IRG Documents Database and Compendium


Search and Download IRG Documents:



Between and , sort by


Displaying your search results

Your search resulted in 14 documents.


Diversity of hindgut symbiotic flagellate protist communities of the European subterranean termite in Portugal
2016 - IRG/WP 16-10875
The flagellate protist communities are an important part of the termite, as they lead the lignocellulose digestion. Termites (Reticulitermes grassei) were sampled from forest and urban environments in mainland Portugal where they are native and in Faial Island, Azores (invasive populations). Termites’ gut contents was analysed morphologically and the diversity of the flagellate protist community evaluated based on morphotypes. From the two Azorean invasive populations we were able to identify 12 different morphotypes whereas some of the populations in the mainland had as few as 6. Indeed, on the fourteen native populations the number of flagellate protists morphotypes ranged between 6 and 12. Shannon Wiener diversity index was used to calculate a variation partitioning between geographical and local variables. Our results suggest the existence of a core group of flagellate protists, probably performing key steps in the lignocellulose digestion. However, these communities may be more diversified and factors linked with the geographic location are likely a key influence of the flagellate protist communities analysed. In the invasive urban termite populations the high flagellate protist communities’ diversity, as well as the similarity between the two populations captured, may indicate a switch of R. grassei foraging and social habits in the invasive termite populations. Local conditions also influenced the flagellate protist communities, although not so markedly as geographic location. In this study, native termite colonies from urban environments showed the less diverse flagellate protist communities.
S Duarte, T Nobre, M Duarte, P A V Borges, L Nunes


Effects of geographical and dietary variation on the symbiotic flagellate protists communities of the subterranean termite Reticulitermes grassei Clément
2015 - IRG/WP 15-10847
Despite their importance on diverse ecosystems, termites may also be considered severe pests of wood in service, and also as agricultural and forestry pests. Subterranean termites’ ability to digest lignocellulose relies not only on their digestive tract physiology, but also on the symbiotic relationships established with flagellate protists and bacteria. In this tripartite lignocellulolytic system, the termite contribute with endogenous cellulases and mechanical processing, flagellate protists phagocyte the wood particles and digest them, and prokaryotes have, among others, an important role in maintaining the physical-chemical equilibrium inside the termite hindgut. The flagellate protist community living inside the termites is rather diverse, as there is a strong division of labour among them to accomplish the intricate process of lignocellulose digestion. The objectives of this work were to: 1) investigate the changes in flagellate protists communities of the termite Reticulitermes grassei in different locations; 2) test the possible effect of different laboratorial diets on diversity and abundance of the flagellate protists. R. grassei termites were captured in four different locations (Évora, Faial Island, Leiria and Sesimbra), in Portugal, and their symbiotic flagellate protist community diversity and abundance was evaluated. Termites belonging to the same colony were submitted to six different diets (natural diet, pine wood, European beech, thermally modified beech, cellulose and starvation) and after the trials their flagellate protist community was also evaluated. The differences between termite colonies from different locations may not be denied, although not considered to be significant. Similar flagellate protists communities were found on non-treated sound woods, while cellulose fed and starving termites had significantly different communities. The flagellate protists community of untreated beech and thermally modified beech fed termites were considered to be significantly different, with three morphotypes missing in the treated wood fed termites. Although the effects of geographical location were not considered significant, the laboratory diets caused major adaptations of the flagellate protists communities. The termite symbiotic flagellate protists community is a dynamic assemblage able to adapt to different conditions and diets.
S Duarte, M Duarte, P A V Borges, L Nunes


