USE OF EVOLUTIONARY ENGINEERING AND OMIC APPROACHES TO OBTAIN MORE ROBUST YEASTS TO LIGNOCELLULOSIC INHIBITORS

• Grant number: 22/02332-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2023
• End date: December 10, 2026
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Thiago Olitta Basso
• Grantee: Thamiris Guerra Giacon
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 23/07553-7 - Quantification of the robustness of industrial yeasts and real-time monitoring of intracellular state, through genetically-encoded biosensors, in the presence of lignocellulosic inhibitors and contaminating bacteria, BE.EP.DR

Abstract

Concern about environmental impacts has increased interest in non-petroleum forms of energy that are technically viable, economically competitive and that cause less impact on the environment, causing a growing demand for ethanol. It is estimated that there may be a 45% increase in ethanol productivity with the increase in new technologies, such as second-generation ethanol (2G). 2G ethanol is produced using agro-industrial, forestry and even municipal waste to obtain lignocellulosic biomass, which is previously treated to release fermentable sugars to obtain ethanol. However, the fermentation of these lignocellulosic hydrolysates still faces many scientific and technological challenges. Pretreatment processes generate a variety of compounds that act as inhibitors of the metabolism of ethanol-producing microorganisms, and thus, reduce fermentation efficiency. In addition to inhibitors, another problem faced both in the production of first-generation (1G) and 2G ethanol is the constant presence of contaminating microorganisms, especially lactic acid bacteria (LAB). In this context, the present proposal aims to obtain strains, both of yeasts and bacteria, tolerant to inhibitors and to identify genes involved in this new phenotype. This will be sought by the use of evolutionary engineering strategies, aiming at a greater tolerance to these inhibitors, as well as the study of the interactions between the two microorganisms. Thus, a natural continuity of this stage would be the subsequent identification of the genetic bases of the evolved lineages, through "omics" analyses. These have the potential to reveal genetic targets that in turn will guide future approaches to metabolic engineering.