Optimizing flux distribution between the glyoxylate and TCA cycle for efficient tyrosine production from acetate in Escherichia coli

Abstract

Acetate is one of promising feedstocks owing to its cheap price and great abundance. Here, we engineered a previously reported strain, SCK1, for efficient production of tyrosine from acetate. Initially, the acetate uptake and gluconeogenic pathway were amplified to maximize the flux toward tyrosine. As flux distribution between glyoxylate and TCA cycles is critical for efficient precursor supplementation, the activity of the glyoxylate cycle was precisely controlled by expression of isocitrate lyase gene under different-strength promoters. Consequently, the engineered strain with optimal flux distribution produced 0.70 g/L tyrosine with 20% of the theoretical maximum yield which are 60% and 80% increased values of the parental strain. Our strategies would be applicable to the production of various chemicals from acetate in future.​

Keywords: Flux optimization, metabolic engineering, tyrosine, acetate