scholarly journals Strength properties and natural durability of Avocado (Persea americana Mill.) branch wood

2016 ◽  
Vol 17 (1) ◽  
pp. 37-47 ◽  
Author(s):  
F. J. Fuentes-Talavera ◽  
J. A. Silva-Guzmán ◽  
R. Rodríguez-Anda ◽  
M. G. Lomelí-Ramírez ◽  
R. Sanjuán-Dueñas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Persea Americana ◽  
White Rot ◽  
Natural Durability ◽  
Agar Block ◽  
Impact Bending ◽  
Property Profile ◽  
Branch Wood

This paper reports on mechanical properties and natural durability of avocado branch wood (Persea americana Mill.) with the objectives of providing a reliable property profile and to promote the rational use of this abundant yet largely neglected natural resource.  The mechanical properties (static bending, compression, shear, impact bending) and hardness were determined in accordance with European standards (CEN). Natural durability was assessed according to the European standard EN 350-1 (agar block test) using the white rot fungi Trametes versicolor and Phanerochaete chrysosporium, and the brown rot fungus Postia placenta. Avocado trees yield a low to medium density (0,44-0,54-0,64 g/cm3 at 12% mc) branch wood with below average strength under static bending, compression and tension parallel to the grain and average values for longitudinal shear, impact bending and hardness. The wood is rated non-resistant (class 5 according to EN 350-1) and thus is not suitable for exterior applications unless treated. Considering its property profile and the small dimensions available, avocado wood is recommended for general carpentry, furniture, interior paneling, glue-boards for closets and cabinets, and glue-lams for indoor framework.

Decay resistance of softwoods and hardwoods thermally modified by the Thermovouto type thermo-vacuum process to brown rot and white rot fungi

Holzforschung ◽  
2016 ◽  
Vol 70 (9) ◽  
pp. 877-884 ◽  
Author(s):  
Jie Gao ◽  
Jong Sik Kim ◽  
Nasko Terziev ◽  
Geoffrey Daniel
Keyword(s):  
White Rot Fungi ◽  
Brown Rot ◽  
Decay Resistance ◽  
Fungal Species ◽  
White Rot ◽  
Agar Block ◽  
Pycnoporus Sanguineus ◽  
Postia Placenta ◽  
Soil Block ◽  
Class 1

Abstract Softwoods (SW, spruce and fir) and hardwoods (HW, ash and beech) were thermally modified by the thermo-vacuum (Termovuoto) process for 3–4 h in the temperature range 160–220°C (TMW160–220°C) and their fungal durability were examined in soil-block tests with two brown rot (BR, Postia placenta, Gloeophyllum trabeum) and two white rot (WR, Pycnoporus sanguineus, Phlebia radiata) fungi. SW-TMW160–220°C were exposed to P. placenta and P. sanguineus and HW-TMW190–220°C to all fungal species. Considerable improvement (durability class 1–3) in decay resistance was only achieved for SW- and HW-TMW220°C. Thermal modification (TM) below 200°C influenced decay resistance negatively in case of some fungal species applied for both SW and HW. Judged by the durability class, decay resistance was higher in HW- than in SW-TMW at high TM temperature. Behavior of TM differed significantly between ash (ring-porous HW) and beech (diffuse-porous HW). A comparison between results of soil- and agar-block tests on Termovouoto wood demonstrated that the influence of testing method in terms of assignment to durability classes is not significant.

