Bifunctional utilization of whey powder as a substrate and inducer for β-farnesene production in an engineered Escherichia coli

• The bifunctional utilization of whey powder as substrate and inducer was explored. • Whey powder replaced glucose and IPTG to improve β-farnesene titer. • Whey powder eliminated highly concentrated glucose repression. • The β-farnesene titer was 4.74 g/L using whey powder in the 7 L bioreactor. β-Farnesene can replace petroleum products as specialty fuel to solve the global fuel energy crisis, but its production by Escherichia coli ( E.coli ) using glucose and isopropyl β-D-1-thiogalactopyranoside (IPTG) is costly. Hence, we developed a new strategy to produce β-farnesene by engineered E.coli strain F13 with bifunctional utilization of whey powder. The utilization of whey powder as a substrate ensured the growth of the strain F13, while whey powder could also replace IPTG to induce the production of β-farnesene. In shake flasks, β-farnesene production reached 2.41 g/L by the bifunctional utilization of whey powder as a substrate and inducer, 65.1% higher than that with IPTG and glucose. In the 7 L bioreactor, β-farnesene production reached 4.74 g/L using whey powder, which was 197% of that in shake flasks. Therefore, this new strategy might be an attractive route to broaden the applications of whey powder and achieve the economical production of β-farnesene.