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Poster Presentation 2-21
Synthetic Promoters for High Level Gene Expression in Zymomonas mobilis ZM4
Young Jae Jeon, Charles J. Svenson and Peter L. Rogers
Department of Biotechnology, University of New South Wales Samuls Building, Botany Street, Randwick, Sydney, New South Wales 2052, Australia
Telephone: 61-2-9385-3896; Fax: 61-2-9313-6710; E-mail: p.rogers@unsw.edu.au
Metabolically engineered Zymomonas mobilis strains have been developed to enable this efficient ethanol producer to co-ferment glucose and the pentose sugar D-xylose. Comparative kinetic studies of both chromosomally-integrated (C25) and plasmid-bearing (CP4:pZB5 ZM4:pZB5) strains of recombinant Z. mobilis indicate that expression level of single copy chromosomally-integrated genes is a important factor in the efficient utilization of D-xylose. To date, Z. mobilis promoters have been used to express the two genes of the xylose metabolic operon (xylA and xylB) and the two genes of the pentose phosphate pathway (talB and tktA). Further, only vectors based on native plasmids have so far been successfully use to transform this recalcitrant bacterium.
Here we report the first transformation of Z. mobilis with a non-native based vector, pCJS10. This vector encodes for Green Fluorescent Protein (GFP) under the control of a synthetic constitutive promoter. Flowcytometric analysis of recombinant ZM4: pCJS10 indicates that GFP is expressed at high levels. The plasmid CJS10 is an IncQ vector that can co-exist with the native based vectors, it has an extensive multiple cloning site and encodes for chloramphenicol resistance. Future studies will utilize this vector and a promoterless gfp derivative, pCJS11, to investigate the potential of synthetic constitutive promoters for over expression of xylose assimilation genes in Z. mobilis ZM4.
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