Mechanical properties and chemical composition of beech wood exposed for 30 and 120 days to white-rot fungi

Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 587-593 ◽  
Author(s):  
Ehsan Bari ◽  
Hamid Reza Taghiyari ◽  
Behbood Mohebby ◽  
Carol A. Clausen ◽  
Olaf Schmidt ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Beech Wood ◽  
White Rot Fungi ◽  
White Rot ◽  
Chemical Components ◽  
Fungal Decay ◽  
Oriental Beech ◽  
Impact Bending ◽  
Decay Tests

Abstract The effects of exposing specimens of Oriental beech [Fagus sylvatica subsp. orientalis (Lipsky) Greuter and Burdet] to the white-rot fungi Pleurotus ostreatus (Jacq.: Fr.) Kummer and Trametes versicolor (L.: Fr.) Pilát strain 325 have been studied concerning the mechanical properties and chemical composition in terms of carbohydrates, cellulose, and lignin. Biological decay tests were carried out in accordance with the EN 113 standard specifications for 30 and 120 days. P. ostreatus had nearly the same deteriorating effects on the mechanical properties and chemical composition as that caused by T. versicolor. High and significant correlations were found between some mechanical properties with chemical components; for instance, the correlation coefficient (R2) between impact bending and carbohydrate content was about 0.96. The changes of components influence the various mechanical properties to a different degree. Incipient fungal decay caused severe changes for impact bending and carbohydrate loss. Several other properties declined at 120-day exposure time, such as the hardness, compression strength parallel to grain, and cellulose and lignin losses.

scholarly journals DECAY RESISTANCE, DIMENSIONAL STABILITY AND MECHANICAL STRENGTH OF POPLAR WOOD MODIFIED WITH PLANT-DERIVED COMPOUNDS

Wood Research ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 556-568
Author(s):  
JIAPENG WANG ◽  
ZHENJU BI ◽  
ZHANGJING CHEN ◽  
LI YAN ◽  
YAFANG LEI
Keyword(s):  
Mechanical Properties ◽  
Citric Acid ◽  
Dimensional Stability ◽  
Color Change ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Decay Resistance ◽  
White Rot ◽  
Modulus Of Rupture ◽  
Weight Percentage

The cinnamaldehyde, salicylic acid, stearolic acid and citric acid were plant-derived organic compounds that can be activated to fungi, that could degrade the wood in long term. The compounds with concentrations of 3%, 5% and 7% assisted by different dispersants were impregnated into poplar (Populus nigra L.) specimens by the vacuum-pressure method. After that, weight percentage gain (WPG), decay resistance against white-rot fungi (Trametes versicolor) and brown-rot fungi (Gloeophyllum trabeum), color change, dimensional stability and mechanical properties including modulus of elasticity (MOE) and modulus of rupture (MOR) were measured. The results indicated that cinnamaldehyde impregnated poplar showed antifungi activity against both G. trabeumand T. versicolor, and citric acid impregnated poplar showed antifungi activity against G. trabeum. The color of poplar specimens before and after impregnated cinnamaldehyde and citric acid had a little change, dimensional stability had been improved and mechanical properties especially for MOR increased significantly.

Revalorizing Lignocellulose for the Production of Natural Pharmaceuticals and Other High Value Bioproducts

2019 ◽  
Vol 26 (14) ◽  
pp. 2475-2484 ◽  
Author(s):  
Congqiang Zhang ◽  
Heng-Phon Too
Keyword(s):  
Clostridium Thermocellum ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Cost Effective ◽  
White Rot ◽  
Chemical Pretreatment ◽  
Significant Challenge ◽  
Drug Molecules ◽  
Natural Medicine ◽  
Renewable Natural Resource

Lignocellulose is the most abundant renewable natural resource on earth and has been successfully used for the production of biofuels. A significant challenge is to develop cost-effective, environmentally friendly and efficient processes for the conversion of lignocellulose materials into suitable substrates for biotransformation. A number of approaches have been explored to convert lignocellulose into sugars, e.g. combining chemical pretreatment and enzymatic hydrolysis. In nature, there are organisms that can transform the complex lignocellulose efficiently, such as wood-degrading fungi (brown rot and white rot fungi), bacteria (e.g. Clostridium thermocellum), arthropods (e.g. termite) and certain animals (e.g. ruminant). Here, we highlight recent case studies of the natural degraders and the mechanisms involved, providing new utilities in biotechnology. The sugars produced from such biotransformations can be used in metabolic engineering and synthetic biology for the complete biosynthesis of natural medicine. The unique opportunities in using lignocellulose directly to produce natural drug molecules with either using mushroom and/or ‘industrial workhorse’ organisms (Escherichia coli and Saccharomyces cerevisiae) will be discussed.

