Molecular mechanisms involved in cell signaling and genetic regulation of xylose assimilation in engineered strains of Saccharomyces cerevisiae

• Grant number: 20/02936-7
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: January 01, 2022
• End date: January 31, 2025
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Leandro Vieira dos Santos
• Grantee: Gisele Cristina de Lima Palermo
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 22/08092-0 - Elucidating the signalome profile of industrial S. cerevisiae strains and the convergences between xylose-fermenting pathways to convert agroindustrial residues, BE.EP.DD

Abstract

The world energy matrix is based in fossil resources. Besides being a finite source, the huge use of fossil compounds triggered environmental concerns due to greenhouse gases emissions. Biofuels and biochemicals from biomass (2G) are a renewable and clean energy source essential to achieve the global sustainable development goals established by United Nations. Designing and construction of microbial platforms able to convert the sugars present in biomass to bioproducts is an essential step in the development of 2G technologies. Although engineered strains of the yeast Saccharomyces cerevisiae have being developed over two decades, the five-carbon sugar xylose (C5) fermentation is still lagging the performance on glucose (C6) by the current recombinant strains. Recently, our group developed the first part of a 2G genomic atlas as a result of the FAPESP project 2017/08519-6, identifying new molecular bases related to xylose metabolism and regulation. The genetic modifications identified in the FAPESP project enhanced xylose conversion to bioproducts in C5 evolved strains. In this context, the current work seeks to study and elucidated the molecular mechanisms that explain how the identified mutations changes the cell signaling and regulates the xylose sensing and assimilation on evolved strains. In the first part of the project, the CRISPR/Cas9 methodology will be used to validate the SNPs associated to C5 metabolism. Besides, the molecular mechanisms and physiological responses in the C5 mutants will be addressed by multi-omics approaches. The interactions between the different metabolic pathways identified on FAPESP 2017/08519-6 will support a better understanding of microbial C5 metabolism and the complex signaling network that regulates xylose fermentation. In the second part of the project, the PhD candidate will realize a BEPE in collaboration with Lund University to construct a panel of in vivo fluorescent biosensors that allows single-cell real-time monitoring of the signal patterns of the three main sugar sensing pathways in yeast. The developed platform will be used to investigate how the identified mutations changes cell signaling, xylose sensing and assimilation by the yeast. The information obtained with this project will be applied to the rational development and improvement of microbial platforms aiming efficient conversion of 2G sugars into bioproducts. (AU)