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The 1999-2000 annual report for the IRG - Wood Preservation in Egypt
2000 - IRG/WP 00-40188
The wood destroying insects in Egypt are belonging to several families of Coleoptera, Lepidoptera and Isoptera. Imported woods are treated by The Agricultural Quarantine or the authorized companies. The materials used for protection as pre-treatment are the same of the treatment. They are Bromide methyl, copper or fluoride salts, organo-phosphorus compounds, pyrethroides, creosote or creosodial. Any preservative should be evaluated by the Ministry of Agriculture before recommendation. Of the preserved woods are Lumbers, sleepers and poles, woods used in constructions and furniture as well. The woods used in furniture, constructions or woodworks are mostly imported from Sweden, Russia, Finland or Korea. Several kinds of woods are imported as Picea sp., Pinus sp., Phagus sp. Local woods used are limited in kinds and amount, as Casuarina sp., Eucalyptus sp., Ficus sp., Acacia sp. Treated woods are potentially increasing in use. There are neither restriction for the use of treated woods, not any regulation concerning the desposal of these woods.
S I M Moein
The leachability and specificity of the biological protection of timber using Scytalidium sp. and Trichoderma spp
1986 - IRG/WP 1302
The results of field experiments, using biological control against internal decay of creosoted poles, are briefly reviewed and the evidence concerning the leachability of the antibiotics produced by these species is presented. A pure culture miniblock decay test on biological control treated pine sapwood is described and the results compared to previously published data. The protection against Lentinus lepideus (Fr. ex Fr.) Fr. conferred on wood blocks by Scytalidium sp. and Trichoderma sp. was found to be completely removed by 24 hours Soxhlet leaching. Weight losses caused by Coniophora puteana (Schum ex Fr.) Karst were not reduced by prior colonisation of blocks with the potential biological control fungi. The significance of this finding is discussed in the light of the high frequency of isolation from poles of wood rotting basidiomycetes other than Lentinus lepideus and the latest results of a six year old field experiment.
P I Morris, N A Summers, D J Dickinson
Marine performance of preservative treated Southern pine panels. Part 2: Exposure at Mourilyan Harbour, Queensland, Australia
2000 - IRG/WP 00-10337
Southern yellow pine panels treated with ACQ type B, ACQ type A, CCA type C, creosote, and copper naphthenate have been exposed at Mourilyan Harbour, north Queensland, Australia for almost 6 years. These panels have been inspected and rated for fouling and attack by Teredinid, Limnoria, Martesia, and Sphaeroma during this exposure. After 70 months exposure, overall performance of ACQ type B was equivalent to CCA type C at similar loadings, while ACQ type A did not perform as well. CCA and ACQ at 40 and 20 kg/m3 are performing similar to creosote at 430 and 200 kg/m3, respectively. The copper naphthenate treated panels did not perform as well as the ACQ panels at similar total copper loadings. Fouling of panels treated with ACQ was less than that found on CCA and creosote treated panels, but similar to that found on copper naphthenate treated panels exhibiting the same level of performance.
A R Zahora, A F Preston, K J Archer, S Kleinschmidt
The yeast Pichia sp. As a short-term biological control agent to fungal spoilage of sawn softwood timber
2000 - IRG/WP 00-10362
Previous work has found isolates of the yeast Pichia to be a successful biological control agent toward moulding of fruits. An isolate was tested for the ability to protect sapwood of Pinus sylvestris timber against visual degrade by surface growth of moulds and staining fungi. Successful protection of autoclaved wood sprayed with a mixture of common wood moulding fungi was achieved when the yeast was applied at a rate of 6 x 10 8 cells/cm2. Yeast cells were sprayed onto the wood blocks at the same time as the fungi and blocks were incubated under conditions favourable to fungal development for 15 and 25 days before assessment using a visual scale. Limitation of the disfigurement of green wood required a similar cell application rate. Protection of blocks sprayed with Ophiostomatoid staining fungi following sterilisation required a lower concentration of yeast cells (2 x 10 6 cells/cm2). Survival and reproduction of Pichia cells on sterilised wood blocks was also determined across a range of relative humidity and temperature conditions previously found to support development of wood moulding and staining fungi. Following 16 weeks incubation at temperatures of 8-25°C at relative humidity 93-100%, between 46 and 473% of the number of colony forming units applied to the wood were recovered. Maximum increase in viable yeast cell count on wood blocks occurred at 100% relative humidity and 15°C.
