dc.contributor.advisor |
Munro, P.A. |
en |
dc.contributor.author |
Otter, Donald Edwin |
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dc.date.accessioned |
2020-07-08T04:58:39Z |
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dc.date.available |
2020-07-08T04:58:39Z |
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dc.date.issued |
1987 |
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dc.identifier.uri |
http://hdl.handle.net/2292/52089 |
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dc.description |
Full text is available to authenticated members of The University of Auckland only. |
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dc.description.abstract |
The utilization of lignocellulosic substrates to produce alternative fuels or other chemicals by enzymatic hydrolysis is uneconomic at present due largely to the high cost of producing the cellulase enzymes (Lee et al., 1982). One method of reducing this cost is to recover and recycle the cellulases from both the hydrolysate and the unhydrolysed substrate after hydrolysis. Whereas the former can be readily achieved by countercurrent adsorption onto fresh substrate (Wilke et al., 1976), a viable method for desorbing and recovering the adsorbed cellulase has yet to be elucidated. In the present investigation a method to desorb and recover the bound cellulase enzymes using sodium hydroxide was developed. Up to 45% of the adsorbed cellulase (Avicelase and CMCase) could be recovered from crystalline cellulose by pH adjustment to pH 10.0. At this pH all the bound protein was eluted which suggested that there was significant enzyme inactivation. The presence of small amounts of detergent (0.05% Triton X-100 or Tween 80) enhanced both cellulase elution (up to 65%) and enzyme stability at pH 10. The desorption method was successful with cellulases adsorbed onto both microcrystalline cellulose (Avicel) and lignocellulosic residues (steam-treated aspen and lucerne). A cellulose hydrolysis and cellulase recycle process was proposed. A method to rapidly separate the various components of the cellulase enzyme system from Trichoderma reesei using ion-exchange HPLC was developed. This enabled the fate of the individual proteins to be studied during adsorption onto and desorption from cellulose. The results are discussed in terms of optimizing cellulase usage and thus the overall economics of cellulose hydrolysis. |
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dc.publisher |
ResearchSpace@Auckland |
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dc.relation.ispartof |
PhD Thesis - University of Auckland |
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dc.relation.isreferencedby |
UoA9974710014002091 |
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dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. |
en |
dc.rights |
Restricted Item. Full text is available to authenticated members of The University of Auckland only. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
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dc.title |
Adsorption/desorption of cellulases from cellulose and their characterization by HPLC |
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dc.type |
Thesis |
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thesis.degree.discipline |
Chemical and Materials Engineering |
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thesis.degree.grantor |
The University of Auckland |
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thesis.degree.level |
Doctoral |
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thesis.degree.name |
PhD |
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dc.rights.holder |
Copyright: The author |
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dc.identifier.wikidata |
Q112848088 |
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