Kaya-Celiker Hande, Angardi Vahideh, Calik Pinar
Department of Chemical Engineering, Industrial Biotechnology and Metabolic Engineering Laboratory, Middle East Technical University, Ankara, Turkey.
Biotechnol J. 2009 Jul;4(7):1066-76. doi: 10.1002/biot.200800255.
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.
在以葡萄糖为基础的限定培养基中，在进气速率Q(O)/V(R) = 0.5 vvm、搅拌速率N = 250、500、625和750/min的条件下，以及在恒定溶解氧（DO）浓度C(DO) = 0.04和0.08 mol/m³的条件下，研究了氧气传递（OT）对重组大肠杆菌BL21（DE3）pLySs生产苯甲醛裂解酶（BAL）的影响。在C(DO) = 0.08 mol/m³时获得了最高细胞浓度（C(X) = 3.0 kg/m³）和体积BAL活性（A = 1095 U/cm³）。K(L)a随搅拌速率增加而增加，随C(X)降低而降低。在Q(O)/V(R) = 0.5 vvm和N = 750/min时获得了最高的K(L)a（= 0.039 s⁻¹）。达姆科勒数随搅拌速率降低和C(X)增加而增加，而有效因子与C(X)成反比。比生长速率和产率系数随培养时间降低，且在较高搅拌速率下获得更高的值。维持所需的氧气消耗和葡萄糖消耗分别与BAL产量成比例地变化和反比例地变化。
