Regulatory effects of oxygen transfer on overexpression of recombinant benzaldehyde lyase production by Escherichia coli BL21 (DE3)

Abstract

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.

Optimization and kinetic characterization of recombinant 1,3-β-glucanase production in Escherichia coli K-12 strain BL21/pETSD10 - a bioreactor scale study

“…; Kaya‐Çeliker et al . ). The study was conducted at combinations of the agitation rates and an intensity of aeration because the distribution of oxygen to the bacteria in the reactor was also related to the intensity of stirring and bacteria concentration (Çalik et al .…”

“…; Kaya‐Çeliker et al . ). An increase in biomass, protein concentration and 1,3‐ β ‐glucanase activity under the above mentioned conditions was monitored.…”

Recombinant protein production by sucrose‐utilizing Escherichia coli W: untreated beet molasses‐based feeding strategy development

“…Bioreactor experiments were conducted at DO = 40%, at a controlled pH value of 7.2, in V = 3.0 L bioreactor (B.Braun CT2‐2, Germany) that is consisted of temperature, pH, foam, dissolved oxygen, feed inlet, and stirring rate controls with V R = 1.0 L working volume. pH value during the bioprocess was maintained at 7.2 by using 5 mol L −1 KOH or/and 5 mol L −1 H 3 PO 4 .…”

Beet molasses based exponential feeding strategy for thermostable glucose isomerase production by recombinant Escherichia coli BL21 (DE3)

“…Bioreactor experiments were conducted at DO = 40% cascade to air‐flow and agitation rates, at a controlled pH of 7.2, in a V = 3.0 L pilot‐scale bioreactor (Braun CT2–2, Germany) that consisted of temperature, pH, foam, dissolved oxygen, feed inlet, and stirring rate controls with working volume of V R = 1–1.5 L , . pH of the bioprocess was maintained at 7.2 by addition of 5 mol L −1 KOH or/and 5 mol L −1 H 3 PO 4 .…”