Evaluation of software sensors for on-line estimation of culture conditions in an Escherichia coli cultivation expressing a recombinant protein.

Software sensors for monitoring and on-line estimation of critical bioprocess variables have mainly been used with standard bioreactor sensors, such as electrodes and gas analyzers, where algorithms in the software model have generated the desired state variables. In this article we propose that other on-line instruments, such as NIR probes and on-line HPLC, should be used to make more reliable and flexible software sensors. Five software sensor architectures were compared and evaluated: (1) biomass concentration from an on-line NIR probe, (2) biomass concentration from titrant addition, (3) specific growth rate from titrant addition, (4) specific growth rate from the NIR probe, and (5) specific substrate uptake rate and by-product rate from on-line HPLC and NIR probe signals. The software sensors were demonstrated on an Escherichia coli cultivation expressing a recombinant protein, green fluorescent protein (GFP), but the results could be extrapolated to other production organisms and product proteins. We conclude that well-maintained on-line instrumentation (hardware sensors) can increase the potential of software sensors. This would also strongly support the intentions with process analytical technology and quality-by-design concepts.

[1]  U. Rinas,et al.  On-line estimation of the metabolic burden resulting from the synthesis of plasmid-encoded and heat-shock proteins by monitoring respiratory energy generation. , 2001, Biotechnology and bioengineering.

[2]  Krist V Gernaey,et al.  On-line estimation of biomass, glucose and ethanol in Saccharomyces cerevisiae cultivations using in-situ multi-wavelength fluorescence and software sensors. , 2009, Journal of biotechnology.

[3]  Heléne Sundström,et al.  Software sensors for fermentation processes , 2008, Bioprocess and biosystems engineering.

[4]  Ana P. Teixeira,et al.  Advances in on-line monitoring and control of mammalian cell cultures: Supporting the PAT initiative. , 2009, Biotechnology advances.

[5]  S. Carlsen,et al.  Production of recombinant human growth hormone in Escherichia coli: Expression of different precursors and physiological effects of glucose, acetate, and salts , 1990, Biotechnology and bioengineering.

[6]  S Gnoth,et al.  Process Analytical Technology (PAT): batch-to-batch reproducibility of fermentation processes by robust process operational design and control. , 2007, Journal of biotechnology.

[7]  K. Kiviharju,et al.  Biomass measurement online: the performance of in situ measurements and software sensors , 2008, Journal of Industrial Microbiology & Biotechnology.

[8]  A C A Veloso,et al.  Monitoring of fed-batch E. coli fermentations with software sensors , 2009, Bioprocess and biosystems engineering.

[9]  Reinhard Guthke,et al.  Monitoring of transcriptome and proteome profiles to investigate the cellular response of E. coli towards recombinant protein expression under defined chemostat conditions. , 2008, Journal of biotechnology.

[10]  S. Enfors,et al.  Modeling of Overflow Metabolism in Batch and Fed‐Batch Cultures of Escherichiacoli , 1999, Biotechnology progress.

[11]  P. Hagander,et al.  Experience in using an ethanol sensor to control molasses feed-rates in baker's yeast production , 1987 .

[12]  Carl-Fredrik Mandenius,et al.  Recent developments in the monitoring, modeling and control of biological production systems , 2004, Bioprocess and biosystems engineering.

[13]  A Chéruy,et al.  Software sensors in bioprocess engineering , 1997 .

[14]  Rimvydas Simutis,et al.  Fuzzy-aided neural network for real-time state estimation and process prediction in the alcohol formation step of production-scale beer brewing , 1993 .

[15]  Rimvydas Simutis,et al.  Generic model control of the specific growth rate in recombinant Escherichia coli cultivations. , 2006, Journal of biotechnology.

[16]  Armando B. Corripio,et al.  Principles and Practice of Automatic Process Control , 1985 .

[17]  Rimvydas Simutis,et al.  Open-loop control of the biomass concentration within the growth phase of recombinant protein production processes. , 2006, Journal of biotechnology.

[18]  U. Scheffler,et al.  Production of Recombinant Proteins with Pichia pastoris in Integrated Processing , 2003 .

[19]  R. P. Cox,et al.  On-line growth measurements in bioreactors by titrating metabolic proton exchange , 1994, Applied Microbiology and Biotechnology.

[20]  Poul Harremoës,et al.  Software sensors based on the grey-box modelling approach , 1996 .

[21]  Carl-Fredrik Mandenius,et al.  Bioprocess control from a multivariate process trajectory , 2004, Bioprocess and biosystems engineering.

[22]  Thomas Scheper,et al.  A review of non-invasive optical-based image analysis systems for continuous bioprocess monitoring , 2010, Bioprocess and biosystems engineering.

[23]  Karl Bayer,et al.  Design of transcriptional fusions of stress sensitive promoters and GFP to monitor the overburden of Escherichia coli hosts during recombinant protein production , 2008, Bioprocess and biosystems engineering.

[24]  Franz Clementschitsch,et al.  Sensor combination and chemometric modelling for improved process monitoring in recombinant E. coli fed-batch cultivations. , 2005, Journal of biotechnology.

[25]  Denis Dochain,et al.  State and parameter estimation in chemical and biochemical processes: a tutorial , 2003 .

[26]  Karl Bayer,et al.  Improvement of bioprocess monitoring: development of novel concepts , 2006, Microbial cell factories.

[27]  Thomas Bachinger,et al.  Gas sensor arrays for early detection of infection in mammalian cell culture. , 2002, Biosensors & bioelectronics.

[28]  K. Kristiansen,et al.  Automatic inducer addition and harvesting of recombinant Escherichia coli cultures based on indirect on-line estimation of biomass concentration and specific growth rate. , 2001, Biotechnology and bioengineering.

[29]  Morten Lykkegaard Christensen,et al.  Growth and proton exchange in recombinant Escherichia coli BL21 , 2002 .

[30]  Govind Rao,et al.  Quantitative measurement of green fluorescent protein expression , 1996 .

[31]  B Sonnleitner,et al.  Growth characteristics of Escherichia coli HB101[pGEc47] on defined medium. , 1998, Biotechnology and bioengineering.

[32]  Carl-Fredrik Mandenius,et al.  Integration of distributed multi-analyzer monitoring and control in bioprocessing based on a real-time expert system. , 2003, Journal of biotechnology.

[33]  Carl-Fredrik Mandenius,et al.  On-line multi-analyzer monitoring of biomass, glucose and acetate for growth rate control of a Vibrio cholerae fed-batch cultivation. , 2005, Journal of biotechnology.

[34]  U. Rinas,et al.  Simple technique for simultaneous on-line estimation of biomass and acetate from base consumption and conductivity measurements in high-cell density cultures of Escherichia coli. , 2000, Biotechnology and bioengineering.

[35]  Carl-Fredrik Mandenius,et al.  Non‐invasive detection of the metabolic burden on recombinant microorganisms during fermentation processes , 2001 .