A study into the distribution of thermophilic and thermotolerant fungi in a spruce-pine wood chip pile in Prince George was carried out. Five treatments consisting of pine, spruce, incorporation of wood fines into spruce, sterilized spruce and sterilized spruce inoculated with a Ptychogaster sp. were examined. Samples of wood chips buried at six different locations in the chip pile were examined after 3, 6 and 12 months storage periods. From 100 randomly selected chips from each sample the fungi were isolated on 2% malt, 0.5% malic acid and 2% agar at 25° and 45°C. Data on temperature during storage and acidity of wood chips, moisture content and weight loss at the time of sampling were recorded for the six positions in the wood chip pile. Thermophilic fungi colonized the inner regions while thermotolerant fungi inhabited the outer regions of the wood chip pile. Among the thermophilic fungi, listed according to frequency of isolation were Byssochlamys emersonii Stolk-Apinis, Allescheria terrestris Apinis, Sporotrichum thermophile Apinis, Thermoascus aurantiacus Miehe and Humicola lanuginosa (Griffonand Maublanc) Bunce. The most common thermotolerant fungi were Aspergillus fumigatus. Fresenius and Chrysosporium pruinosum (Gilman and Abbot) Comb. Nov. Fungal distribution was generally related to position in the wood chip pile. Of the associated factors temperature (17°-45°C) was most strongly related to fungal distribution, whereas acidity of wood chips and moisture content did not vary greatly between positions. Incubation of wood samples on cultures demonstrated the ability of all the common thermophilic and thermotolerant fungi to cause weight loss of lodge pole pine Pinus contorta Dougl. varlatifolia, ponderosa pine Pinus ponderosa Laws. and spruce Picea glanca (Moench) Voss sap wood samples. These weight losses varied from 0.65% to 25% after six weeks incubation. Temperature, medium and type of wood affected the ability of the fungi to cause weight loss. No synergistic or antagonistic effects' existed between the thermophilic fungi. Chemical analysis of degraded wood indicated that the thermophilic fungi utilized the arabinose fraction of the hemicellulose preferentially. / Forestry, Faculty of / Graduate

M.S. / Biochemistry / The white-rot basidiomycete Phanerochaete chrysosporium produces intracellular soluble and particulate ß-glucosidases and an extracellular ß-glucosidase. The extracellular enzyme is induced by cellulose but repressed in the presence of glucose. The molecular weight of this enzyme is 90,000. The K [subscript m] for -p-nitrophenyl-ß-glucoside is 1.6 x 10[superscript -4] M; the K [subscript 1] for glucose, a competitive inhibitor, is 5.0 x 10[superscript -4] M. The K [subscript m] for cellobiose is 5.3 x 10[superscript -4] M. The intracellular soluble enzyme is induced by cellobiose; this induction is prevented by cycloheximide. The presence of 300 mM glucose in the medium, however, had no effect on induction. The K [subscript m] for p-nitrophenyl- ß -glucoside is 1.1 x 10[superscript -4] M. The molecular weight of this enzyme is about 410,000. Both enzymes have an optimal temperature of 60°C and an E [subscript act] of 9.15 kcal/mole. The pH optima, however, were 7.0 and 5.5 for the intracellular and extracellular enzymes, respectively.

Ganoderma lucidum and G. tsugae are two members of the G. lucidum complex. The authenticity of the two wood-rotting species was demonstrated by comparative studies. Ganoderma lucidum is restricted to hardwoods. Its "smooth" walled basidiospores were characterized by narrow, numerous inter-wall pillars. Isolates of G. lucidum produced chlamydospores in culture and had an average growth of 7.8 mm/da at their optimum temperature range of 30-34 C. Ganoderma tsugae is restricted to conifers. Its basidiospores were "rough" walled and had broad inter-wall pillars. Isolates of G. tsugae did not produce chlamydospores in culture and had an average growth of 2.1 mm/da at the optimum temperature range of 20-25 C. Mating systems were determined for both species as heterothallic and tetrapolar. Interspecific matings of homokaryons were incompatible. Homokaryons of a European G. resinaceum isolate were interfertile with homokaryons from North American collections of G. lucidum. The ability of G. lucidum and G. tsugae to decay wood in vitro was studied using the following woods in agar block decay chambers: grape, oak, mesquite, white fir, and Douglas-fir. Grape wood lost the most weight while mesquite the least. G. lucidum isolates generally caused greater weight loss of all woods than did G. tsugae isolates. 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 but not in oak or Douglas-fir blocks. Scanning electron microscopy demonstrated various stages of selective delignification and simultaneous decay of all woods tested. Isolates of Ganoderma lucidum infected Dog Ridge variety grape plants, grown in the greenhouse, from below-ground wood block inoculations. Twenty-four plants were inoculated: one plant died and 4 other plants declined. After 24 months reisolations yielded only G. lucidum from the five declining plants, demonstrating pathogenicity. The fungus developed in the heartwood and, in later stages, invaded the sapwood. Infected plants developed water stress symptoms with leaves wilting, yellowing, and dying. Field grape plants inoculated with the fungus developed decay columns as large as 42 cm in 17 mons. Decay was limited to the heartwood; no foliar symptoms occurred.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.) in Forestry--University of Maine, 2001. / Includes vita. Includes bibliographical references (leaves 94-102).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1923. / Typewritten. eContent provider-neutral record in process. Description based on print version record.

