As a common expression host, Escherichia coli has received more and more attention due to the recently developed secretory expression system, which offers advantages like reduced downstream bioprocesses and improved product quality. These advantages, coupled with high-density fermentation technology, make it a preferred system for large-scale production of many proteins utilized in industry and agriculture at a reduced process cost. To improve the secretion efficiency of target proteins, various strategies, including signal peptide optimization, periplasmic leakage, and chaperones co-expression have been developed. In addition, the optimization of the fermentation conditions such as temperature, inducer, and medium were also taken into account for the extracellular production in the high-density fermentation to reduce the cost of production. Here, these strategies ranging from genetic engineering to fermentation optimization were summarized for the future guidance of extracellular production of recombinant proteins using E. coli.
Keywords: Escherichia coli; Genetic engineering strategy; High-density fermentation; Secretory expression system.