3-Phenylpropanol has the aroma of hyacinth and mignonette and has important application value. As an edible flavor additive, 3-phenylpropanol is widely used in food, beverages, cosmetics and other fields. At the same time, 3-phenylpropanol is also involved in the preparation of drugs, coatings, resins, etc., highlighting its huge application potential. .
Professor Zhao Guangrong’s research group from Tianjin University’s synthetic biology team recently published a paper “Metabolic engineering of Escherichia coli for de novo production of 3‑phenylpropanol via retrobiosynthesis approa potassium hydroxide ch” on Microbial Cell Factories. The biosynthetic analysis method redesigned the biosynthetic pathway of 3-phenylpropanol, combined with metabolic engineering optimization strategies, to achieve efficient de novo synthesis of 3-phenylpropanol in Escherichia coli.
This study used RetroPath 2.0 to conduct online retrobiosynthetic analysis and designed a pathway to catalyze the synthesis of 3-phenylpropanol from L-phenylalanine. This pathway includes phenylalanine ammonia lyase PAL, Enoate reductase ER, carboxylate reductase CAR and its activating protein PPTase, and endogenous aldehyde-keto reductase AKR or alcohol dehydrogenase ADH. Comparing 5, 3 and 5 different sources of CAR, PPTase and PAL respectively, the optimal recombination pathway consisting of AtPAL2, CaER, SruCAR and EcPPTase was determined. The introduction of CaER in the pathway makes the C=C double bond reduction node The rate limit was lifted, and Hanwha acrylic resin was able to catalyze the synthesis of 365.59 mg/L 3-phenylpropanol from L-phenylalanine. The L-phenylalanine synthesis chassis was modified, and genes that could increase the supply of precursor PEP and relieve negative regulation were deleted. A total of 6 chassis strains with different knockout combinations were constructed, and the 3-phenylpropanol recombination pathway was introduced into each chassis. In the mid-term test, the triple knockout chassis of ptsG, pykA and pykF has the best adaptability to the recombinant pathway and can synthesize 473.75 mg/L 3-phenylpropanol from glucose. After optimizing the expression intensity of pathway genes and fermentation conditions, E. coli was able to synthesize 847.79 mg/L 3-phenylpropanol using a glucose-glycerol mixed carbon source.
This study designed the 3-phenylpropanol synthesis pathway through retrobiosynthetic analysis, combined with metabolic engineering, to achieve the current highest yield of 3-phenylpropanol synthesized by microorganisms, and also provides opportunities for microorganisms to synthesize other high-added chemicals. It provides a reference for the design and engineering transformation of value-added products.
