Comparative transcriptomics between xylose fermenting yeasts through interaction networks

• Grant number: 20/16074-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2021
• End date: December 31, 2022
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Gonçalo Amarante Guimarães Pereira
• Grantee: Alexandra Russolo Cardelli
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The use of fossil fuels to obtain energy is responsible for a large part of greenhouse gas emissions into the atmosphere. This results in an acceleration in the pace of global warming, besides harming the environment and public health due to these gases' polluting characteristics. To solve these problems, global efforts are being directed towards the search for new renewable energy sources. Second generation bioethanol (2G ethanol) appears as a great option because it is a cleaner and renewable source, and does not compromise food security, as it uses lignocellulosic biomass and not food inputs as raw material. However, there are still several bottlenecks that limit the efficiency of 2G ethanol production. One of the problems faced is developing a strain of Saccharomyces cerevisiae capable of consuming the fraction of biomass composed of xylose and resisting the inhibitory compounds released in the pretreatment phases. Through genetic engineering, the two metabolic pathways (xylose isomerase (XI) and xylose reductase/xylitol dehydrogenase (XR/XDH)) that perform this process have already been successfully inserted into S. cerevisiae strains. However, there are still genetic and metabolic bottlenecks that must be optimized for better efficiency in the production of 2G ethanol. Therefore, the objective of this study is, through the use of bioinformatics tools, such as differential expression analysis and gene interaction networks of previously generated RNA-Seq and microarray transcriptomic data, compare the metabolism of xylose fermenting yeasts with the insertion of the XR/XDH and XI pathways under contrasting conditions of 2G ethanol fermentation (glucose vs. xylose). This will enable a better understanding of these metabolic pathways to develop possible solutions for genetic and metabolic bottlenecks in the production of 2G ethanol.