The heartwood of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) is known to be relatively resistant to attack by wood-destroying fungi. Previous investigations on other species has established various heartwood extractives as the primary deterrents to decay. Several extraneous fractions from Douglas fir were isolated and evaluated for fungicidal activity in order to determine the precise factor influencing the durability of this species. An acetone, ether and water extraction of Douglas fir heartwood meal provided five separate components, namely: a dihydroquercetin, free acid, neutral, phlobatannin and carbohydrate fraction. A bioassay of these materials was made using Fomes annosus (Fr.) Cke., Lentinus lepideus Fr. and Poria incrassata (B.&C.) Curt. as the test fungi. Both a cellulosic and a non-cellulosic substrate were employed. Small wood blocks from which certain extractives had been removed were used for the cellulosic substrates, whereas malt agar impregnated with varying concentrations of the extraneous materials represented the non-cellulosic media. The degree of effectiveness of each component as a fungicide was expressed numerically. Dihydroquercetin was found to be the most potent fungicide, completely inhibiting growth of the most sensitive fungus at a concentration of slightly less than 0.5 per cent. This value compares favorably with experimental results previously reported with phenolic extractives of the genus Pinus. On the basis of these data, timber selected for its high dihydroquercetin content could be expected to have an extended service life when used under conditions favoring decay. The possibility of breeding highly resistant genetic types is also discussed briefly. / Forestry, Faculty of / Graduate

Thujaplicins are the major components in the steam-volatile fraction of western redcedar (Thuja plicata Donn.) (WRC) heartwood extractives. They are consided to be highly toxic to fungi and are chiefly responsible for WRC heartwood decay resistance. This study proves that this traditional concept of toxicity is not completely correct. Thujaplicins are toxic to common decay fungi isolated from decayed WRC wood in living trees or wood in service, such as Poria albipelIucida Baxter. On the other hand, when a fungus such as Sporothrix sp. invades sound heartwood of living WRC, thujaplicins do not provide resistance but instead are altered by that fungus, so that their toxicity to decay fungi is destroyed. Evidence obtained in this study indicates that the mechanism of thujaplicin toxicity to common decay fungi involves the reactive keto-enolic group. As example, thujaplicin toxicity disappears if this reactive group is blocked by laboratory methylation. In living trees detoxification by Sporothrix sp. is demonstrated to involve a process of oxidative dimerization and isomerization of the thujaplicins to a new lactone compound. This compound is proven to have no toxicity to decay fungi, such as Poria albipelIucida Baxter. The dimerization and isomerization destroy the reactivity of the keto-enolic group and thus thujaplicin toxicity. Isolation, purification, and determination of the chemical structure of the new lactone compound produced from thujaplicins during Sporothrix sp. infection was carried out by chemical, chromatographic and spectroscopic methods. This naturally occurring compound has not been isolated previously and there are no previous reports in the literature about a compound with this structure. Following IUPAC rules, the compound is named as 3,3,4,7,7,8-hexamethyl-2,6-dioxa-1,5-anthracene-dione, and given the trivial name 'Thujin'. Biological experiments carried out in this study clearly show that in living WRC trees, fungal attack involves a succession of microorganisms. Three early stage attacking fungi were consistantly isolated from discolored WRC heartwood. They are identified as Sporothrix sp. KirschsteinieIIa thujina (Peck) Pomerleau & Etheridge and Phialophora sp. Biological roles of these fungi are demonstrated based upon the results of wood block bioassays and chemical analysis of wood blocks treated with the three fungal isolates. / Forestry, Faculty of / Graduate

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