Potential valorization of wood extractives from waste products of steam distillation of Aniba rosaeodora: antitermitic activity

Aniba rosaeodora, is a slow growing evergreens of the Lauraceae family which are indigenous over a wide range of the Greater Amazon Region (the Guianas and Venezuela, Brazilian Amazon¿). The essential oil obtained from the wood has a characteristic aroma and is a long-established ingredient in the more expensive perfumes. The wood is also composed with alkaloid compounds like anibin. These compounds contribute to the protection of the wood against insects and fungi. This work is focused on the valorization of steam distillated sawdust; the sawdust was extracted with methanol in order to study the antitermitic activity of the extract. The methanolic extract shows an efficacy against termites at low concentrations according to the EN 117 standard. (Résumé d'auteur

Antifungal activity of wood extractives from waste products of steam distillation of Aniba rosaeodora

Aniba rosaeodora, is a slow growing evergreens of the Lauraceae family which are indigenous over a wide range of the Greater Amazon Region (the Guianas and Venezuela, Brazilian Amazon...). The essential oil obtained from the wood has a characteristic aroma and is a long-established ingredient in the more expensive perfumes. Around the olfactive characteristic of the essential oil is due to the presence of levogyre linalol. The steam distilled wood oil is obtained in a yield ranging around 1% and up to 90% of the oil consists of optically active linalol. This work is focused on the valorization of steam distillated sawdust, waste obtained from extraction of essential oil. After steam distillation, the sawdust was extracted by ethyl acetate and methanolic solvents and the antifungal activity was evaluated against basidomycetes fungi. The both extracts were active in vitro against white and brown rot fungi and allowed to propose these extractives as wood preservative agent. (Résumé d'auteur

Taxonomic Study of French Guiana Fungi to Identify and Isolate Pure Cultured Fungi for Oleoresin Production in Aquilaria: Use of Sequences from the Small Ribosomal DNA (R) Subunit (SSU) and the Two Primer Pairs SR6/SR10R and SR7/SR1R

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

Soil property effects on the natural durability, extractive content and colour of teak (Tectona grandis L.f) wood in Togo

Togolese teak is highly resistant to pathogen attack, but natural durability and wood colour vary according to plantation sites and geographical zones. Therefore, further information concerning the influence of environmental parameters and their effects on teak wood quality is necessary and it could be possible to improve these characteristics through tree breeding and silviculture programs in Togo. In order to examine the influence of soil properties on teak wood characteristics, 321 wood samples issued from 20 trees were exposed to two fungi: #Antrodia sp#., and #Coriolus versicolor#. Depending on type of soil in which they grew, trees had been randomly selected in two different sites in the same climatic area in Togo. The colour parameters of each sample were measured using the CIELAB system and total extractive content was determined using the Accelerated Solvent Extraction (ASE) procedure. Results showed a significantly lower total extractive content (11.1%) for trees that grew on hydromorphic tropical ferruginous (HTF) soil than trees from drained ferruginous soil (12.8%). Samples from HTF soil were lighter and the redness a* and yellow-blueness b* were significantly higher. Independently of soil quality, all the trees were highly durable regarding decay by #C. versicolor#. With #Antrodia sp#., 90 % of the trees from both sites were highly durable and only 10% were durable. However, samples from HTF soil were less durable with regard to the two fungi. (Résumé d'auteur