species in such environments, unlike in European zones where fungal diversity and taxonomy are much better known. The purposes of this work were: a) to enhance classification by integrating new data that would bring out the importance of certain traits of these fungi, and provide a clearer understanding of how the biodiversity of fungi from the forest ecosystems of French Guiana is organized, particularly those causing wood decay through white rot, brown rot or soft rot; b) to establish a collection of fungal isolates from fruiting bodies collected in French Guiana. This taxonomic study based on sequences of the small subunit (SSU) of ribosomal (r) DNA using the two primer pairs, SR6/SR10R and SR7/SR1R, was carried out on 39 fungus fruiting bodies from Cacao and Régina, in French Guiana. Our protocol enabled extraction, with good repeatability, of fungal DNA from a few mg of pure mycelium. With most of the strains studied we were able to obtain PCR products ranging in size from 376 to 625 base pairs. This study enabled to specify the taxa involved wood decay: 39 species were identified by BlastN. Most of them, in the class of the Basidiomycetes, were the main genera were found, such as Antrodia, Coriolopsis, Fomitopsis, Ganoderma, Poria, Lentinus, Pycnoporus, Auricularia, Gloeophyllum, Trametes, Fomitopsis, Rigidoporus. In addition to the above objectives, the production of pure mycelium from fruiting bodies identified in this study will be used to produce inoculum to test the ability of these fungal species in stimulating oleoresin production in Aquilaria trees from plantation established in French Guyana.
C Zaremski, A Ducousso-Detrez, N Amusant, A Zaremski