C Payne, H J Staines, A Bruce
Laboratory evaluation of chlorothalonil formulation for stain and mold control on rubberwood and maple
1998 - IRG/WP 98-30175
We evaluated the efficacy of several chlorothalonil and carbendazim fungicides (F1 and F2), etc. in the control of mold and stain fungi on rubberwood and maple. The results showed that these formulations effectively inhibited the selected fungal species such as Aspergillus niger, Penicillium sp., Trichoderma sp. (P71H), Aureobasidium pullulans, Ceratocystis minor (C-188), Ceratocystis pilifera (RWD 9472) in laboratory tests.
Mingliang Jiang, T L Highley, L Ferge, T L Woods
Laboratory tests on light organic solvent preservatives for use in Australia. - Part 6: Soft rot resistance of three fully formulated preservatives on different timber substrates
2000 - IRG/WP 00-30245
The above-ground soft rot resistance of substrates treated with three fully formulated light organic solvent preservatives (Cuprivac Green WR, Impresol WR 205 and Vacsol) was studied using a modified vermiculite burial method. The substrates were sapwood of Pinus elliottii and P. radiata and heartwood of Eucalyptus regnans, Pseudotsuga menziesii, Shorea sp. (a lower and a higher density source) and Thuja plicata. Following artificial weathering, replicate test blocks were exposed to either Chaetomium globosum or Lecythophora mutabilis. C. globosum caused 3% or more mass loss of the water and solvent (white spirit) impregnated controls of all three hardwoods and two of the four softwoods, whereas L. mutabilis caused similar attack in only E. regnans and P. radiata. The P. menziesii and T. plicata heartwoods were naturally durable to both soft rot fungi and, hence, no further conclusions can be drawn. None of the preservatives, at the highest retention tested, protected E. regnans from attack by C. globosum, whereas the highest retentions of both the Cuprivac Green WR and Impresol WR 205 protected all other timbers from this fungus. At the highest retention, the latter preservative was the only one to protect E. regnans from L. mutabilis.
G C Johnson, M A Tighe, J D Thornton
Natural resistance of Bamboo (Bambusa sp.) to marine wood-borers in Goa waters (India)
1993 - IRG/WP 93-10032
The paper deals with the natural durability of Bambusa sp. against the attack of marine wood-borers in Goa waters. Test specimens of this species were completely destroyed within a short period of nine months due to severe attack of borers indicating its very low natural resistance. Wood-borers involved were Martesia striata (Linnaeus), Nausitora hedleyi Schepman and Lyrodus pedicellatus (Quatrefages). The need for improving the durability of bamboo by suitable preservation techniques for its effective utilisation under marine conditions has been highlighted in the paper.
L N Santhakumaran, S G Sawant
Natural durability of 4 different Larix species tested in soil contact
2002 - IRG/WP 02-10434
Importers of Siberian Larch claimed to have a material which can replace pressure treated wood in soil contact. This gave reason to investigate the durability of 4 different Larix species (L. decidua, L. sibirica, L. decidua x sibirica, L. gmelini var ologenis) coming from 7 different origins in comparison with sapwood of Pinus sylvestris untreated as well as pressure impregnated with retentions of 2 and 9 kg CCA per m³. 10 mini stakes of each material in the size of 200 x 20 x 8 mm were installed in 1997 in the soil of the BFH test site (altitude = 24 m above see level, latitude = 53.5028 North, longitude = 10.1982 East). Within the first 2 years all except one untreated specimen of the Scots pine sapwood had failed. Within the first 3 years all except one of the Scots pine with a retention of 2 kg of CCA had failed. Within 5 years all specimen of Larix spp., independent from the species, had failed, whereas the pressure impregnated Scots pine with a retention of 9 kg CCA / m³ was either not or only slightly attacked. Mean life time and the average life time - which were about the same - served to classify the natural durability of the tested materials according to EN 350-1 (1994). All tested material was in the range of the value given in EN 350-2 (1994): "moderately to little durable" (European durability class 3-4). This was also valid for Siberian larch with narrow grow rings. From this results can be concluded that the performance of Larix heartwood in ground contact is far below that of wood properly treated with 9 kg CCA / m³. The field results are compared with earlier lab results using the same source of Larix material (IRG/WP 97-10228; IRG/WP 98-10287; IRG/WP 00-10350).
