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

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.


1985 ◽  
Vol 63 (2) ◽  
pp. 337-339 ◽  
Author(s):  
Elmer L. Schmidt

Influences of eight saturated aliphatic acids (C5–C10, C12, and C16) on basidiospores of four isolates of wood-decay fungi (Poria tenuis and Trametes hispida, white rot fungi, and two isolates of the brown rot fungus Gloeophyllum trabeum) were observed in vitro. Spore responses after 24 h on malt extract agar containing 10, 102 or 103 ppm of each acid included normal germination, delay of germ tube emergence, vacuolation and degeneration of spore cytoplasm, and prevention of germ tube development without spore destruction. Acids of chain length C5–C10 prevented spore germination and killed spores of all fungi at concentrations of 20–50 ppm in media, whereas other acids tested were less active. Spore germination assay of decay fungi may prove useful as a screening tool to compare potency of wood preservatives.



IAWA Journal ◽  
2004 ◽  
Vol 25 (4) ◽  
pp. 425-433 ◽  
Author(s):  
María Luján Luna ◽  
Mónica Adriana Murace ◽  
Gabriel Darío Keil ◽  
Marcelo Eduardo Otaño

Populus deltoides clones are widely planted in Argentina, in a region called “Paraná River Delta”. In this site, Pycnoporus sanguineus and Ganoderma lucidum (Aphyllophorales) cause white-rot decay in both living and felled poplar trees. The purpose of this work was to estimate, through laboratory decay tests, the ability of both fungi to degrade poplar wood and to describe the patterns of decay using light and scanning electron microscopy. Two exposure times were analyzed: 75 and 150 days. The percent weight loss produced by both fungal strains was similar for both exposure periods (c. 50–60% of wood mass) but microscopic observations showed there were different patterns of decay. Samples inoculated with P. sanguineus showed a selective delignification, whereas those inoculated with G. lucidum exhibited a combination of simultaneous decay and selective delignification. Separation among cells was the main diagnostic feature for selective decay. By contrast, the presence of erosion troughs, cell wall thinning, bore holes, rounded pit erosion and erosion channels were diagnostic for the simultaneous type of decay.



IAWA Journal ◽  
2012 ◽  
Vol 33 (1) ◽  
pp. 91-104 ◽  
Author(s):  
María Luján Luna ◽  
Mónica A. Murace ◽  
Gerardo L. Robledo ◽  
Mario C. N. Saparrat

Schinopsis haenkeana is a native tree to the Chaco Serrano Forests in Argentina. The white-rot fungus Phellinus chaquensis degrades its wood, causing a whiterot type of decay. The objective of this study was to investigate the structural alterations caused by P. chaquensis in S. hankeana decayed naturally and in vitro. Sound living branches with decay and basidiocarps of P. chaquensis were sampled from the field and in vitro decay tests were performed according to the ASTM D-2017-81 standard method. Naturally decayed branches exhibited an innermost discolored zone with white-rot decay and an outer yellowish-white portion of sound sapwood. Using LM and SEM, degraded tissue displayed diagnostic characters of selective delignification and simultaneous decay. Findings indicate that P. chaquensis causes a mottled pattern of decay (selective delignification plus simultaneous decay) in S. haenkeana wood. Other features such as accumulation of extractives, profuse deposition of crystals and tyloses, typical ofSchinopsis spp. heartwood, were additionally observed. In laboratory degraded material, signs of selective delignification and incipient stages of simultaneous decay were noticeable only microscopically. Chemical analysis revealed an oxidative alteration of aromatic moieties in naturally decayed samples which might be related to the accumulation of phenols as a response to fungal attack when compared to sound samples. Naturally degraded sapwood exhibits anatomical and chemical modifications that indicate the development of discolored wood derived from the host-pathogen interaction.



IAWA Journal ◽  
1998 ◽  
Vol 19 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Laura Leviu ◽  
María Agueda Castro

Different stages of decay caused in vitro by Trametes trogii in Salix sp. and Populus sp. wood are described. Anatomical features are reported in three stages of this process. Decay progressed in a different pattern in both species studied. In Populus sp. T. trogii caused a combination of selective delignification and simultaneous decay within the same substrate. In advanced stages wood blocks exhibited large empty holes and a spongy structure. In Salix sp. a simultaneous white-rot decay took place. Only vessels remained and the residual white-rotted wood developed a stringy appearance.