European standardization for wood preservation
1988 - IRG/WP 2321
G Castan


Reticulitermes (Ins., Isopt.) in Central and Western Europe
1969 - IRG/WP I 5A
Reticulitermes flavipes (Kollar) has established itself in Hamburg and Hallein coming from the east of North America. In France, on the northern boundary of termit occurrence, Reticulitermes santonensis are distinguished from Reticulitermes lucifugus by special activity and resistance. According to comparative investigations with colonies of several Reticulitermes species of different origins regarding the influence of temperature and soil moisture on the feeding activity and the viability of termite groups, Reticulitermes flavipes from Hamburg and one originating from Wisconsin (USA) show racial differences from the Hallein species originating from South Carolina. The first shows a daily rhythm of activity and are strong gallery builders, while the two latter lack these properties. Certain morphological differences may be correlative to the two bio-ecological races of Reticulitermes flavipes. Reticulitermes santonensis shows biologically and ecologically far greater similarity with Reticulitermes flavipes from Hamburg and Wisconsin than with Reticulitermes lucifugus. The samples from La Rochelle have symbiotic flagellate species which were otherwise only found either with Reticulitermes lucifugus or with the American Reticulitermes species. Morphologically the species occupies an intermediate position. Reticulitermes santonensis is likely to be a hybrid of Reticulitermes flavipes and Reticulitermes lucifugus, with the properties of a vigorous hybrid. So far it has been impossible to explain why up to now only Reticulitermes flavipes was able to establish itself sporadically in Central and West Europe.
G Becker


Reticulitermes (Ins., Isopt.) in Mittel- und West-Europa
1969 - IRG/WP I 4
In Hamburg und Hallein hat sich Reticulitermes flavipes (Kollar) aus dem Osten von Nordamerika eingebürgert. An der Nordgrenze des Termitenvorkommens im Westen Frankreichs zeichnet sich Reticulitermes santonensis Fetaud gegenüber Reticulitermes lucifugus durch besondere Aktivität und Widerstandsfähigkeit aus. Nach vergleichenden Untersuchungen an Kolonien verschiedener Reticulitermes-Arten mehrerer Herkünfte über den Einfluß von Temperatur und Bodenfeuchtigkeit auf Fraßtätigkeit und Lebensfähigkeit von Termitengruppen weisen die Reticulitermes flavipes-Tiere von Hamburg und einer Herkunft aus Wisconsin (USA) gegenüber den Tieren von Hallein und einer Herkunft aus South-Carolina Rassenunterschiede auf. Die ersteren zeigen einen Tagesrhythmus der Aktivität und eine starke Galleriebautätigkeit, die den beiden letzten fehlen. Gewisse morphologische Unterschiede lassen sich den beiden ökologisch-biologischen Rassen von Reticulitermes flavipes zuordnen. Reticulitermes santonensis ähnelt biologisch und ökologisch Reticulitermes flavipes von Hamburg und Wisconsin weit mehr als Reticulitermes lucifugus. Die Tiere von La Rochelle besitzen symbiotische Flagellaten-Arten, die sonst nur entweder bei Reticulitermes lucifugus oder bei amerikanischen -Arten vorkommen. Morphologisch nimmt die Art eine Zwischenstellung ein. Reticulitermes santonensis dürfte eine Kreuzung aus Reticulitermes flavipes und Reticulitermes lucifugus mit Eigenschaften eines luxurierenden Bastards sein. Bisher läßt sich nicht erklären, warum sich bislang nur Reticulitermes flavipes vereinzelt in Mittel- und Westeuropa einbürgern konnte.
G Becker


Effects of two wood preservatives and one water repellant on the settlement of fouling communities in a tropical marine environment
2002 - IRG/WP 02-30293
Observations made on recruitment of fouling organisms on treated panels exposed at an Indian harbour, Krishnapatnam on the east coast (Lat: 13028’ to 13059’ N; Long: 80010’ to 80016’ E) during November, 1997 to October, 1999 are reported and compared with fouling communities on control panels. Wooden panels of Erythrina variegata, Paraserianthus falcataria, Tetrameles nudiflora and Trema orientalis treated with 2 chemical preservatives i.e. CCA (Copper-Chrome-Arsenic) and CCB (Copper-Chrome-Borate) at four retention levels for each preservative (8, 16,24 and 32 Kg/m3) and one water repellant i.e. Chromic acid (8 % solution) was used in this studies. It was observed that the preservative (CCA,CCB) treated panels had greater initial settlement of barnacles, oysters, bryozoans and algae compared to untreated control panels. Serpulid settlement was heavier on untreated panels. Barnacles exhibited greater affinity for settling on CCA treated panels compared with CCB and Chromic acid. However, their settlement was lesser on panels with higher loadings (32 Kg/m3) in all treatments. Fouling communities settling on CCA treated panels showed retarded growth compared to CCB treatment but higher than controls. Oyster settlement was found to be more on CCB treated panels. The biomass and growth rates were high on CCB treated panels compared to CCA treated panels. On chromic acid treated panels, bryozoans and algal settlement was heavy but barnacles and oysters settlement was negligible. The biomass recorded also was lower than those of CCA, CCB and control panels. Fouling organisms also had lesser growth rates. Copper , chromium and arsenic levels were estimated in soft tissues of Balanus amphitrite and Crassostrea madrasensis that settled on treated panels. The values indicated that copper accumulated more in tissues followed by arsenic and chromium. Metal levels were found to be higher in C. madrasensis than B. amphitrite.
B Tarakanadha, K S Rao


