Closed‐loop control of fed‐batch cultures of recombinant Escherichia coli using on‐line HPLC

Abstract

This article describes a fully automated system for the on-line monitoring and closed-loop control of a fed-batch fermentation of recombinant Escherichia coli, and presents two case studies of its used in limiting production of unwanted byproducts such as acetic in fed-batch fermentations. The system had two components. The first components, on-line monitoring, comprised an aseptic sampling device, a microcentrifuge, and HPLC System. These instruments removed a Sample from a fermentor, spun it at high speed to separate solid and liquid components, and then automatically injected the supernatant onto an HPLC column for analysis. The second component consisted of control algorithms programmed using the LabView visual programming environment in a control computer that was linked via a remote components were linked so that results from the on-line HPLC were captured and used by the control algorithm was designed to demonstrate coarse feedback control to confirm the operability of the controller. The second case study showed how the system could be used in a more sophisticated feedings strategy providing fine control and limiting acetate concentration to a low level throughout the fermentation. (c) 1994 John Wiley & Sons, Inc.

Very high-level production and export inEscherichia coli of a cellulose binding domain for use in a generic secretion-affinity fusion system

“…As a result, there is a substantial literature describing feeding and fermentation strategies for increasing cell densities (Mori et al, 1979;Robbins and Taylor, 1989;Turner et al, 1994). Fedbatch fermentations offer the possibility of increasing host biomass by an order of magnitude or more relative to conventional batch cultures (Strandberg et al, 1994;Yang, 1992).…”

Control of yeast fed-batch process through regulation of extracellular ethanol concentration

“…Fortunately, due to modern developments in this field, a wide selection of methods are available [9,10], such as flow injection analysis [11], near infrared spectroscopy [12,13], mid-infrared spectroscopy [14][15][16], HPLC [6], inexpensive gas sensors [8], biosensors [17,7,18,19] and mass spectrometry [20].…”

Framework for online optimization of recombinant protein expression in high-cell-densityEscherichia coli cultures using GFP-fusion monitoring

“…Typically, recombinant cells are grown in reactors employing control algorithms designed to maximize cell productivity. In cases where online measurement sensors for glucose and acetate are available, advanced strategies using feedback from the measurements have been implemented (Kleman et al, 1991;Shimizu et al, 1988;Turner et al, 1994). These strategies control recombinant product formation in an indirect manner, usually via the maximization of biomass or minimization of metabolic byproducts.…”