Improving 3-HP Production from Lignocellulosic Biomass Through User Defined Accelerated Evolution

• Grant number: 25/10188-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: September 29, 2025
• End date: March 28, 2026
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Nádia Maria Vieira Sampaio
• Grantee: Thaís Tereza Aguiar dos Reis
• Supervisor: Chang Liu
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Campinas , SP, Brazil
• Institution abroad: University of California, Irvine (UC Irvine), United States
• Associated to the scholarship: 23/00824-5 - Genome-wide functional mapping of genes underlying 3HP tolerance in yeast, BP.DD

Abstract

The efficient production of second-generation fuels and chemicals from lignocellulosic hydrolysates requires the development of robust biofactories able to metabolize glucose and xylose while withstanding cell inhibitors and high concentration of the final product. Our research group has been engineering a yeast strain able to produce 3-hydroxypropionic acid (3-HP), a relevant building block chemical, from renewable lignocellulosic biomass. We identified that slow xylose metabolism and 3-HP toxicity represent major challenges that hinder the viability of this end-to-end process. In vivo continuous evolution is a powerful approach to improve the function of proteins and enzymes. In contrast to laborious traditional pipelines, which have shown limited success for the targets proposed herein, the orthogonal DNA replication (OrthoRep) system enables radically accelerated evolution of genes under selective pressure in yeast. Here, we will apply this state-of-the-art tool developed in Dr. Chang Liu's laboratory to obtain mutants for two biotechnologically relevant targets: (i) xylose isomerase, which catalyzes a rate-limiting reaction required for xylose uptake, and (ii) a putative organic acid transporter identified in my PhD research (BAP2), which can improve tolerance to both 3-HP and lignocellulosic hydrolysate. By leveraging OrthoRep's capabilities to accelerate the evolution of XI and BAP2, we are positioned to make significant advancements in the metabolic engineering of robust strains capable of higher yields and improved stability in industrial applications.