Effects of chlorothalonil (CTN) and butylated hydroxytoluene (BHT) on microbial communities involved in the deterioration of wood using T-RFLP I: Accelerated laboratory decay study
2006 - IRG/WP 06-20332
The effects of Chlorothalonil (CTN) and Butylated Hydroxy Toluene (BHT) on microbial species diversity in wood and the surrounding soil are being assessed by Terminal Restriction Fragment Length Polymorphism (T-RFLP). CTN was selected as a trial organic wood preservative, and BHT is being evaluated for its synergistic effects with CTN. Results from an accelerated decay test will be presented. The accelerated decay test evaluates the performance of wood preservatives in conditions optimized to promote accelerated microbial degradation. This study is evaluating six retentions in two different soil mixtures (with and without compost), resulting in a total of twelve treatments. Each month, one box (containing three sticks) per treatment was removed to provide thirty-six samples per sampling period. Biomechanical stress testing is being utilized to determine modulus of elasticity (MOE) as a measure of microbial degradation. TRFLP data is being analyzed to determine significant differences in patterns of microbial colonization over time due to wood preservative treatment in southern yellow pine (SYP) both in and out of soil contact. Soil samples have also been collected to observe changes in soil microbial community due to contact with preservative treated wood. Wood preservative retention is being analyzed using HPLC. Initial results show decreases in fungal and bacterial phylotype diversity for both soil contact and non-soil contact portions of preservative treated SYP wood samples compared to untreated controls. Characterization of these pattern shifts will provide a better understanding of the biology and ecology of wood decay microorganisms, the effects of biocides on the microbial community in treated wood and in the soil, and the effects on microbes on biocide breakdown and wood failure.
G T Kirker, M L Prewitt, S V Diehl


Effects of chlorothalonil (CTN) and butylated hydroxytoluene (BHT) on microbial communities involved in the deterioration of wood using T-RFLP II: Results from field studies
2007 - IRG/WP 07-30429
The effects of Chlorothalonil (CTN) and Butylated Hydroxytoluene (BHT) on microbial species diversity in wood and the surrounding soil are being assessed by Terminal Restriction Fragment Length Polymorphism (T-RFLP). CTN was selected as a trial organic wood preservative, and the non-biocidal BHT was evaluated for its synergistic effects with CTN. ACQ-C was a positive control and untreated SYP stakes were negative controls. Tests were installed at two separate field sites in MS that represent two different AWPA hazard zones. Samples were taken every 3 months over a 15 month period and visually evaluated for termite attack and decay. Samples were processed and whole genomic DNA was extracted for molecular analyses. Upon initial amplification of DNA using both specific and general primers, the presence or absence of target fungi was confirmed using gel electrophoresis. We are currently using T-RFLP to analyze the patterns of microbial colonization over time and in response to external stimuli (i.e., wood preservative treatment) to identify potential shifts in microbial community. Preliminary results indicate that the presence of non-basidiomycete fungi (i.e. molds, stains, and soft rots) are uniformly distributed throughout the samples regardless of treatment, while basidiomycetes are less common and severe decreases in overall basidiomycete populations occurred during periods of drought at both test sites.
G T Kirker, M L Prewitt, S V Diehl


