The following report with recommendations is the result of an expert panel meeting on soft sensor applications in bioprocess engineering that was organized by the Measurement, Monitoring, Modelling and Control (M3C) Working Group of the European Federation of Biotechnology - Section of Biochemical Engineering Science (ESBES). The aim of the panel was to provide an update on the present status of the subject and to identify critical needs and issues for the furthering of the successful development of soft sensor methods in bioprocess engineering research and for industrial applications, in particular with focus on biopharmaceutical applications. It concludes with a set of recommendations, which highlight current prospects for the extended use of soft sensors and those areas requiring development.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/biot.201100506

Soft sensors in bioprocessing: A status report and recommendations

In situ product recovery: Submerged membranes vs. external loop membranes

The analysis of host cell proteins (HCPs) is one of the most important analytical requirements during bioprocess development of therapeutic moieties. In this review, we focus on the comparison of different methods for the analysis of HCPs and how cell lines, fermentation conditions, and unit operations influence HCP distribution during the process chain. Current guidelines typically require reduction of HCPs to the ppm level, depending on the intended use, the route of administration of the product, and the production system. A range of immunospecific and non-specific methods are available that have been globally accepted by regulatory bodies. Immunospecific methods, such as ELISA, are simple to use in routine analysis and can quantify low levels of HCPs when specific antibodies are available. Non-specific methods are more complex; however, they provide a holistic view of the HCP profile and qualitative information of the composition of HCP in the sample. Different methods for the comparison of bioprocessing strategies during scale-up and purification development are compared herein. The methods include immunospecific methods, such as ELISA, western blot, and threshold, and non-specific methods, such as 2D-DIGE and 2D-HPLC combined with MS.

Host cell protein analysis in therapeutic protein bioprocessing - methods and applications.

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

Here, we have studied the setup of an integrated bioprocess for the production of artificial Malaria vaccine candidates with Pichia pastoris. Production of pharmaceutically relevant proteins such as vaccines has high demands regarding protein processing in the bioreactor and for subsequent purification. To implement this challenging protein expression process, a highly instrumented bioreactor was configured for repeated fed batch cultivations and supplemented with an at-line monitoring of the target protein production via HPLC. The integration of a fast in situ purification of the sensitive products using an expanded bed adsorption for a sequential integrated bioprocess allows cyclic product separation. Thus, a fully automated production of artificial malaria vaccines was achieved.

Fully automated production of potential Malaria vaccines with Pichia pastoris in integrated processing

Devices and methods for Integrated Bioprocessing have been developed for production of recombinant proteins with the yeast Pichia pastoris. In doing so cross flow filtration techniques for cell separation and product concentration are connected directly to high instrumented cultivation processes. These are equipped with on-line measuring techniques for substrates and products, e.g., glycerol, methanol and pyruvate as well as recombinant proteins, e.g., the chemokines 1-8del MCP-1 and vMIP-II. Complex automation structures allow for process development at virtual plants which can be used as the basis for establishing and implementing fully automated real processes. Experiments for determination of reaction kinetics, optimization of productivity in high-cell density cultures and Integrated Bioprocessing are outlined, along with detailed illustration of the realization of the methods at industrial pilot plant scale.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/elsc.200300033

B.-U. Wilhelm

Papers

Production of recombinant proteins with Pichia pastoris in integrated processing

Herstellung rekombinanter Proteine mit Pichia pastoris in integrierter Prozessführung