2014 ◽  
Vol 8 (28) ◽  
pp. 2724-2732 ◽  
Author(s):  
Braga Pereira Bento Cludia ◽  
Soares da Silva Juliana ◽  
Teixeira Rodrigues Marcelo ◽  
Catarina Megumi Kasuya Maria ◽  
Cuquetto Mantovani Hilrio


2007 ◽  
Vol 2007 ◽  
pp. 197-197
Author(s):  
Hassan Fazaeli ◽  
Seyed Ahmad Mirhadi

Biological de-lignification of straw by white-rot fungi seems a promising way of improving its nutritive value. The bio-conversion of lignocellulosic materials is circumscribed to the group of white-rot fungi, of which some species of Pleurotus are capable of producing upgraded spent-straws as ruminant feed (Fazaeli et al., 2004). Treating of cereal straw with white-rot fungi as animal feed was studied by several workers (Gupta et al., 1993; Zadrazil, 1997). However, most of the trials were conducted at in vitro stage and used cell wall degradation and in vitro digestibility as an index to evaluate the biological treatments. This experiment was conducted to study the effect of fungal treatment on the voluntary intake, in vivo digestibility and nutritive value index of wheat straw obtained from short-term and long-term solid state fermentation (SSF).



2005 ◽  
Vol 2005 ◽  
pp. 137-137
Author(s):  
E. M. Hodgson ◽  
M. D. Hale ◽  
H. M. Omed

Straw constitutes a vast, valuable, and under utilised agricultural by-product, which has a great potential for utilisation as an animal feedstuff. However, due to the way in which it is constructed, the digestible sugars, cellulose and hemicelluloses, are tightly chemically bound by heavily lignified cell walls which provide the wheat plant stem with its strength and structure, but in doing so greatly inhibit the digestibility and nutritive value of the material to ruminant animals. Therefore, the utilisation of this resource as an animal feed can only be realised effectively, if the nutritional and digestibility values of the material can be improved by the innovation and successful application of an effective treatment method, be that physical, chemical or biological. Previously devised methods of upgrading the digestibility and nutritive value of forages, with the possible exception of urea treatment, have proven either insufficient, environmentally unsound, or economically infeasible to those concerned, particularly those in developing world. Therefore, there is a distinct need to develop techniques which can avoid these pitfalls and still yield the desired results in the context of animal nutrition. Previous research has indicated that members of the genus Pleurotus white rot fungi, have great potential for application in the biological upgrading of wheat straw. Therefore, the objective of this work was to investigate biological techniques, using 3 strains of Pleurotus fungi which may have the potential to be utilised in the biological upgrading of wheat straw.





Mycologia ◽  
1988 ◽  
Vol 80 (1) ◽  
pp. 124-126 ◽  
Author(s):  
Kevin T. Smith ◽  
Walter C. Shortle


1999 ◽  
Vol 65 (9) ◽  
pp. 3805-3809 ◽  
Author(s):  
Michael A. Pickard ◽  
Rosa Roman ◽  
Raunel Tinoco ◽  
Rafael Vazquez-Duhalt

ABSTRACT We studied the metabolism of polycyclic aromatic hydrocarbons (PAHs) by using white rot fungi previously identified as organisms that metabolize polychlorinated biphenyls. Bran flakes medium, which has been shown to support production of high levels of laccase and manganese peroxidase, was used as the growth medium. Ten fungi grown for 5 days in this medium in the presence of anthracene, pyrene, or phenanthrene, each at a concentration of 5 μg/ml could metabolize these PAHs. We studied the oxidation of 10 PAHs by using laccase purified from Coriolopsis gallica. The reaction mixtures contained 20 μM PAH, 15% acetonitrile in 60 mM phosphate buffer (pH 6), 1 mM 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS), and 5 U of laccase. Laccase exhibited 91% of its maximum activity in the absence of acetonitrile. The following seven PAHs were oxidized by laccase: benzo[a]pyrene, 9-methylanthracene, 2-methylanthracene, anthracene, biphenylene, acenaphthene, and phenanthrene. There was no clear relationship between the ionization potential of the substrate and the first-order rate constant (k) for substrate loss in vitro in the presence of ABTS. The effects of mediating substrates were examined further by using anthracene as the substrate. Hydroxybenzotriazole (HBT) (1 mM) supported approximately one-half the anthracene oxidation rate (k = 2.4 h−1) that ABTS (1 mM) supported (k = 5.2 h−1), but 1 mM HBT plus 1 mM ABTS increased the oxidation rate ninefold compared with the oxidation rate in the presence of ABTS, to 45 h−1. Laccase purified from Pleurotus ostreatus had an activity similar to that ofC. gallica laccase with HBT alone, with ABTS alone, and with 1 mM HBT plus 1 mM ABTS. Mass spectra of products obtained from oxidation of anthracene and acenaphthene revealed that the dione derivatives of these compounds were present.



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