In vitro decay studies of selective delignification and simultaneous decay by the white rot fungi Ganoderma lucidum and G. tsugae

1986 ◽  
Vol 64 (8) ◽  
pp. 1611-1619 ◽  
Author(s):  
James E. Adaskaveg ◽  
Robert L. Gilbertson
Keyword(s):  
Ganoderma Lucidum ◽  
White Rot Fungi ◽  
Wood Decay ◽  
White Rot ◽  
Vitis Vinifera L ◽  
Prosopis Velutina ◽  
Agar Block ◽  
Selective Delignification ◽  
Simultaneous Decay

The in vitro wood decay abilities of Ganoderma lucidum (W. Curt.: Fr.) Karst. and G. tsugae Murr. were studied using the following woods in agar block decay chambers: Vitis vinifera L., Quercus hypoleucoides A. Camus, Prosopis velutina Woot., Abies concolor (Gord. & Glend.) Lindl. ex. Hildebr., and Pseudotsuga menziesii (Mirb.) Franco. Grape wood lost the most weight while mesquite the least. Ganoderma lucidum isolates generally caused greater weight loss of all woods than did G. tsugae isolates. The range of the percent weight losses varied with the wood. Both Ganoderma species caused simultaneous decay in all woods. However, chemical analyses of the decayed blocks indicated that selective delignification by both species also occurred in grape and white fir blocks. Chemical analysis of the decayed oak blocks indicated the percentages of lignin and holocellulose were not statistically different from the controls. However, there was a trend towards delignification. The analyses of the Douglas-fir blocks indicated only simultaneous decay. Scanning electron microscopy demonstrated selective delignification and simultaneous decay of all woods tested. However, the extent of the delignification differed among the wood species. Delignification appeared mainly in areas of tracheids or fiber tracheids, while the rays were simultaneously decayed.

scholarly journals Evaluation of Compressive Strength of Decayed Wood in Magnolia obovata

2010 ◽  
Vol 36 (2) ◽  
pp. 81-85
Author(s):  
Kahoru Matsumoto ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
Naoto Habu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Early Stage ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Soft Rot ◽  
White Rot ◽  
Chemical Components ◽  
Cellulose Content ◽  
Magnolia Obovata ◽  
Weight Loss Ratio

To obtain the basic information needed to estimate the degree of decay from compressive strength measured using a Fractometer (CS), relationships between CS and the contents of chemical components were analyzed for Magnolia wood decayed by three types fungi (brown rot, white rot, and soft rot fungi) at various decay levels. Weight loss ratio was significantly, negatively correlated with CS in woods decayed by brown rot and white rot fungi. In addition, a relatively high correlation coefficient was recognized between CS and holocellulose or α-cellulose content, except for wood decayed by soft rot fungus. The results obtained showed that Fractometer can detect the decrease of CS at relatively early stage of decay.

Condensed conifer tannins as antifungal agents in liquid culture

Holzforschung ◽  
2013 ◽  
Vol 67 (7) ◽  
pp. 825-832 ◽  
Author(s):  
Anna-Kaisa Anttila ◽  
Anna Maria Pirttilä ◽  
Hely Häggman ◽  
Anni Harju ◽  
Martti Venäläinen ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Fungal Growth ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Wood Preservative ◽  
Soft Rot ◽  
White Rot ◽  
Wood Preservatives ◽  
Active Components ◽  
Brown Rot Fungi