A O Rapp, H Viitanen, T Nilsson
A comparison of effectiveness of three waterborne preservatives against decay fungi in underground mines- An appraisal
2005 - IRG/WP 05-30366
To understand the effectiveness of waterborne preservatives and to explore the behaviour of roof supporting poles after pressure treatment, an experiment was conducted and thorough investigation was carried out during the last decade in the underground mines. Prior to commencement of the experiment, a survey was conducted at different depths in underground mines and collected decayed wood samples and got them identified. The waterborne preservatives used in underground mines were CCA, CCB and ACC. Two species of timbers namely Casuarina equisetifolia and Eucalyptus hybrid were treated by pressure process. Absorption of preservatives were calculated and penetrations were carried out on selected poles. Retention of salts were estimated. Preservative treated poles along with controls were installed at different depths consisted of varied environmental conditions of relative humidity, temperature and water seepage in underground mines. Absorption on the condition of test poles and effectiveness of preservatives were carried out after every six months for over 8 years. Observation revealed that untreated controls were destroyed by decay fungi within 3 to 5 years, whereas treated poles remained serviceable even after 8 years of exposure and estimated to last for over 12 years. Environmental factors like warm and humid air coupled with water seepage contributed for rapid decay of timbers in mines. The overall observation on the efficacy of preservatives indicated that in spite of a close competition among preservatives for superiority, CCA and CCB were found effective against decay fungi as compared to ACC.
Laboratory tests on the natural durability of timber methods and problems
1984 - IRG/WP 2217
In literature a large variety of test methods is mentioned to examine the natural resistance of timber against fungal attack. This concerns the kind of sampling as well as the test procedure, the test fungi, the duration of test, and the classification of the resistance according to the test results. These variations, however, are of great influence on the test result. Long term exposure will lead to a further differentiation of timber species to be generally known as "resistant".
Differential susceptibility of living and dead timber to colonisation by sapstain and mould fungi
1998 - IRG/WP 98-10288
Field studies have revealed that when timber is irradiated (i.e. killed) it is more susceptible to colonisation by mould fungi than sapstain fungi. By comparison, freshly sawn timber shows very little mould colonisation, tending to be colonised by sapstain fungi. It appears, therefore that the physiological state of the wood may influence the pattern of colonisation. A laboratory trial was undertaken to investigate in more detail the observations recorded in the field studies. A spore suspension of the mould Trichoderma was used to inoculate one set of living and one set of gamma irradiated (dead) wood blocks; similar sets of blocks were inoculated with a spore suspension of the sapstain fungus Ophiostoma piceae and a final treatment consisted of inoculating further sets of blocks with a mixed spore suspension of both fungi. Results clearly indicated that Trichoderma rapidly colonised and discoloured the irradiated blocks whereas there was very little defacement on the living blocks. The dead wood blocks inoculated with the mixed spore suspension were also rapidly colonised by the mould Trichoderma and 0. piceae was clearly out competed. However the living wood blocks were predominantly colonised by 0. piceae when they were inoculated either alone or in combination with Trichoderma. The factors controlling these patterns of colonisation are being investigated.
