Development and Application of Accessory Hemicellulases for the Production of Engineered Polysaccharides

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Master, Emma R., Prof., University of Toronto, Canada Mai-Gisondi, Galina 2017-05-05T09:01:33Z 2017-05-05T09:01:33Z 2017
dc.identifier.isbn 978-952-60-7409-2 (electronic)
dc.identifier.isbn 978-952-60-7410-8 (printed)
dc.identifier.issn 1799-4942 (electronic)
dc.identifier.issn 1799-4934 (printed)
dc.identifier.issn 1799-4934 (ISSN-L)
dc.description.abstract Hemicelluloses such as xylans and galactoglucomannans are thought to serve as crosslinking and bridging macromolecules in nature, and have been considered for applications ranging from prebiotics to films, coatings, and hydrogels. Accessory hemicellulases can be used to control and improve the functional performance this major biomass fraction through fine-tuning branching group chemistry. Accordingly, the overall objective of this thesis was to discover and engineer accessory hemicellulases that could be used to control the branching substituents present in different plant polysaccharides. Herein, the utility of characterized enzymes was demonstrated through chemo-enzymatic synthesis of xylan-based cellulose coatings. First, a new acetyl xylan esterase (AnAcXE) from carbohydrate esterase (CE) family CE1 was biochemically characterized and then fused to a family 3 carbohydrate binding domain (CtCBM3) in an effort to increase catalytic performance on high molecular weight and insoluble substrates, including cellulose acetate and acetylated xylan. Whereas increased binding and increased catalytic performance was observed using cellulose acetate, activity on oligomeric substrates was not affected. AnAcXE was then compared in its action on galactoglucomann and glucuronoxylan with enzymes from families CE6 and CE16. This direct comparative analysis uncovered differences in substrate preference and regio-selectivity of corresponding enzymes. Finally, a new α-arabinofuranosidase from GH62 (SthAbf62A) was comprehensively characterized. Its action on polymeric wheat and rye arabinoxylans containing high degree of substitution was significantly higher than on arabinan and 4-nitrophenyl α-L-arabinofuranose. These analyses indicated that SthAbf62A was a good candidate for selective removal of arabinofuranose linked through α-(1->2) and α-(1->3) to singly substituted xylopyranose in arabinoxylans. Accordingly, SthAbf62A along with the commercial AXHd3 (specific for (1->3) on di-substituted xylopyranose) were used to modify wheat arabinoxylan (WAX) prior to grafting with glycidyl methacrylate. Action of SthAbf62A lowered the water solubility of WAX, which was correlated to higher grafting efficiency. Although the binding efficiency of grafted WAX to regenerated cellulose did not change compared to ungrafted WAX, treatment with SthAbf62A or AXHd3 prior to grafting increased the viscoelastic properties of the stably adsorbed layer, indicating potential usefulness of these enzymes in production of new xylan-based coatings. en
dc.format.extent 94 + app. 78
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher Aalto University en
dc.publisher Aalto-yliopisto fi
dc.relation.ispartofseries Aalto University publication series DOCTORAL DISSERTATIONS en
dc.relation.ispartofseries 82/2017
dc.relation.haspart [Publication 1]: Mai-Gisondi G., Turunen O., Pastinen O., Pahimanolis N., Master E. R. (2015)Enhancement of acetyl xylan esterase activity on cellulose acetate through fusion to a family 3 cellulose binding module. Enzyme Microb Technol 79-80, 27–33. DOI: 10.1016/j.enzmictec.2015.07.001
dc.relation.haspart [Publication 2]: Mai-Gisondi G., Maaheimo H., Chong S-L., Hinz S., Tenkanen M., Master E. R. (2016) Functional comparison of versatile carbohydrate esterases from families CE1, CE6 and CE16 on 4-O-methylglucuronoxylan and acetyl-galactoglucomannan. (submitted in BBA General Subjects)
dc.relation.haspart [Publication 3]: Wang W., Mai-Gisondi G., Stogios P. J., Kaur A., Xu X., Cui H., Turunen O., Savchenko A., Master E. R. (2014) Elucidation of the molecular basis for arabinoxylan-debranching activity of a thermostable family GH62 α-Larabinofuranosidase from Streptomyces thermoviolaceus. Appl Environ Microbiol 80 (17), 5317-5329. DOI: 10.1128/AEM.00685-14
dc.relation.haspart [Publication 4]: Littunen K., Mai-Gisondi G., Seppälä J., Master E. R. (2016) Enzymatically debranched xylans in graft copolymerization. Biomacromolecules, 18 (5), pp 1634–1641. DOI: 10.1021/acs.biomac.7b00229
dc.subject.other Biotechnology en
dc.title Development and Application of Accessory Hemicellulases for the Production of Engineered Polysaccharides en
dc.type G5 Artikkeliväitöskirja fi Kemian tekniikan korkeakoulu fi School of Chemical Technology en
dc.contributor.department Biotuotteiden ja biotekniikan laitos fi
dc.contributor.department Department of Bioproducts and Biosystems en
dc.subject.keyword lignocellulose en
dc.subject.keyword acetyl esterases en
dc.subject.keyword α-arabinofuranosideses en
dc.subject.keyword CBM-fusion en
dc.subject.keyword regio-selectivity en
dc.identifier.urn URN:ISBN:978-952-60-7409-2
dc.type.dcmitype text en
dc.type.ontasot Doctoral dissertation (article-based) en
dc.type.ontasot Väitöskirja (artikkeli) fi
dc.contributor.supervisor Frey, Alexander D., Prof., Aalto University, Department of Bioproducts and Biosystems, Finland
dc.opn Westereng, Bjørge, Dr., Norwegian University of Life Sciences, Norway
dc.rev Lee, Hung, Prof., University of Guelph, Canada
dc.rev Abbott, D Wade, Dr., Agriculture and Agri-Food Canada, Canada 2017-05-19

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