Fig. 4

Fermentation conditions optimization of modularized strain YS58(G1-A8-A10-A2)-GDH for 2-PE synthesis. a Comparison of the affection of different concentrations of glucose and l-Phe on 2-PE production with initial OD₆₀₀ ~ 1 and 0.5% of magnesium and potassium ions in medium. b Comparison of the affection of different concentrations of inorganic salts and ascorbic acid on 2-PE synthesis with 4% of glucose and 0.8% of l-Phe. c Affection of inoculum concentrations and cell densities on 2-PE production with 0.5% of magnesium and potassium ions, 4% of glucose and 0.8% of l-Phe