Chinese Journal of Chemical Engineering, Vol.13, No.2, 276-279, 2005
Process control for production of human-like collagen in fed-batch culture of Escherichia coli BL 21
Recombinant E. coli BL 21 was cultivated in high cell density to produce human-like collagen. The effects of the feeding of nitrogen source, controlled by an auto on/off-feeding mode with two different cycles of 0.5 min and 4 min intervals, oxygen-enrichment methods and inducement strength on the cell yield and human-like collagen production were investigated. The studies showed that nitrogen source feeding in fast cycle could result in higher human-like collagen production than that in slow cycle; and the feedback regulation of glucose, increase of the pressure of fermentation bioreactor, and supply of oxygen-enriched air could all increase cell yield and human-like collagen production. The effects of inducement strength on protein expression were found important. When OD600 reached 90-100, the cultivation temperature was increased to 42 C to begin induction for 2-3 h, and then shifted to 39 ° C for 5-6 h induction, the cell density and human-like collagen production could reach 96 g-L-1 [DCW (dry cell mass)] and 19.8% (g.g(-1) DCW) respectively.
Keywords:human-like collagen;recombinant Escherichia coli;fed-batch culture;nitrogen oscillation;oxygen enrichment;temperature inducement