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UBC Theses and Dissertations
Improved pulping efficiency in C4H-F5H transformed poplar Huntley, Shannon Kelly
Abstract
Changes in wood chemistry could have significant impact on both environmental and economic aspects of the pulp and paper industry. Consequently, a considerable amount of effort has been devoted to altering lignin content and/or modifing lignin monomer composition, a cell wall component whose removal is a major part of the chemical pulping process. Analysis of poplar transformed with a cinnamate 4-hydroxylase (C4H):ferulate5-hydroxylase (F5H) construct confirmed significant increases in the mole percent syringyl lignin in transgenic lines. Further, this study demonstrated significant increases in pulping efficiency from greenhouse grown transgenic trees. Compared to wild-type pulp, decreases of 23 kappa units (residual lignin) and increases of >20 ISO brightness units were observed in tree lines exhibiting high syringyl monomer concentrations (93.5% mol S). These changes were associated with no significant change in total lignin content or observed phenotypic differences in the trees. Additionally, pulp yields were not affected by the enhanced removal of lignin.. Furthermore, transgenic lines exhibit reduced fibre coarseness and increased cellulose viscosity. These results suggest that C4H-F5H transformed trees could be used to produce pulp for paper with substantially less severe delignification conditions (lower chemical loading or less energy), and that the pulp produced is of comparable quality to that of the wild-type poplar. Consequently, the ecological footprint left on the environment, measured by the amount of deleterious pulping by-products released into the environment may be significantly reduced.
Item Metadata
| Title |
Improved pulping efficiency in C4H-F5H transformed poplar
|
| Creator | |
| Publisher |
University of British Columbia
|
| Date Issued |
2003
|
| Description |
Changes in wood chemistry could have significant impact on both environmental and economic
aspects of the pulp and paper industry. Consequently, a considerable amount of effort has been
devoted to altering lignin content and/or modifing lignin monomer composition, a cell wall
component whose removal is a major part of the chemical pulping process. Analysis of poplar
transformed with a cinnamate 4-hydroxylase (C4H):ferulate5-hydroxylase (F5H) construct
confirmed significant increases in the mole percent syringyl lignin in transgenic lines. Further,
this study demonstrated significant increases in pulping efficiency from greenhouse grown
transgenic trees. Compared to wild-type pulp, decreases of 23 kappa units (residual lignin) and
increases of >20 ISO brightness units were observed in tree lines exhibiting high syringyl
monomer concentrations (93.5% mol S). These changes were associated with no significant
change in total lignin content or observed phenotypic differences in the trees. Additionally,
pulp yields were not affected by the enhanced removal of lignin.. Furthermore, transgenic lines
exhibit reduced fibre coarseness and increased cellulose viscosity. These results suggest that
C4H-F5H transformed trees could be used to produce pulp for paper with substantially less
severe delignification conditions (lower chemical loading or less energy), and that the pulp
produced is of comparable quality to that of the wild-type poplar. Consequently, the ecological
footprint left on the environment, measured by the amount of deleterious pulping by-products
released into the environment may be significantly reduced.
|
| Extent |
8571898 bytes
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| Genre | |
| Type | |
| File Format |
application/pdf
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| Language |
eng
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| Date Available |
2009-10-29
|
| Provider |
Vancouver : University of British Columbia Library
|
| Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
| DOI |
10.14288/1.0075020
|
| URI | |
| Degree | |
| Program | |
| Affiliation | |
| Degree Grantor |
University of British Columbia
|
| Graduation Date |
2003-11
|
| Campus | |
| Scholarly Level |
Graduate
|
| Aggregated Source Repository |
DSpace
|
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Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.