Recombinant Human Collagen Gene Engineering, Fermentation And Kinetics Study

The optimization of fermentation technology for the production of human-like collagen by recombinant E.coli was studied. The growth and substrate consumption kinetic model were established. Several separation methods were also attempted.A medium containing 10g/l glucose and 5g/l yeast extract with pH6.8 under flask-scale culture was developed.The optimal speed was 200r/min. Under the 10 liter fermenter scale culture cell would reach its maximum growth when the stirring speed was at 1400r/min; ODeoo of recombinant E.coli could reach 98 with a human-like collagen yield of 29.4% in total protein by means of fed-batch culture in which glucose content was controlled at 10g/l.The optimal process condition of recombinant E.coli expressing human-like collagen in batch and fed-batch fermentation was studied. The growth kinetics wasexpressed as , while the substrate consumption kinetics as . In the course of fed-batch fermentation, the approximateexponential feeding model was developed. The dry cell weight reached 71.02 g/1. The established model agreed satisfactorily with experimental data.The harvested cell was suspended in cell lysis buffer and treated by ultra-sonic for 20 minutes. The concentration of Human-like collagen in liquid would achieve 2.8g/l then, treated by ultra-filtration, its concentration would get 8.2g/l. The recombinant protein separation process was also developed.