(176aa) Metabolic Engineering of Clostridium Tyrobutyricum for Butyl Butyrate Production

Butyl butyrate has broad applications in foods, cosmetics, solvents, and biofuels. Microbial synthesis of bio-based butyl butyrate has been regarded as a promising approach. Herein, we engineered Clostridium tyrobutyricum ATCC 25755 to achieve de novo biosynthesis of butyl butyrate from various substrates. Through introducing the butanol synthetic and heterologous substrate metabolic pathways, screening alcohol acyltransferases, adjusting transcription of the key genes, efficient supplying the precursors, and optimizing the fermentation conditions, 20-143 g/L butyl butyrate was obtained from glucose, mannitol, cassava starch, sugarcane molasses, or Saccharina japonica hydrolysate. Altogether, this study presents an anaerobic fermentative platform for de novo biosynthesis of butyl butyrate in one step, which lays the foundation for butyl butyrate biosynthesis from renewable biomass feedstock.