Recycling Strategy and Repression Elimination for Lignocellulosic-Based Farnesene Production with an Engineered Escherichia coli

• DOI: 10.1021/acs.jafc.9b03907
• Publication Date: 2019-08-07T09:13:22Z
• Authors: Shengping You; Hongxing Chang; Chengyu Zhang; Lan Gao; Wei Qi; Zhiping Tao; Rongxin Su; Zhimin He
• Keywords: 0301 basic medicine; Waste Products; 0106 biological sciences; Hydrolysis; Lignin; Zea mays; 01 natural sciences; 0104 chemical sciences; 12. Responsible consumption; 3. Good health; 03 medical and health sciences; Glucose; Metabolic Engineering; Fermentation; Escherichia coli; Recycling; Sesquiterpenes; 0105 earth and related environmental sciences

Farnesene is an important chemical platform for many industrial products, such as biofuels and polymers. We performed high-efficiency utilization of corncobs for β-farnesene production by separate hydrolysis and fermentation with an optimized Escherichia coli strain. First, we developed a recycling strategy for both corncob pretreatment and cellulose hydrolysis, which saved great amounts of pretreatment reagents and presented a 96.83% cellulose conversion rate into glucose. However, the corncob hydrolysate strongly repressed cell growth and β-farnesene production, being caused by high-concentrated citrate. Through expressing a heterologous ATP citrate lyase and screening for a suitable expression host, an optimized strain was constructed that produced β-farnesene at 4.06 g/L after 48 h in a 5 L fermenter, representing an approximately 2.3-fold increase over the initial strain. Therefore, the proposed strategy about the recycling process and repression elimination was successful and suitable for the production of lignocellulosic-based β-farnesene, which can be further studied to scale up for industrialization.