Characteristics of fed-batch cultures of recombinant Escherichia coli containing human-like collagen cDNA at different specific growth rates.
Fed-batch cultures of recombinant Escherichia coli BL21 for producing human-like collagen were performed at different specific growth rates (0.1 approximately 0.25 h(-1)) before induction and at a constant value of 0.05 h(-1) after induction by the method of pseudo-exponential feeding. Although the final biomass (around 69 g l(-1)) was almost the same in all fed-batch cultures, the highest product concentration (13.6 g l(-1)) was achieved at the specific growth rate of 0.15 h(-1) and the lowest (9.6 g l(-1)) at 0.25 h(-1). The mean productivity of human-like collagen was the highest at 0.15 h(-1) (0.57 g l(-1)h(-1)) and the lowest at 0.1 h(-1) (0.35 g l(-1 )h(-1)). In the phase before induction, the cell yield coefficient (Y(X/S)) decreased when the specific growth rate increased, while the formation of acetic acid increased upto 2.5 g l(-1) at 0.25 h(-1). The mean product yield coefficient (Y(P/S)) also decreased with specific growth rate increasing. The respiration quotient (RQ) increased slightly with specific growth rate increasing before induction, and the mean value of RQ was around 72%. The optimum growth rate for human-like collagen production was 0.15 approximately 0.2 h(-1).
Fan
Dai D
DD
Department of Chemical Engineering, Northwest University, Xi'an, China. fandaidi@nwu.edu.cn
Luo
Yane
Y
Mi
Yu
Y
Ma
Xiao X
XX
Shang
Longan
L
D019149:Bioreactors / Q000382:microbiology; D002455:Cell Division; D003094:Collagen / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005285:Fermentation; D006801:Humans; D010101:Oxygen Consumption; D011994:Recombinant Proteins / Q000096:biosynthesis*; D013997:Time Factors
D018076:DNA, Complementary; D011994:Recombinant Proteins; D003094:Collagen