Although several enzymes presumed to be part of the delignification/kraft pulp biobleaching system of the white-rot basidiomycete Trametes versicolor have been studied, characterized, and even exploited as pulp treatments, the complete system remains poorly understood. Little is known about which enzymes are essential for delignification, how they are regulated, or whether there remain unknown enzymes essential to wood decay in this system. Auxotrophic mutants of T. versicolor 52J were developed and characterized. Plasmid pUC18 was complemented with the T. versicolor 52J genome to create a gene library. Transformation with this plasmid-gene library converted argB and ade2 auxotrophs of T. versicolor 52J to prototrophy. Attempts to rescue the plasmids responsible were unsuccessful. Several different pre-existing plasmid constructs were examined for their potential as selectable markers on the fungus. One of these, pGPhT, worked well at conferring phleomycin resistance. Given that there are now available partial or complete sequences for four T. versicolor laccases, the single cellobiose dehydrogenase, and a lignin peroxidase isozyme, these genetic tools should be very useful in dissecting the mechanisms of white-rot delignification.

No description available.

This study investigated the conversion of monomeric lignin fragments into cyclohexanols for use as a source of lignin-derived monomers for renewable Nylon 6 production. Lignin-derived monomeric phenolic species was transformed to their cyclohexanol analogs via selective catalytic hydrogenation. A fixed-bed flow reactor was used to evaluate the selective hydrogenation of individual model phenolic species (guaiacol, 4-methylguaiacol or diphenyl ether). The catalyst composition studied was Ni/SiO₂, which was previously shown to form cyclohexanol as an intermediate from phenol. A primary focus was on tuning the reaction conditions to form desired products, while avoiding the formation of bicyclic species which can be precursors to catalyst deactivation, or fully hydrogenated products of lower value. Reaction pathways of guaiacol, 4-methylguaiacol and diphenyl ether were studied. Major products obtained from guaiacol, 4-methylguaiacol and diphenyl ether reactions were 2-methoxycyclohexanone, 4-methylcyclohexanol and cyclohexanol, respectively. Spent catalyst was analyzed for extent of deactivation.

Thesis (Ph. D.)--Oregon Graduate Center, 1989.

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.

Universiẗat, Fak. f. Forstwiss. u. Waldökologie, Diss.--Göttingen, 1999.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 115-126). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 105-116). Also available on the World Wide Web.

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xix, 184 p.; also contains graphics (some col.). Includes abstract and vita. Advisor: Patrick G. Hatcher, Dept. of Chemistry. Includes bibliographical references (p. 168-184).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1987. / Typescript. Vita. Description based on print version record. Includes bibliographical references.