Todd A. Burnes

Evaluating Isolates of Phanerochaete chrysosporium and Ceriporiopsis subvermispora for Use in Biological Pulping Processes

Summary Decay of birch (Betul papyrifera), aspen (Poplus tremuloides) and loblolly pine (Pinus taeda) wood by 19 isolates of Phanerochaete chrysoporium showed considerable variation in percent weight loss and loss of lignin and wood sugars. Birch and aspen woods are degraded to a greateer extent than loblolly pine wood. Among the isolates tested, a great deal of variation was observed in their ability to preferentiall y degrade lignin. Isolate BKM-F-1767 resulted in the greatest loss of lignin on the deciduous woods tested. Many isolates of P. chrysoporium removed all cell wall components causing a nonselective type fo white rot. In contreast, nine isolates of Ceriporiopsis subvermispora caused moderate weight losses and perferential degradation of lignin in aspen, birch and loblolly pine wood. Less variation among isolates was observed in the cell wall components removed from all woods tested. Lignin losses ranged from 19 to 38% in loblolly pine and 50-80% in aspen and birch wood. Polyacrylamide gel electrophoresis (SDS-PAGE) showed a wide variety of band patterns for extracellular enzymes among isolates of P. chrysosporium, but relatively uniform protien bands among isolates of C. subvermispora . Only a few isolates of P. chrysosporium appear to be strains that preferentially removed large amounts of lignin from wood, whereas all isolates of C. subvermisproa tested are selective lignin degraders on deciduous as well as coniferous wood.

Selection of white-rot fungi for biopulping☆

Abstract Different rates of wood decay and ligninolytic activity were found in wood decayed by various white-rot fungi. Chemical and ultrastructural analyses showed wood decayed by Coriolus versicolor consisted of a nonselective attack on all cell wall components. Lignin degradation was restricted to the cell wall adjacent to hyphae or around the circumference of cell lumina. Decay by Phellinus pini, Phlebia tremellosus, Poria medullapanis and Scytinostroma galactinum was selective for lignin degradation. Secondary walls were void of lignin and middle lamellae were extensively degraded. A diffuse attack on lignin occurred throughout all cell wall layers. Variation in ligninolytic activity was found among strains of Phanerochaete chrysosporium . Differences in weight loss as well as lignin and polysaccharide degradation were also found when wood of different coniferous and deciduous tree species was decayed by various white-rot fungi.

Reduction of Resin Content in Wood Chips during Experimental Biological Pulping Processes

Reduction of Resin Content in Wood Chips during Experimental Biological Pulping Processes By Kurt Fischer, Masood Akhtar, Robert A. Blanchette, Todd A. Burnes, Kurt Messner and T. Kent Kirk 1 Institute for Microbial and Biochemical Technology, USDA Forest Products Laboratory, Madison, Wisconsin, U.S.A. 2 University of Wisconsin Biotechnology Center and Institute for Microbial and Biochemical Technology, USDA Forest Products Laboratory, Madison, Wisconsin, U.S.A. 3 Department of Plant Pathology, University of Minnesota, St. Paul, Minnesota, U.S.A. 4 Technische Universität Wien, Institut für Biochemische Technologie und Mikrobiologie, Wien, Austria

Melanin and perithecial development in Ophiostoma piliferum

Colorless strains of Ophiostoma piliferum are currently being used in large-scale industrial appli- cations as a pretreatment for wood chips before me- chanical pulping to remove pitch and prevent blue stain. The fungus rapidly colonizes nonsterile wood chips and degrades pitch and other compounds (i.e., esterified fatty acids, resin acids, etc.) that are prob- lematic in pulp mills. Colorless strains obtained from single ascospore isolations were melanin deficient and unable to produce perithecia when paired with other colorless isolates of the opposite mating type. Melanin and perithecial development were restored, however, in mycelia grown on media supplemented with an ex- tract of spent culture fluid derived from a pigmented strain of 0. piliferum. The extract, analyzed by high pressure liquid chromatography, contained scytalone, an intermediate of the DHN melanin pathway. Pure scytalone also restored hyphal pigment and perithecial development.

