Development of genetic circuit for autonomous dynamic regulation of 3-hydroxypropionic acid production in yeast.

• Grant number: 25/02680-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2025
• End date: April 30, 2027
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Nádia Maria Vieira Sampaio
• Grantee: Gabriel Arantes Silva
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Campinas , SP, Brazil
• Associated research grant: 20/16759-0 - Synthetic biology tools for scalable production of biorenewable 3-hydroxypropionic acid, AP.JP

Abstract

The efficient conversion of biomass into valuable chemicals by engineered microorganisms is critical for achieving a sustainable future. However, engineering cell metabolism for bioproduction can lead to a significant metabolic burden, challenging the cost-efficient production of many relevant chemicals at industrial scale. Most often, the constitutive expression of biosynthetic pathways competes with endogenous pathways for finite precursors, resulting in reduced biomass formation and productivity. For example, efforts to achieve commercial bio-based production of the building block chemical 3-hydroxypropionic acid (3HP) have led to a cellular overload due to a direct competition between production and biosynthesis of fatty acids, which are essential molecules for cell growth. Recent studies have shown that temporal separation between production and growth phases enabled by modern synthetic biology tools can minimize the costs of production to cells, enabling better growth and higher product formation. Dynamic control over the MCR pathway for 3HP production has the potential to significantly increase product formation since it would directly reduce its competition with the fatty acid biosynthesis pathway required for cellular growth. In this research project, we will investigate whether decoupling the population growth phase from the 3HP production phase cam increase yield and reduce metabolic burden. Two strategies to temporally separate these phases will be explored. First, we will implement a two-stage control strategy, in which we will simultaneously induce the 3HP pathway expression and repress fatty acids production using chemical inducers and repressors at different time points during the late fermentation phase. Second, we will leverage synthetic biology tools to program cells to autonomously switch between growth and production phases. The 3HP yield and growth rate of the strains generated through these two strategies, programmed induced two-stage control and autonomous switch, will be quantified and compared. These control strategies can reduce challenges involving a metabolic overload caused by production and could enable the achievement of higher 3HP titers, constituting a significant step toward industrial scale production.