J R Williams, D J Dickinson, J F Webber
Study of the degradation caused by micro-organisms in Pinus sp. waterlogged wood
1989 - IRG/WP 1411
So far, the different Centers are trying the restoration and the conservation of wood structures, coming from subaquatic archeological deposits, with interest from the historic - artistic point of view. The main objective of this paper has been the determination of the decay level of Pinus sp. wood coming from a roman ship (approximately 2000 years old), where we have analyzed their physical properties, their chemical composition and the marine microorganisms (microfungi and bacteria) within.
M T De Troya, M C Escorial, J Garcia, A Cabanas
Intraspecific variability of durability of Wapa courbaril (Eperua grandiflora) against Antrodia sp. and Coriolus versicolor: effect of radial and height position in the stem
2004 - IRG/WP 04-10531
The variation of a lesser-used species, Eperua grandiflora attacked by brown and white rot has been examined. Trees of this specie showed differences in their behaviour against the type of rot used and also showed evidence of intra and inter tree variation. The “tree” effect is very significant concerning natural resistance. In the same way, there is variation of durability observed according to radial and vertical position in the stem. Although the vertical effect is less significant from practises point of view.
N Amusant, J Beauchêne, M Fournier
Soft-rot in Tabebuia sp. wood used in water cooling tower:
identification and degradation capacity of the fungi
1998 - IRG/WP 98-10253
Tabebuia sp. (ipe), a native Brazilian wood, is considered of high natural resistance to decaying fungi, and has been used in harsh environments, as cooling towers. Fifty-one fungi, belonging to mitosporic fungi group (Fungi Imperfecti), were isolated from deteriorated Tabebuia sp. wood samples, collected from the mist eliminator and packing of a cooling tower in operation for about 23 years. The degradation capacity of these fungi was evaluated by soft-rot tests using Eucalyptus grandis and Pinus elliottii wood. The microscopic examination of wood sections showed that Acremonium sp., A. kiliense, Phialophora sp. and Phialophora butyrii caused type 1 soft-rot attack in both mod species, while Fusarium oxysporum, Gliocladium spp., Moniliella-like, Penicillium sp., Pullularia pullulans, Trichoderma spp. and Verticillium sp. were not able to produce the same attack. These results and the analyses of weight loss suggested that Acremonium spp. and Phialophora spp. more important decaying organisms of Tabebuia sp. in the cooling tower.
S Brazolin, M Tomazello, I H Schoenlein-Crusius
Enzymatic study of Ceratocystis sp., blue-stain fungi on Pinus nigra
1999 - IRG/WP 99-10315
One of the main problems that the forest exploitation industry has with Pinus nigra wood is the blue-stain fungi, whose causing agent is unknown. Therefore, the objective of this work has been to study, through enzymatic tests of the isolated cultures, if these fungi infect Pinus nigra in any specific way. After the incubations, isolates of Ceratocystis were obtained. These were cultured in a saline medium with sawdust of Pinus nigra and Pinus sylvestris, which were used as reference species. At different incubation times, carboxymethylcellulase, xylanase, cellobiohydrolase, laccase and manganese peroxidase were determinated. The results obtained show that the cellulolytic enzymes and laccase have higher activity on Pinus nigra sawdust than on Scots pine, while the Mn peroxidase showed higher values on the sawdust of the latter. Likewise, the cultures were developed in the same saline base medium with different monosacarides (glucose, galactose, mannose, xylose and arabinose), and in determining the residual sugar content, a marked prefrence for the consumption of pentoses in respect to the glucose was observed. The enzymatic activity tests carried out by APY ZYM also showed qualitative and semiquantitative differences between the isolated fungi and other Ceratocystis species tested, so, in addition to the above results, this could indicate a certain specificity of these fungi for this wood species.
