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An attempt to evaluate wood resistance against fungal decay in non-sterile conditions by measuring the variation of resistance to bending test
1988 - IRG/WP 2308
The main object of this work was to determine the variation of strength on large test specimens of wood (800 x 45 x 45 mm³) when exposed to accelerated fungal attacks close to natural conditions, out of test vessels. The modulus of elasticity (MOE) and the modulus of rupture (MOR) have been assessed. Thereby, the natural resistance of the wood species to fungal decay, the efficiency of preservative as well as the treatment applied are discussed. The wood tested is a guianese secondary species (Couma guianensis). The fungi tested are two guianese strains of brown and white rot. The exposure time is 12 weeks. No mould contamination has been recorded by use of a selective fungicide. The results obtained show that it is possible to infest in nonsterile conditions large wood specimens. Furthermore, modulus of rupture appears to be the most reliable criterion. The investigation, that requires limited equipment and staff could be performed in any tropical research station as it has been done at CTFT, French Guiana center.
L N Trong

Efficiency of the Amazon Forest Oils as Preservatives to the Attack of cellulolytic fungi in Pine Wood
2012 - IRG/WP 12-30599
The bobbins of wood are used for storage and field installation of cables from the electricity and telecommunications sectors. There are legal requirements governing the Brazilian ways of treating the wood used in these sectors, aimed at preventing pollution and protecting nature. When exposed to severe environmental conditions in Brazil these products are degraded and occurs many operational problems. The timber is subjected to biodegradation by microorganisms, and in storage conditions, is more susceptible to attack by wood decay fungi. Continuous improvement of the quality of these products brings the need to search for new wood preservatives that meet the operational standards with lower environmental impacts. This paper presents results of study on application of three plant products of the Amazon forest: Linum usitatissimum (linseed oil - linhaça), Carapa guianensis (andiroba oil), copaifera officinalis (copaíba oil) and mineral oil as alternatives preservatives products for reforestation wood pinus caribeae; results are also presented obtained from mixtures of these oils in the proportions 1:1 (linseed oil, andiroba oil), 1:1 (linseed oil, copaiba oil), 1:1 (linseed oil, mineral oil) and 1:1:1:1 (linseed oil, andiroba oil, copaiba oil and mineral oil). Fungi were obtained on the degraded cable bobbin and, after growing the fungi in culture, they were inoculated in the samples to accelerate biodegradation. The samples were treated with oils, and subsequently tested in the field of natural aging (until 150 days) and by accelerated aging in the laboratory with Weather-O-Meter (until 1080 hours). Will be discussed the results of the degree of surface degradation, loss of mass, elemental analysis obtained for chemical characterization by energy dispersive x-ray detector (EDX). Samples without any treatment were used to compare the protective potential of the alternative oils.
S Silveira, I M S Mendes, R S Paiva, J E Volponi, R C G Comar, R S Cruz

Wood Natural durability study source of biomolecules: case of Dicorynia guianensis Amsh. heartwood
2016 - IRG/WP 16-10871
The chemical investigations of Dicorynia Guianensis heartwood led to the isolation of four new indole alkaloids for the first time in this plant Compound (1) identified as spiroindolone 2’,3’,4’,9’ -tetrahydrospiro [indoline-3,1’pyrido[ 3,4-b]-indol ]- 2- one, and compound (3) described as nitrone 1-methyl-4,9 -dihydro-3H-pyrido [3, 4-b] indole 2 – oxide and were isolated for the first time as natural products ABTS antioxydant activity guided their isolation and showed the potential of these compounds in industrial sectors
J-B Say Anouhe, A A Adima, F B Niamké, D Stien, B Kassi Amian, D Virieux, J-L Pirate,S Kati-Coulibaly, N Amusant

Interactions between fungal glutathione transferases and wood extractives
2017 - IRG/WP 17-10894
The interactions between extractives from several tree species of French Guyana and glutathione transferases (GST) from the white-rot Trametes versicolor have been studied. These interactions have been monitored using a thermal shift assay. It appears from these experiments that TvGSTO2S interacts strongly with acetonic extract of Bagassa guianensis and in particular with oxyresveratrol. In agreement with previous results, the obtained data suggest that the GST network could give insights on the adaptation of wood decaying fungi to their chemical environment.
T Perrot, F Saiag, N Amusant, S Dumarçay, P Gérardin, M Morel-Rouhier, R SormaniI, E Gelhaye

Comparison of 1H qNMR and NIR spectroscopic methods to predict heartwood decay resistance in Dicorynia guianensis Amsh
2017 - IRG/WP 17-20601
Dicorynia guianensis is by far the most exploited wood in French Guiana, as it is an abundant tree species associated with good technological properties. However, the decay resistance of D. guianensis wood against lignivorous fungi pathogens is sometimes variable. Therefore, the development of tools to predict the decay resistance of D. guianensis heartwood is relevant in wood science and agroforestry for ensuring a rational use of the resource. Two methods in analytical chemistry are reported herein using near infrared spectroscopy (NIRS) and quantitative nuclear magnetic resonance (qRMN) spectroscopy. Correlations of decay resistance assays with either alkaloid (tryptamine) quantification by qRMN or NIRS data, demonstrate that both predictive methods are prominsing and suitable to predict the decay resistance of D. guianensis heartwood.
C Flora, G Frédéric, M-F Thevenon, Y Estevez, C Duplais, N Amusant

Field tests of different tropical wood species in sea water
2022 - IRG/WP 22-30773
A number of tropical timbers have been tested according to EN 275 at Kristineberg Marine Research Station in Sweden since 1999. Most of these tests have started during the last 5-8 years. Wood species included have been Lophira alata (Azobé/Ekki), Minquartia guianensis (Manwood/Acaria), Chlorocardium rodiei (Greenheart), Cyclodiscus gabonensis (Okan/Denya), Shorea spp. (Bankirai), Dicorynia guianensis (Basralocus/Angélique), Tectona grandis (Teak) and Handroanthus spp. (Ipé). Only one of the wood species included have shown to be highly resistant to marine borer attack, Manwood/Acaria, which is also the wood specie that performed best in a marine test in Portugal (Williams et al. 2007). The test group of Manwood/Acaria is still rated “sound” after 22 years in our test. The performance of the other species is surprisingly poor with e.g., average life (time to failure due to shipworm attack) of only 3.8 years for both Greenheart and Okan/Denya. This seems to be in line with speculations about increased borer activity on the Swedish West coast causing increased shipworm attack on harbour constructions of tropical wood, mainly Azobé. In our test Azobé got an overall rating of “Failure” after 8 years in test.
M Westin, P Larsson Brelid