Thesis (M.S.)--Oregon Graduate Center, 1981.

M.S. / Biochemistry / Culture parameters influencing metabolism of synthetic [superscript 14] C-labeled lignin model compounds to [superscript 14] CO2 in defined media by the fungi, Polyporus versicolor and Phanerochaete chrysosporium, were examined. Model compound metabolism was oxygen-dependent. Agitation of the cultures, resulting in formation of mycelial pellets, suppressed [superscript 14] CO2 evolution by P. chrysosporium, to a greater extent than by-P. versicolor. The concentration of nutrient nitrogen was critical; [superscript 14] CO2 evolution was retarded at 12 mM ammonium tartrate relative to 1.2 mM ammonium tartrate. Cultures evolved more [superscript 14] CO2 when grown on xylose than on either glucose or glycerol. Initial glucose at 0.1%concentration was significantly less supportive of growth and [superscript 14] CO2 evolution than cultures with 0.5-1.0% glucose. Studies with cycloheximide, a protein synthesis inhibitor, demonstrated that the lignin model compound degrading enzyme system was constitutive. 4-Methoxyl-[ [superscript 14]C] veratryl alcohol was found to be a catabolic product in the metabolism of 4-methoxyl-[ [superscript 14]C]veratrylglycerol-β-guaiacyl ether and 4-methoxyl-[ [superscript 14]C] veratric acid to [superscript 14]CO2.

M.S. / Biochemistry / The hydroxylation and cleavage of conjugated aryl olefins by horseradish peroxidase and Phanerochaete chrysosporium were investigated, and optimum incubation conditions for the enzyme reaction were developed. Substrate specificity experiments showed that the enzyme specificity corresponded roughly to that exhibited by the fungus, with the exception that P. chrysosporium also readily degraded the mono-substituted m- and p-methoxycinnamyl alcohols to their corresponding anisyl alcohols. The pathways employed by the two systems were shown to be different. [superscript 18]O tracer studies showed that the organism probably utilized the hydroxylation product as an intermediate, confirming earlier reports by other workers. (The peroxidase, however, appears to cleave the olefin directly, in addition to catalyzing the hydroxylation reaction. It is not able to cleave the hydroxylated products.) Both peroxidase and laccase purified from Polyporus versicolor incorporated labeled oxygen only onto the B-carbon of 4-0- ethylisoeugenol, whereas P. chrysosporium incorporated a significant amount at the benzylic carbon. In addition, the ability of the fungus to perform the hydroxylation reaction in the presence of catalase suggests that the phenol oxidase(s) of P. chrysosporium are not the sole catalytic agent(s) in the metabolism of lignin-related aryl olefins.

Thesis (M.S.)--Oregon Graduate Center, 1979.

Thesis--University of Helsinki, 1991. / Includes bibliographical references.

Thesis--University of Helsinki, 1991. / Includes bibliographical references.