M T De Troya, F Rubio, D Muñoz-Mingarro, F Llinares, C Rodríguez-Borrajo, M Yuste, M J Pozuelo, J I Fernández-Golfín
Utilisation of carbohydrates by stain fungi in agar culture
1998 - IRG/WP 98-10248
Stain fungi are often defined by their ability to utilise the starch and free sugars found in ray parenchyma cells, and their inability to utilise other wood constituents. However, several species of stain fungi produce bore holes in wood cell walls. This suggests that enzymatic activity capable of degrading structural polysaccharides and/or lignin is associated with the growth of the appressorium and transpressorium structures developed by these stain fungi. This pilot study examined possible base media for growth of three common blue-stain fungi isolated from hardwood sawmills in Victoria, Australia. Alternaria alternata (Fr.) Keissler, Graphium/Ophiostoma sp., and Aureobasidium pullulans (de Bary) Arnaud were grown on agar supplemented with a variety of carbon sources, and mycelial growth rates were measured to determine which carbohydrates can be used by these fungi.
J Snow, P Vinden, S M Read
Degradation of resin constituents in various wood species by the white rot fungus Bjerkandera sp. strain BOS55
1999 - IRG/WP 99-10301
In previous studies, the white-rot fungus Bjerkandera sp. strain BOS55 was shown to cause extensive degradation of lipophilic extractives (resin) in Scots pine wood. Further research was carried out in order to investigate the ability of Bjerkandera sp. for reducing resinous constituents in various softwood (Douglas fir, larch and spruce) and hardwood species (birch, beech and poplar). The greatest resin reduction occurred in beech (79% in two weeks). High levels of resin elimination were also observed in softwood species like spruce (36%) or Scots pine (35%), as well as in hardwood species like poplar (32%) or birch (24%). In contrast, Bjerkandera sp. only caused a negligible loss of resin components in Douglas fir wood chips. HPLC analysis of acetone extracts from control and fungal-treated samples showed a rapid elimination of triglycerides, diglycerides, free fatty acids and sterols. Toxic constituents in softwood species like resin acids were partially removed in Scots pine, spruce and larch (29-34% in two weeks).
J Dorado, T A Van Beek, F W Claassen, R Sierra-Alvarez
Biological control in termite management – the potential of nematodes and fungal pathogens
2004 - IRG/WP 04-10521
A brief overview on the options for biological control of termites is presented. Many organisms have been identified as being able to kill termites, however, we do not know their real impact on field populations of termites. Most research has focused on some entomopathogenic nematodes and the fungi Beauveria bassiana and Metarhizium anisopliae. To date, only a limited number of field studies have been conducted using both groups of organisms as control agents for termites. Work with M. anisopliae, notably from Australia, is discussed in more detail in this paper. Strains selected for field trials have to: be virulent; be able to tolerate temperatures above 30ºC; pose no health threats to humans and higher animals; be easily mass produced; and have long-lived spores that are robust enough for easy formulation and storage. Spores from virulent isolates of M. anisopliae are repellent to termites and behavioural defence mechanisms by termites can limit the effectiveness of conidia applications. A number of options are available to formulate the spore product thus rendering it less repellent. Applications of conidia as inundative treatments to termite sites, or within an attractive bait matrix, are options for termite control with M. anisopliae. Microbial pathogens will solve certain termite problems but may not help with others. However, they have their place as one of the tools in integrated termite (pest) management.
