[Design and assembly of bio-manufacturing "cell factory"].

The chemical manufacturing industry that uses fossil resources as raw materials, consumes non-renewable resources and also causes damage to the ecological environment, stimulating the development of bio-manufacturing with renewable resources as raw materials. Unlike traditional chemical manufacturing, bio-manufacturing uses cells as a "production workshop", and each process in the "workshop" is catalyzed by enzymes. In addition to mild reaction conditions, the "cell factory" has strong plasticity, and can be used to synthesize various target chemicals according to demand adjustment or reconstitution of metabolic pathways. The design process of the "cell factory" follows the following guidelines: 1) Construct an optimal synthetic route from raw materials to products; 2) Balance the metabolic flux of each reaction in the metabolic pathway, so that the metabolic flux of this pathway is much higher than the primary metabolism of the cells; 3) Precursor supply in the pathway should be sufficient, and adjust multiple precursors supply ratio as needed; 4) enzymatic reactions often involve the participation of various cofactors, smooth metabolic pathways need to balance or regenerate various cofactors; 5) Through genetic modification or process improvement to remove metabolic intermediates and products feedback inhibition to achieve higher yields.