β-Farnesene Production from Low-Cost Glucose in Lignocellulosic Hydrolysate by Engineered <i>Yarrowia lipolytica</i>

Abstract

β-Farnesene is value-added acyclic volatile sesquiterpene with wide applications in energy, industry, and agriculture. Producing high-value-added compounds from low-cost renewable feedstocks in engineered microbial cell factories is an environmentally friendly and economical process for β-farnesene biosynthesis. In this study, the potential for using engineered Yarrowia lipolytica to produce β-farnesene from lignocellulosic hydrolysate as the carbon source was investigated. An efficient biosynthetic pathway for β-farnesene production was established via iterative enhancement of multiple genes based on the high endogenous acetyl-CoA flux in Yarrowia lipolytica. Overexpression of mevalonate pathway genes and screening of β-farnesene synthase resulted in a β-farnesene titer of 245 mg L−1 in glucose media. Additional copies of mevalonate pathway genes and enhanced expression of HMG-CoA reductase and β-farnesene synthase further increased the titer of β-farnesene to 470 mg L−1. In addition, by combining metabolic engineering strategies using the lignocellulosic hydrolysate utilization strategy, the addition of Mg2+ promoted the production of β-farnesene, and the best-performing strain produced 7.38 ± 0.24 g L−1 β-farnesene from lignocellulosic hydrolysate media in a 2 L fermenter after 144 h. This study shows great potential for the sustainable production of β-farnesene from lignocellulosic biomass via engineered Yarrowia lipolytica.

Keywords

• β-Farnesene
• <i>Yarrowia lipolytica</i>
• lignocellulosic hydrolysate
• metabolic engineering
• fed-batch fermentation