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Physical properties of ß-1,4-Xylanase produced by Postia (=Poria) placenta: Implications for the control of brown rot
1987 - IRG/WP 1318
The degradation of hemicelluloses is an early event in wood decay by brown-rot fungi. An understanding of the physical properties of hemicellulases may suggest target mechanisms for the development of new control agents. Endo-b-1,4-xylanase was partially purified by column chromatography from wood decayed by Postia (= Poria) placenta. The enzyme was extremely resistant to denaturing conditions; no...
J A Micales, F Green III, C A Clausen, T L Highley


The preliminary characterization of ß-1,4-xylanase of the brown-rot fungus Gloeophyllum trabeum
1990 - IRG/WP 1447
The extracellular ß-1,4-xylanase of the brown-rot fungus, Gloeophyllum trabeum, was isolated from crude extract by chromatofocusing method (PBE 94 column chromatography). The isoelectric point was estimated to 4.2-4.8 by cromatofocusing and 4.5 by isoelectric focusing (IEF). The molecular weight of the enzyme was estimated to 37,000 dalton by SDS-PAGE. The optimal temperature for the crude extrac...
A-C Ritschkoff, M Rättö, L Viikari


Preliminary studies on cellulase production by selected Basidiomycetes and the effect of copper-chrome-arsenate on these enzymes
1980 - IRG/WP 1122
The growth of wood-destroying fungi on ligno-cellulosic materials depends on the production of many enzymes, of which probably the most important is the multi component cellulase system. Within this system, at least three different kinds of enzym are believed to be involved in crystalline cellulose decomposition. These are endo-1,4-glucanase, exo-1,4-ß glucanase and ß-glucosidase. Most of the re...
O Collett


The effect of tunicamycin on production and secretion of extracellular carbohydrate-degrading enzymes by Postia placenta
1988 - IRG/WP 1342
The extracellular carbohydrate-degrading enzymes of wood-decay fungi are usually heavily glycosylated and therefore stable under most denaturing conditions. It is unlikely that wood decay can be prevented by simply inactivating these enzymes. Tunicamycin, an antibiotic produced by Streptomyces lysosuperificus, prevents the glycosylation of glycoproteins and can interfere with the secretion of thes...
J A Micales, T L Highley


Preliminary studies of the decay mechanism of some brown-rot fungi
1989 - IRG/WP 1402
The importance of the enzymatic degradation of hemicellulose and cellulose by brown-rot fungi is still under discussion. Endo-ß-1,4-xylanase and endoglucanase activities of Coniophora puteana and Poria placenta cultures were measured by the increase in reducing groups. Enzymes were produced in liquid and solid sawdust based culture media. Enzyme activities were measured in two, four and eight wee...
A-C Ritschkoff, H Viitanen


Immunolocalization of xylanase produced by Clostridium xylanolyticum Rogers and Baecker during anaerobic decay of Pinus patula
1991 - IRG/WP 1505
The xylanolytic fraction from a 72h culture of Clostridium xylanolyticum ROGERS and BAECKER was separated using non-denaturing PAGE and then used to raise polyvalent antisera in rabbits. Antibodies were purified using an affinity gel column and coniugated with colloidal gold. Pinus patula was exposed to axenic cultures of Clostridium xylanolyticum for 3 weeks, fixed, embedded and converted to ultr...
A A W Baecker, G M Rogers


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 sali...
M T De Troya, F Rubio, D Muñoz-Mingarro, F Llinares, C Rodríguez-Borrajo, M Yuste, M J Pozuelo, J I Fernández-Golfín


Immuno-scanning electron microscopic localization of extracellular polysaccharidases within the fibrillar sheath of the brown rot fungus Postia placenta
1991 - IRG/WP 1497
Extracellular polysaccharidases of the brown-rot fungus Postia placenta were localized using colloidal gold labeled monoclonal antibodies to the B-1,4-xylanase (32-36kDa) fraction of Postia placenta. Postia placenta was grown from agar onto glass coverslips, immunolabeled with or without prior fixation, and examined by SEM. Enzymes were localized on the hyphal surface and on the clumped fibrillar ...
F Green III, C A Clausen, M J Larsen, T L Highley


The effect of Tween 80 on the growth, morphology, and enzyme secretion of Postia placenta
1990 - IRG/WP 1456
The nonionic surfactant Tween 80 (polyethylene oxide sorbitan mono-oleate) has been reported to increase enzyme production and/or secretion in bacteria and fungi. Such a procedure could greatly facilitate research into the physiology of wood-decay fungi since quantities of available enzyme are often limiting. The brown-rot fungus Postia placenta was grown in a synthetic medium supplemented with 0,...
J A Micales