Expression and characterization of glycolytic enzymes from thermophilic bacteria in Clostridium thermocellum

• Grant number: 22/03642-2
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: September 19, 2022
• End date: September 18, 2023
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Daniel Groban Olson
• Grantee: Daniela Prates Chiarelli
• Supervisor: Lee Howard Lynd
• Host Institution: Centro de Biologia Molecular e Engenharia Genética (CBMEG). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Dartmouth College, United States
• Associated to the scholarship: 21/10434-4 - Pathway improvement for ethanol production by thermophilic bacteria involving pyruvate-ferredoxin oxidoreductase and related enzymes: library development and reintroduction into C. thermocellum, BP.DD

Abstract

Second generation (2G) biofuels are produced from non-food feedstocks, such as agricultural wastes. These fuels are highly valued nowadays as a low-carbon alternative to fossil fuels. Consolidated bioprocessing (CBP) is a leading strategy for low-cost conversion of lignocellulosic biomass into fuels, where biomass solubilization and sugar fermentation are combined in one step. Clostridium thermocellum is a promising candidate for CBP, however, its ethanol fermentation ability needs to be improved. The ethanol production pathway from the anaerobic thermophilic bacterium, Thermoanaerobacterium saccharolyticum, has been demonstrated to produce ethanol at >90% of the theoretical maximum yield and a titer of 70 g/L.. We are interested in transferring the ethanol to pyruvate and the glycolysis pathway from T. saccharolyticum and Zymomonas mobilis - a natural ethanologen with high ethanol productivity and tolerance - into C. thermocellum and analyze if it is possible to overcome the metabolic limitations of these pathways, improving cellobiose hydrolysis, glucose consumption and ethanol titer and yield. (AU)