Engineering synthetic promoters as dynamic controllers in saccharomyces cerevisiae

• Main Author: Teo, Wei Suong
• Other Authors: Chang Wook, Matthew
• Format: Theses and Dissertations
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Chemical engineering::Biotechnology; DRNTU::Engineering::Chemical engineering::Biochemical engineering
• Online Access: https://hdl.handle.net/10356/61754
• Institution: Nanyang Technological University

Metabolic engineering of yeast is an attractive way to produce advanced biofuels. However, engineering of yeast by introducing heterologous proteins and pathways can reduce growth rates and impact productivity. Towards optimizing yeast strains, sensor-regulators can assist the optimal usage of cellular resources, where protein expression can be regulated by the concentration of important metabolites. In this thesis, synthetic promoters were engineered and heterologous transcriptional repressors were expressed in order to create dynamic controllers in yeast. First, fatty acids/fatty acyl-CoA sensor-regulators were made as they are key intermediates in the production of fatty acid derived biofuels, which are suitable for direct use in current transportation infrastructure. This enables fatty acid dependant control of fatty acid derivative producing proteins. Second, AND-gate dynamic controllers that combine inducible promoter function, which enables cells to quickly accumulate biomass before triggering the production of biofuel producing proteins, and fatty acid sensing-regulation were constructed. Third, xylose sensor-regulators were created, where xylose is a major sugar component in the affordable lignocellulose biomass carbon source. This allows regulation of xylose utilizing proteins based on the amount of xylose sugars detected. The function and performance of these synthetic promoters to dynamically control yEGFP reporter protein were demonstrated.