Full use of lignocellulosic biomass for efficient synthesis of l-tyrosine and its analogues by engineering microbial consortia

Abstract

Lignocellulose biorefining has great potential to replace the use of petrochemical resources in the production of fuels and chemicals. However, the full use of lignocellulose, which is depolymerized to yield mainly glucose, xylose, and lignin-derived phenolics, remains challenging. Here, we developed a glucose–xylose–phenolics (GXP) system to fully use lignocellulose for the production of L-tyrosine and its analogues in minimal medium. First, we engineered an Escherichia coli–Escherichia coli consortium carrying a CRISPR/dCas9 interference system to simultaneously use glucose and xylose to support cell growth and produce pyruvate, obtaining 34.3 g L⁻¹ pyruvate with a yield of 0.68 g g⁻¹ sugar. Then, we introduced tyrosine phenol lyase and other biocatalytic enzymes into this consortium to generate the GXP system, which could convert pyruvate and lignin-derived phenolics to L-tyrosine and its analogues. Using this GXP system, 20.8 g L⁻¹L-tyrosine was produced from 12.5 g L⁻¹ phenol with a yield of 86.4%. Using the hydrolysate of the raw material sorghum pith, 0.94 g L⁻¹L-tyrosine was produced from 0.96 g L⁻¹p-coumaric acid with a yield of 88.7%, and 8.1 g L⁻¹ pyruvate remained, corresponding to an overall yield of 0.163 g product g⁻¹ sorghum pith. The development of this GXP system illustrates a strategy for fully utilizing lignocellulosic biomass for the synthesis of value-added chemicals.