Phenol oxidase activity and one-electron oxidation activity in wood degradation by soft-rot deuteromycetes
2007 - IRG/WP 07-10615
Wood degradation, one-electron oxidation activity as assayed by ethylene generation from 2-keto-4-thiomethylbutyric acid (KTBA), and phenol oxidase activity were measured in cultures of six deuteromyce fungi, with glucose or wood as the carbon source. The four fungi that degraded Japanese beech wood had higher one-electron oxidation activities in wood-containing cultures than in glucose-containing cultures. These four fungi also had measurable phenol oxidase activity in wood-containing cultures, but not in glucose-containing cultures. The two mould fungi that did not significantly degrade wood had no phenol oxidase activity in either wood- or glucose-containing cultures. The one-electron oxidation activity in intact cultures of the soft-rot deuteromycetes was roughly related with the rate of mass loss during wood degradation in those cultures. However, there was no clear relationship between phenol oxidase activity and either one-electron oxidation activity or the rate of wood mass loss, either over time, or in total. Most of the one-electron oxidation activity resulted from phenol oxidase and hydroxyl radical. Most of the phenol oxidase activity resulted from laccase. Furthermore, the mechanism of wood degradation by one of these deuteromycete fungi, Graphium sp., was investigated. Most of the phenol oxidase activity appeared to derive from laccase. Most of the ethylene generation from KTBA was attributed to hydroxyl radicals, produced by a low-molecular-mass substance in the extracellular media. This substance was composed of protein, carbohydrates, and Fe(II), and catalyzed redox reactions between O2 and unidentified electron donors, to produce hydroxyl radicals via H2O2. It is suggested that hydroxyl radicals may produce new phenolic substructures on the lignin polymer, making it susceptible to attack by laccase. Thus, one-electron oxidation acitivity and laccase activity are both important in wood degradation by Graphium sp.
H Tanaka, M Yamakawa, S Itakura, A Enoki
Influence of ring width and wood density on durability of oak heartwood
2008 - IRG/WP 08-10639
Oak (Quercus sp.) is considered as one of the most durable European wood species. The most important factor influencing oak durability was extractive content. In our work, we were interested in if oak-wood durability is affected by ring-width and related density. Therefore, oak heartwood specimens made of boards with different ring widths were exposed to five different fungal species Daedelea quercina, Antrodia vaillantii, Hypoxylon fragiforme, Stereum hirsutum and Trametes versicolor according to the EN 113 procedure. In parallel, extractives and nitrogen content were determined as well. From the gravimetrically determined mass losses, and microscopical analysis of decayed specimens, it can be resolved, that oak heartwood specimens with the narrowest growth rings and consequently lower density, were more susceptible to fungal decay than denser specimens made of wider growth rings. Durability of oak heartwood with rings of 0.77 mm and density around 550 kg/m3, is comparable to durability of common beech.
M Humar, P Oven, F Pohleven
Wood decay fungi from New Zealand leaky buildings – PCR identification (Part 2) and aerial spore trapping
2008 - IRG/WP 08-10649
Prior to this study, it was not know which species of decay fungi caused decay in New Zealand leaky buildings. Use of molecular biology methodology, polymerase chain reaction (PCR), and subsequent DNA sequencing, as well as classical mycological techniques based on morphology, has enabled identification of decay fungi and has provided insight into their relative importance based on isolation frequency. Fungi colonising Pinus radiata D. Don framing timber of leaky New Zealand buildings were isolated to produce pure cultures. Mycelia from these cultures on agar media were collected to extract DNA. To identify the fungi to the species level, PCR with primer pairs NSI1 + NLB4 and ITS1-F + ITS4 were performed followed by sequencing of the internal transcribed spacer (ITS) region. Identification was by BLAST (Basic Local Alignment Search Tool) search on sequences in GenBank. In total, 421 samples from leaky buildings were processed, mainly decayed timber, but also fibre cement boards and building paper. Sixty-eight fungal identifications were achieved of which 4 species are very common as follows: • Gloeophyllum sepiarium (Wulf.: Fr.) Karst. 13x • Oligoporus placenta (Fries 1865) Gilb. In Ryv.1985 11x • Antrodia sinuosa (Fr.) Karst. 8x • Gloeophyllum trabeum (Fr.) Murr 4x An aerial spore study of internal air, wall cavity air and exterior air of leaky buildings was carried out using a Merck MAS-100 instrument which collects spores directly onto various selective media plates. Also, decayed wood samples from the same leaky buildings enabled identification of G. sepiarium and A. sinuosa at the same test site. Viable fungal aerial spores were detected at every sampling location, with a highest mean of 3714 colony-forming units (CFU) per square meter found in water-damaged walls. The use of Carboxymethylcellulose medium further demonstrated the presence of cellulose degrading fungi within and around the location. Overall, the combination of these two approaches proved useful for detection of fungal species variation at a multi-unit building complex and it was possible to identify the brown rot decay fungal genus Antrodia with both methods.