Biodegration of treated wood waste by native fungal communities of tropical soil in French Guiana
2012 - IRG/WP 12-50285
Woods have been protected with fungicides for a long time, and the effects of these fungicides on soil after being leached into the ground have turned out to be a true environmental issue. It is in this perspective that we are proposing to study fungal communities of these contaminated woods in a purpose of bioremediation. Most of precedent studies have focused on ability of some Basidiomycetes and white rot fungi to degrade these biocide products. Treated and reference (non-treated) woods samples have been incubated in containers of forest soil in Guyana. The first two samplings of these woods and soils have been realized five months apart. A crop and molecular study allowed us to isolate and identify forty strains of Ascomycetes able to develop on wood and resist xenobiotics. Until now, no Ascomycete was known to resist xenobiotics. Furthermore, a study of fungal communities of the woods and soil were done by D-HPLC and SSCP, and then analyzed by ACP. According to these analyses, biocides are leached in the soil and have an impact on these fungal communities, which are different depending on time of sampling and the way wood is processed.
A Zaremski, L Gastonguay, C Zaremski, F Chaffannel, J Beauchêne, G LeFloch


Tar-oil uptake vs time in immersion treatment of short pine posts: A simple technique applicable to rural communities of Papua New Guinea
2012 - IRG/WP 12-40608
Pinus caribaea and Araucaria cunninghamii logs ca. 100 mm in diameter were shortened to lengths 25-30 cm, conditioned to at/below fibre saturation point (FSP) for immersion/dip treatment using a hot- and- cold bath open- tank process. Before oven-drying and subsequent treatment, individual test specimens were numbered, their green weights and volumes, and dry weights recorded for basic density, void volume, preservative uptake and retention determination. The poles were bundled and immersed (dipped) in a drum containing light tar-oil creosote. The tar-oil creosote with pine specimens was heated to boiling for 30 minutes and flames were extinguished with water to allow cooling. The cooling conditions, (dip time period for treatment) varied from 1, 5, 15 and 24 hours. Theoretically, a vacuum was created in wood during heating and when cooled, tar-oil was drawn into the wood’s anatomical structures. The experiment results indicated that tar-oil uptake and retention increased with dip time until available void volume was filled and no further uptake occurred. In this case, the preservative uptake and retention were proportional with square-root of dip time. The technique was simple with basic materials required for hot and cold bath treatment. This treatment technique is more appropriate for application at rural community level for treatment of utility posts/poles.
B K Gusamo, R Tulo


Communities of mold fungi on flooded building materials
2013 - IRG/WP 13-10799
A small building built to residential code was flooded using farmland pond water to a depth of two feet at Tuskegee University. The building was drained and left enclosed for an additional three weeks. A total of 168 material samples were removed either immediately after opening (wet) or seven months after flooding (dry). Wall materials sampled included fiberglass batt insulation, gypsum wallboard, wood stud, plywood panels, vinyl siding, and house wrap and were analyzed by cloning and sequencing to identify the mold species present both above and below the water line. The vinyl siding and house wrap had the lowest mold growth while the batt insulation had very high quantities of mold, followed by the paper siding of the gypsum. The common types of molds present included Aspergillus, Chaetomium, Fusarium, Trichoderma, and Stachybotrys. The different molds were analyzed for presence on the different types and components of wall materials in areas exposed above and below the water line. In addition, real-time PCR quantitated selected mold species on different building materials. The mold species found in the highest concentration were Aspergillus fumigatus, Paecilomyces variotii, Chaetomium globosum, and Stachybotrys chartarum. The batt insulation supported the highest concentration of mold after flooding, followed by the wood stud, plywood sheathing, and gypsum wallboard. The highest level of mold on the dry materials was Aspergillus fumigatus on the dry wood stud and Stachybotrys chartarum on the dry gypsum. The focus of the research was to show that flood waters can penetrate into wall cavities of a home and the different wall materials become a substrate for different molds to develop, which potentially cause problems for some susceptible individuals.
F Skrobot III, H Aglan, S V Diehl


