Exploring the potential of conventional and non-conventional yeasts for enhanced stress tolerance in bioethanol production

• Grant number: 23/02363-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2024
• End date: February 28, 2027
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Marcelo Falsarella Carazzolle
• Grantee: Giovanna Carolina Resk Maklouf Correa
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Bioethanol, obtained by fermenting sugars from energy crops, is the world's most widely used biofuel and its demand is growing. However, increasing its productivity faces several challenges related to cultivation, including limited land availability, negative environmental impacts of intensive agricultural practices, and the need for more robust and productive yeasts. While Saccharomyces cerevisiae has traditionally been used in this sector due to its high efficiency in fermenting hexoses, genetic modifications are required for the consumption of other sugars such as xylose in the production of second-generation ethanol. Additionally, resistance to the inherent stresses of the industrial process is another critical challenge that impairs the microorganism's metabolism, leading to low yields. Therefore, this proposal aims to prospect yeasts with biotechnological potential that have not been extensively explored for this purpose, followed by genetic mapping and metabolic engineering of the selected strain. In the first phase, a library of S. cerevisiae and other non-conventional yeasts will be phenotyped for their thermotolerance, resistance to organic acids, aldehydes, and ethanol, low pH, and growth on different carbon sources. In the second phase, the genetic architecture of the extreme phenotypes found will be characterized through in silico analyses, and synthetic biology techniques will be employed to enable the commercial application of the chosen chassis. This project envisions the development of new strains while investigating possibly neglected resistance mechanisms. The results generated are crucial for the competitiveness of the bioethanol industry, particularly in Brazil, where it is an essential economic pillar.