D Stahlhut, R L Farrell, R Wakeling, M Hedley
Evaluación de oxinato cúprico como alternativa al tribromofenato de sodio, para uso como funguicida antimancha. Ensayo final y conclusiones
2008 - IRG/WP 08-30481
This study evaluated the efficacy of oxine-copper (Cas Nº 10380-28-6. Synonyms: copper oxyquinolate, cupric-8-hydroxyquinolate, copper-8-quinolinolate) for the control of stain fungi in lumber. Three field tests were established and sodium tribromophenate was used as a reference preservative. Boards of Pinus elliotis and P. taeda were treated by dipping for 15, 30 or 60 seconds in two different formulations both containing 5% of active ingredient. The first field test was set up in “El Dorado” (Province of Misiones, northeast Argentina). This is an important commercial forest area in which climate conditions are very favorable for stain fungi development. Both formulations provided protection but one was more effective. However, after dipping the test site experienced unusually heavy rainfall which could have influenced the results. Consequently, two additional field tests were undertaken based on the results of the first trial. The new trials were located in “Santa Rosa de Calamuchita” (Province of Cordoba) and in “Panambí” (Province of Misiones). Oxine-copper provided protection under the conditions of the three locations tested. Este documento muestra resultados de tres ensayos de campo realizados para evaluar la eficacia, como funguicida antimancha para maderas aserradas, del principio activo oxinato cúprico ( Cas Nº 10380-28-6 , acepciones: oxiquinolato de cobre, cobre 8 hidroxiquinolato, quinolinolato de cobre 8 ). Oxinato cúprico El estudio se realizó tomando tribromofenato de sodio como patrón y evaluando los resultados en condiciones identicas de ensayo . Tribromofenato de sodio El 1º test se realizó en la localidad de “Eldorado”, provincia de Misiones, en el extremo noreste de nuestro país. Esta zona es de extraordinaria importancia forestral en Argentina, y además presenta las condiciones climáticas más favorables para el desarollo de hongos de coloración. El 2º y el 3º test se realizaron basados en las conclusiones del 1º, en las localidades de “Santa Rosa de Calamuchita” (provincia de Cordoba) y en la localidad de “Panambí” (provincia de Misiones). El oxinato cúprico se utiliza en distintos tipos de formulaciones en Australia, Nueva Zelanda, USA, España, Brasil, Chile, etc, y teniendo en cuenta estos antecedentes se decidió evaluarlo como alternativa en nuestro país. El 1º ensayo mostró resultados alentadores para decidir su empleo, sin perjuicio de continuar las evaluaciones. Las pruebas concluyeron con el 2º y 3º ensayo, los cuales mostraron la efectividad del principio activo estudiado.
M Alba Valle
Optimization of oxalic acid production for bioleaching of metal components from CCA-treated wood by an unknown Polyporales sp. KUC8959
2010 - IRG/WP 10-50266
A brown-rot fungus, an unknown Polyporales sp. KUC8959, has recently been identified and proven as a prominent fungal species for bioremediation of CCA-treated wood wastes in our Lab. The fungus produced a larger amount of oxalic acid than other fungi tested, and removed 90 % or more of chromium, copper and arsenic from CCA-treated wood sawdust through bioleaching process. The bioleaching process was consisted of two steps comprising fermentation of the fungus for oxalic acid production and then extraction of metals by oxalic acid produced by the fungus. In order to maximize bioleaching efficiency, optimal fermentation conditions for oxalic acid production by the fungus is required. The objective of this study was to optimize oxalic acid production by unknown Polyporales sp. KUC8959. We used a 20-run central composite design (CCD) using response surface methodology (RSM) with three variables, that is, nutrient concentration, fungal biomass, and fermentation period. From the pre-cultured liquid fermentation broth, fungal hyphae were removed by filtering and then washed thoroughly with sterile deionized water. In accordance with the experimental design, fungal biomass (6.99, 18.32, 34.93, 51.55, or 62.88 mg) was inoculated in a flask containing 100 mL of malt extract solution (0.5, 1.11, 2, 2.89, or 3.5 %). Thereafter, the flask was agitated at 150 rpm on a rotary shaker at 27 °C for 48, 96.66, 168, 239.34, or 288 hours. From the fermentation broth, the amount of oxalic acid produced was determined by high performance liquid chromatography. The fitted RSM model investigated showed high regression coefficient between the variables and the response (R2=0.960) indicating that the model can be highly accurate in predicting the oxalic acid production at various conditions. The model suggested that optimum nutrient concentration, fungal biomass, and fermentation period were 2.40 %, 47.84 mg and 228.96 hours, respectively, to produce 4.11 g/L of oxalic acid. This fitted model will further be used for bioleaching of metals from CCA-treated wood.
