Controlling Central Carbon Metabolism for Improved Pathway Yields in Saccharomyces cerevisiae [component]

Engineering control of metabolic pathways is important to improving product titers and yields. 3 Traditional methods such as overexpressing pathway enzymes and deleting competing ones are 4 restricted by the interdependence of metabolic reactions and finite nature of cellular resources. 5 Here, we developed a metabolite valve that controls glycolytic flux through central carbon 6 metabolism in Saccharomyces cerevisiae. In a Hexokinase 2 and Glucokinase 1 deleted strain 7 (hxk2Δ glk1Δ), glucose
more » ... 2Δ glk1Δ), glucose flux was diverted away from glycolysis, and into a model pathway, 8 gluconate, by controlling the transcription of Hexokinase 1 with the tetracycline transactivator 9 protein (tTA). A maximum 10-fold decrease in hexokinase activity resulted in a 50-fold increase 10 in gluconate yields, from 0.7% to 36% mol/mol glucose. The reduction in glucose flux resulted 11 in a significant decrease in ethanol by-production that extended to semi-anaerobic conditions, as 12 shown in the production of isobutanol. This proof-of-concept is one of the first demonstrations in 13 S. cerevisiae of dynamic redirection of glucose from glycolysis and into a heterologous pathway. 14 15
doi:10.1021/acssynbio.5b00164.s001 fatcat:alotpymmqnddbckqgq6un25jvm