Systems Metabolic Engineering to Elucidate and Enhance Intestinal Metabolic Activities of Escherichia coliNissle 1917

Escherichia coliNissle 1917 (EcN) is one of the most widely used probiotics to treat gastrointestinal diseases. Recently, many studies have engineered EcN to release therapeutic proteins to treat specific diseases. However, because EcN exhibits intestinal metabolic activities, it is difficult to predict outcomes after administration. In silicoand fermentation profiles revealed mucin metabolism of EcN. Multiomics revealed that fucose metabolism contributes to the intestinal colonization of EcN by enhancing the synthesis of flagella and nutrient uptake. The multiomics results also revealed that excessive intracellular trehalose synthesis in EcN, which is responsible for galactose metabolism, acts as a metabolic bottleneck, adversely affecting growth. To improve the ability of EcN to metabolize galactose, otsABgenes for trehalose synthesis were deleted, resulting in the ΔotsABstrain; the ΔotsABstrain exhibited a 1.47-fold increase in the growth rate and a 1.37-fold increase in the substrate consumption rate relative to wild-type EcN.