Abstract In the last decades, many wood preservatives have been prohibited for their ecotoxicity. The present article is focusing on the conifer-derived condensed tannins as environment-friendly options for the substitution of artificial wood preservatives. Eight different tannin fractions were extracted from spruce cones, spruce barks, and pine cones. The parameters of tannin extraction, such as the methods of purification and concentration of active components in the extracts, have been investigated. The cone and bark extracts were tested for the growth inhibition of eight brown-rot fungi, three white-rot fungi, and four soft-rot fungi in liquid cultures. The cone tannins provided a more efficient fungal growth inhibition than bark tannins. Purification increased the antifungal properties of the extracts. The growth of brown-rot fungi was inhibited by the tannins already at low concentrations. However, the extracts were not effective against the white-rot or soft-rot fungi. More investigation is needed concerning the tannin source and the purification procedure of the extracts before tannins can be considered as an ecologically benign wood preservative.

Wood Degradation by Brown-Rot and White-Rot Fungi

2004 ◽  
pp. 355-368 ◽  
Author(s):  
T. Mester ◽  
E. Varela ◽  
M. Tien
Keyword(s):  
White Rot Fungi ◽  
Brown Rot ◽  
White Rot ◽  
Wood Degradation

scholarly journals The Impact of Paraffin-Thermal Modification of Beech Wood on Its Biological, Physical and Mechanical Properties

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1102 ◽  
Author(s):  
Ladislav Reinprecht ◽  
Miroslav Repák
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Beech Wood ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
White Rot Fungus ◽  
Poria Placenta ◽  
The Impact

The European beech (Fagus sylvatica L.) wood was thermally modified in the presence of paraffin at the temperatures of 190 or 210 °C for 1, 2, 3 or 4 h. A significant increase in its resistance to the brown-rot fungus Poria placenta (by 71.4%–98.4%) and the white-rot fungus Trametes versicolor (by 50.1%–99.5%) was observed as a result of all modification modes. However, an increase in the resistance of beech wood surfaces to the mold Aspergillus niger was achieved only under more severe modification regimes taking 4 h at 190 or 210 °C. Water resistance of paraffin-thermally modified beech wood improved—soaking reduced by 30.2%–35.8% and volume swelling by 26.8%–62.9% after 336 h of exposure in water. On the contrary, its mechanical properties worsened—impact bending strength decreased by 17.8%–48.3% and Brinell hardness by 2.4%–63.9%.

Formation of heartwood, chemical composition of extractives and natural durability of plantation-grown teak wood from Mexico

Holzforschung ◽  
2019 ◽  
Vol 73 (6) ◽  
pp. 547-557 ◽  
Author(s):  
Raúl Rodríguez Anda ◽  
Gerald Koch ◽  
Hans-Georg Richter ◽  
Francisco Javier Fuentes Talavera ◽  
José Antonio Silva Guzmán ◽  
...  
Keyword(s):  
Large Scale ◽  
Tree Height ◽  
Brown Rot ◽  
White Rot ◽  
Clear Correlation ◽  
Natural Durability ◽  
Qualitative Properties ◽  
Age Classes ◽  
High Mechanical Strength ◽  
Teak Wood

AbstractCurrently, there is an increasing interest in Mexico to grow teak in large-scale plantations. Teak is recognized for its natural durability combined with high mechanical strength. The present study aims at determining the quantitative and qualitative properties of teak wood for several age classes and provenances, originating mainly from three localities of south eastern Mexico, while the focus was on the extractives and the natural durability of teak samples. The percentage of heartwood (hW) formed by the plantation trees was within the range reported elsewhere for the corresponding age classes, while the hW% was in relation with the tree height and age. Further trends observed were: lower topo-chemical absorbance that was measured by ultraviolet microspectrophotometry (UMSP) of the inner hW compared to the outer hW; no clear correlation between the age and origin and the extractives’ composition accumulated in the hW; abundant presence of tectoquinone irrespective of the age and provenance; and finally, high resistance against white rot (WR) and brown rot (BR) fungi regardless of the age or provenance.

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