Bacterial Biodegradation of Extractives and Patterns of Bordered Pit Membrane Attack in Pine Wood

ABSTRACT Wood extractives, commonly referred to as pitch, cause major problems in the manufacturing of pulp and paper. Treatment of nonsterile southern yellow pine chips for 14 days withPseudomonas fluorescens, Pseudomonas sp.,Xanthomonas campestris, and Serratia marcescens reduced wood extractives by as much as 40%. Control treatments receiving only water lost 11% of extractives due to the growth of naturally occurring microorganisms. Control treatments were visually discolored after the 14-day incubation, whereas bacterium-treated wood chips were free of dark staining. Investigations using P. fluorescens NRRL B21432 showed that all individual resin and fatty acid components of the pine wood extractives were substantially reduced. Micromorphological observations showed that bacteria were able to colonize resin canals, ray parenchyma cells, and tracheids. Tracheid pit membranes within bordered pit chambers were degraded after treatment with P. fluorescensNRRL B21432. P. fluorescens and the other bacteria tested appear to have the potential for biological processing to substantially reduce wood extractives in pine wood chips prior to the paper making process so that problems associated with pitch in pulp mills can be controlled.

Proteomic Comparison of Needles from Blister Rust-Resistant and Susceptible Pinus strobus Seedlings Reveals UpRegulation of Putative Disease Resistance Proteins

In order to characterize a hypersensitive-like reaction in selected Pinus strobus seedlings to Cronartium ribicola, a proteomic comparison of needles from resistant and susceptible seedlings was undertaken using two-dimensional gel electrophoresis (2-DE). The results revealed 19 polypeptides specific to resistant seedlings and seven of these specific to infected resistant seedlings. There were 13 polypeptides up-regulated (> or = 3-fold increase) in resistant family P327 in comparison to needle tissue from susceptible and mock-inoculated seedlings. Electrospray ionization liquid chromatography and tandem mass spectrometry was used to sequence 11 proteins from the 2-DE gels. Sequences obtained from electrospray ionization liquid chromatography and tandem mass spectrometry were used for MS-BLAST and Pro-ID database searches allowing identification with a 95 to 99% confidence level. Six proteins were determined to be homologs of proteins with known roles in disease resistance, five were determined to be homologs of members of the leucine-rich repeat (LRR) superfamily, and one was a homolog of heat shock protein 90, a protein that serves as a cofactor for certain LRR proteins. This is the first report of members of the LRR family with functional homologs in Pinus strobus and of a molecular basis for white pine blister rust resistance in Pinus strobus.

Epicuticular wax and white pine blister rust resistance in resistant and susceptible selections of eastern white pine (Pinus strobus)

ABSTRACT Epicuticular wax on needles was evaluated for its influence on Cronartium ribicola infection of resistant and susceptible selections of Pinus strobus. Environmental scanning electron microscopy comparisons revealed that needles from a resistant selection of eastern white pine, P327, had a significantly higher percentage of stomata that were occluded with wax, fewer basidiospores germinating at 48 h after inoculation, and fewer germ tubes penetrating stomata than needles from a susceptible selection H111. In addition, needles from seedlings that failed to develop symptoms 6 weeks after inoculation, from a cross between P327 and susceptible parent H109, had a significantly higher percentage of stomata occluded with wax compared with needles from seedlings that developed symptoms. In experiments where epicuticular waxes were removed from needles before seedlings were infected, resistant seedlings without wax developed approximately the same number of infection spots (as measured by spot index) as susceptible seedlings with wax intact. Gas chromatography/mass spectrometry comparisons of extracted epicuticular waxes revealed several peaks that were specific to P327 and not found in susceptible H111 suggesting biochemical differences in wax composition. These results implicate the role of epicuticular waxes as a resistance mechanism in P. strobus selection P327 and suggest a role for waxes in reducing spore germination and subsequent infection through stomatal openings.