Fermentation and Purification of Recombinant Human Type III Collagen Expressed in <i>Escherichia coli</i>

This article mainly describes a fermentation and purification method for expressing recombinant collagen protein in Escherichia coli. The method comprises constructing engineered bacteria expressing human type III collagen and adopting a strategy of feeding in batches for high-density fermentation. The rapid proliferation of bacterial cells is promoted at 37°C, and then the culture is inoculated into a fermentation tank with different carbon sources for growth. When glycerol is used as the main carbon source, the yield of recombinant collagen protein can reach 0.25 to 0.40 g/L. The method allows exploration of the differences in recombinant collagen production with different carbon sources in order to identify the most suitable fermentation medium component. The human type III collagen produced by the method has the typical structure of collagen, with high cell adhesion and the stability of tissue structure. Therefore, it can be used as the raw material for various collagen products, especially facial fillers, dressings, freeze-dried fibers, and gels. © 2025 Wiley Periodicals LLC. Basic Protocol: Fermentation and purification of recombinant human type III collagen expressed in Escherichia coli.