Substitution of the glycolytic pathway in Saccharomyces cerevisiae to increase the conversion of sugar into ethanol

• Grant number: 13/26238-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: April 01, 2014
• End date: September 30, 2016
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Andreas Karoly Gombert
• Grantee: Leticia Veloso Ribeiro Franco
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The aim of the project is to change the free-energy conservation in Saccharomyces cerevisiae to increase the conversion of sugar into ethanol. If there is a decrease in the yield of ATP per glucose consumed, a greater fraction of glucose (carbon and energy source) is converted into ethanol and a smaller fraction of biomass is generated (Basso et al. (2011) Metabolic Engineering 13:694-703). Thus, the Embden-Meyerhof-Parnas glycolytic pathway will be replaced by the Entner-Doudoroff pathway in Saccharomyces cerevisiae. The net balance of glycolysis would be 1 mole of ATP per mole of glucose instead of 2 moles of ATP per mole of glucose. It is expected an increase of 13% in the yield of glucose into ethanol of the lineage containing the Entner-Doudoroff pathway compared to the wild type. Considering the current Brazilian production of ethanol, this would mean an increase of nearly 3 billion liters per year. To construct a Saccharomyces cerevisiae strain with the Entner-Doudoroff pathway, three main steps will be performed: (1) insert into S. cerevisiae genes encoding 6-phosphogluconate dehydratase (EDD) and 2-keto-3-deoxy-6-phosphogluconate aldolase (EDA), which are the enzymes necessary for the Entner-Doudoroff pathway to occur; (2) insert into S. cerevisiae a G6PD-dual, which may use either NAD+ or NADP+ as cofactor because of the redox balance of the cell containing the Entner-Doudoroff pathway; (3) delete the gene encoding the enzyme phosphofructokinase-1 (PFK1) to stop the flow through the Embden-Meyerhof-Parnas pathway. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

FRANCO, LETICIA VELOSO RIBEIRO. Overexpression of CDC48 e HSP104 in the yeast Saccharomyces cerevisiae.. 2016. Doctoral Thesis - Universidade de São Paulo (USP). Escola Politécnica (EP/BC) São Paulo.