High-throughput sequencing highlighted contrasted pioneer fungal communities associated to coniferous and deciduous wood preservation assays
2013 - IRG/WP 13-10800
Studying the fungal communities in the wood, in particular during the first events of the colonization, and the factors that underlie the dynamics of fungal species assemblages remain a challenge in ecology, because of the absence of fructification during the pioneer steps of wood degradation. The use of Next-generation DNA sequencing methods, which produce massive volumes of data, provided new perspectives in fungal molecular ecology. In this paper we used high throughput sequencing to identify factors influencing fungal colonisation during the early stages of wood decay. For this purpose wood pickets, from different wood species, were buried in an experimental site, located on the island of Oléron, and removed after six and nine months of incubation. Then, total DNA was extracted and a library of the fungal internal transcribed spacer (ITS-1) region was prepared for 454 pyrosequencing. Our results revealed a strong host effect on the fungal communities associated to different wood species together with a spatial effect on fungal diversity. The source of inoculum was also investigated with the same approach from soil samples, and results demonstrated that the major source of fungal inoculum was not located, or very weakly represented, in the close environment of our pickets. Finally, the application of high throughput sequencing approaches was investigated to improve standards in order to be more representative of natural conditions.
Y Mathieu, A Dassé, I Le Bayon, M Kutnik, L Harvengt, E Gelhaye, M Buée


Communities of mold fungi in moisture damaged building materials
2014 - IRG/WP 14-20542
The critical conditions needed for the development of mould and decay fungi have been modelled for different building materials. However, current knowledge of indoor microbes growing on building materials relies on culture-based methods and more advanced molecular biological techniques should be employed to study the complex microbial communities in building materials. In this paper molecular biological techniques were optimized and used to study microbial diversity in building materials exposed to different moisture conditions. Different naturally contaminated and inoculated building materials were exposed to different humidity conditions (relative humidity 90% and 98%) in laboratory-scale experiment. The DNA extraction method was optimized to different building materials and microbial communities were studied by fungal ITS region targeted PCR-DGGE and sequencing. Fungal communities differed between building materials and humidity conditions. In RH 90% the majority of the sequences obtained belonged to genus Aspergillus. As expected, in RH 98% the fungal community was more diverse containing e.g. genera Penicillium, Aspergillus and Oidiodendron. The fungal diversity was highest in wood-based building materials.
E Sohlberg, H Viitanen


Response of the symbiotic flagellate protists community of subterranean termites to sublethal amounts of biocides
2018 - IRG/WP 18-10911
Subterranean termites are quite efficient at extracting nutrients from lignocellulose. Their ability relies not only on the digestive tract physiology but also on symbiotic relationships established with flagellate protists and bacteria. This work aimed to screen the response of the flagellate protists community of the subterranean termite Reticulitermes grassei Clément to the ingestion of different biocides. The substances chosen were applied at sublethal doses and included antibiotics (amoxicillin), an antiprotozoal (metronidazole), a termite intestine pH alteration agent and respiration inhibitor (boric acid), an essential oil (cloves) and its main constituent (eugenol), together with the solvent (water) and a positive control of pine wood. Termites were captured in three different zones of the same pine forest, sufficiently distant to be considered as different colonies; three replicate samples from each colony were selected for testing. Immediately after termite capture the initial flagellate protists community was evaluated for all samples (initial controls). Groups of termite workers were then fed on diet disks impregnated with the substances and, after the trials the diversity and abundance of the flagellate protist community was evaluated. Twelve morphotypes were present in the controls. The naturally less abundant morphotypes were positively associated with the termites screened before the trials and the ones fed on water treated diet disks or original wood. Metronidazole showed to affect negatively most morphotypes, however, two morphotypes’ abundance increased; these two morphotypes abundances decreased when termites fed on amoxicillin treated diet disks. For eugenol and boric acid significant negative impact was found for one morphotype with parallel increase in abundance of two others. Overall, the results suggest a possible maintenance of hindgut equilibrium or minimum functioning relying both on: changes on abundances of two or three morphotypes; and presence and abundance of the less common morphotypes. Three morphotypes exhibit differentiated response to changes in hindgut conditions, triggered by the addition of substances to the termite diet. This dynamic nutritional symbiosis equilibrium seems to provide a wide range of defences of the termite to exposure to substances potentially harmful and general dietary changes.
S Duarte, T Nobre, P Borges, L Nunes