Regulatory effects of oxygen transfer on overexpression of recombinant benzaldehyde lyase production by Escherichia coli BL21 (DE3).
Effects of oxygen transfer (OT) on benzaldehyde lyase (BAL) production by recombinant E. coli BL21 (DE3) pLySs were investigated at an air-inlet rate of Q(O)/V(R) = 0.5 vvm and agitation rates of N = 250, 500, 625, and 750/min; and at constant dissolved oxygen (DO) concentrations of C(DO) = 0.04 and 0.08 mol/m(3), on a glucose based defined medium. The highest cell concentration (C(X) = 3.0 kg/m(3)) and volumetric BAL activity (A = 1095 U/cm(3)) were obtained at C(DO) = 0.08 mol/m(3). K(L)a increased with agitation rate and decreased with C(X). The highest K(L)a (= 0.039 s((-1)) was obtained at Q(O)/V(R) = 0.5 vvm and N = 750/min. Damköhler number increased with decrease in agitation rate and increase in C(X), while the effectiveness factor was inversely proportional to C(X). The specific growth rate and the yield coefficients decreased with cultivation time and higher values were obtained in higher agitation rates. Oxygen consumption and glucose consumption for maintenance were changed proportionally and inverse proportionally with the BAL production, respectively.
Department of Chemical Engineering, Industrial Biotechnology and Metabolic Engineering Laboratory, Middle East Technical University, Ankara, Turkey.
Hande
H
Kaya-Celiker
Vahideh
V
Angardi
Pinar
P
Calik
D000332:Aerobiosis; D000446:Aldehyde-Lyases / Q000096:biosynthesis* / Q000235:genetics; D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics; D013997:Time Factors
D000596:Amino Acids; D001426:Bacterial Proteins; D003470:Culture Media; D011994:Recombinant Proteins; D000446:Aldehyde-Lyases; C059416:benzaldehyde lyase; D005947:Glucose; D010100:Oxygen