4-Hydroxyvaleric acid(4-HV)holds promise as a sustainable monomer for biodegradable polyesters and liquid transporta-tion fuels.This study achieved high-level 4-HV production from levulinic acid using an antibiotic-fr...4-Hydroxyvaleric acid(4-HV)holds promise as a sustainable monomer for biodegradable polyesters and liquid transporta-tion fuels.This study achieved high-level 4-HV production from levulinic acid using an antibiotic-free,substrate-inducible system in Escherichia coli.Enzymes involved in the conversion of levulinic acid to 4-HV were expressed with a bicistronic design of ribosome binding sites.The engineered strain demonstrated a 28%higher productivity compared to its counter-part,reaching a significant concentration of 107 g/L 4-HV with a production rate of 4.5 g/L/h and a molar conversion of 95%from levulinic acid in fed-batch cultivation.Recombinant cells from the initial cultivation were reused for a second round of biotransformation,demonstrating 73%efficiency of fresh cells.The study identified specific factors contributing to decreased system efficiency,including medium conditions,increased ionic strength,and high product concentration.Overall,the reported system and our findings hold significant potential for cost-effective microbial production of 4-HV at scale from levulinic acid.展开更多
基金National Research Foundation of Korea(NRF)(Grant No.NRF RS-2023-00208026)Innovative science project in 2020 of the Circle Foundation.
文摘4-Hydroxyvaleric acid(4-HV)holds promise as a sustainable monomer for biodegradable polyesters and liquid transporta-tion fuels.This study achieved high-level 4-HV production from levulinic acid using an antibiotic-free,substrate-inducible system in Escherichia coli.Enzymes involved in the conversion of levulinic acid to 4-HV were expressed with a bicistronic design of ribosome binding sites.The engineered strain demonstrated a 28%higher productivity compared to its counter-part,reaching a significant concentration of 107 g/L 4-HV with a production rate of 4.5 g/L/h and a molar conversion of 95%from levulinic acid in fed-batch cultivation.Recombinant cells from the initial cultivation were reused for a second round of biotransformation,demonstrating 73%efficiency of fresh cells.The study identified specific factors contributing to decreased system efficiency,including medium conditions,increased ionic strength,and high product concentration.Overall,the reported system and our findings hold significant potential for cost-effective microbial production of 4-HV at scale from levulinic acid.
