Ro, Dae-KyunAttia, Mohamed2017-12-182017-12-182012http://hdl.handle.net/1880/106003Bibliography: p. 81-97Hemandulcin, a C 15 sesquiterpene ketone, is a natural sweetener isolated from the leaves of Lippia dulcis, an indigenous plant to the Central America. Hernandulcin is a promising sugar substitute due to its safety and low caloric potential. However, its biosynthesis in L. dulcis remains unknown. The first biochemical step in hemandulcin biosynthetic pathway is the synthesis of (+)-epi-a-bisabolol from famesyl diphosphate, which is presumed to be catalyzed by a unique sesquiterpene synthase in L. dulcis. To identify(+)­epi-a-bisabolol synthase gene in L. dulcis, deep transcript sequencings ( 454 and Illumina) were performed and five potential candidates were identified by bioinformatic analysis. One of these candidates was successfully identified as a-bisabolol synthase by in vivo functional characterization in metabolically engineered yeast. Deep structural analysis of the produced a-bisabolol confirmed its configuration to be ( + )-epi-a-bisabolol, the core skeleton of hemandulcin. Bisabolol yield from the engineered yeast was quantified and kinetic constants of the identified ( + )-epi-a-bisabolol synthase were determined.xi, 111 leaves : ill. ; 30 cm.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.master thesis10.11575/PRISM/5002