Yong-Seok Choi, Min-Ji Kim, Jae-Jin Kim, Gyu-Hyeok Kim
Performance of untreated wood and wood impregnated with copper-ethanolamine based preservative solutions in Northern Adriatic Sea
2013 - IRG/WP 13-30623
Sea water applications of wood are among the most challenging ones. Impregnated wood is exposed to leaching and to variety of marine borers, Limnoria sp. and Teredo sp. being the most important. In the present research, durability of pine wood impregnated with copper-amine based preservative solution (Silvanolin) of different concentrations, exposed to the sea water, was investigated according to the EN 275 standard. Performance of Silvanolin treated wood was compared to performance of naturally durable wood (Quercus sp., Castanea sativa, Larix decidua). After 10 months, 18 months and 32 months of exposure, the samples were isolated and assessed. From the presented results it can be clearly seen, that durable wood species were completely degraded after 10 months of exposure. On the other hand, it is evident that Silvanolin prolongs the service life of exposed wood in the sea. The specimens impregnated with the lowest concentration of the preservative solution (cCu = 0.31 %) were only slightly decayed. At specimens, impregnated with higher concentrations of copper (cCu > 0.31 %) almost no defects were observed as a results of exposure to marine borers.
M Humar, M Petrič, J Adamek, B Lesar
NGS analysis of fungal OTUs in Aquilaria sp. from French Guyana, Cambodia, Laos and Thailand
2017 - IRG/WP 17-50328
Aquilaria is a tree species belonging to the Thymeleaceae family. When Aquilaria sp. is injured, it produce agarwood. Agarwood is characterized by a darker wood colour than the healthy one and by a strong perfume that is much esteemed by perfumers and some oriental religious communities. The production of agarwood is presumed to depend of environmental factors, among them fungi. The aim of this work is to obtain an overview of fungi present in Aquilaria sp. from different countries. Aquilaria sp. is endemic to South East Asia including notably Cambodia, Laos and Thailand, where it is cultivated to produce agarwood. In French Guiana, native south East Asian farmers would like to locally produce agarwood in their field. That’s why we wonder if fungal communities inducing agarwood are the same between these countries. NGS was used to characterize fungal communities associated with agarwood. 693,961 sequences that cover ITS2 estimated about 250 bp have been obtained. These sequences have been grouped into 535 OTUs, displaying 100% identity. 87 % were Ascomycetes and 10.5 % were Basidiomycetes. These results show differences in fungal communities between aboveground and belowground parts of the tree. Likewise differences between countries within fungal communities were also observed. Notwithstanding our results highlight common OTU between the different countries. Comparisons between aboveground parts and belowground parts and comparisons between different countries showed that several different fungal species may be responsible of the infection, other factors may disturb the community after infection and some samples may be not infected. From this study, some candidates potentially involved in agarwood production were selected. The role of these fungi in the induction of agarwood production will be further studied.
C Zaremski, C Malandain, O Sibourg, C Andary, G Michaloud, M Ducousso, N Amusant, A Zaremski