Scale-up of Saccharomyces cerevisiae Fermentation
Scale-up of Saccharomyces cerevisiae fermentation for the manufacture of recombinant human albumin A robust fermentation process for the large scale manufacture of recombinant human albumin for pharmaceutical use is described. It is essential to operate the fermentation in a reproducible and consistent manner because as a secreted product it is potentially exposed to biological or chemical post-translational modification which could result in poor product quality. A process for the production of recombinant human albumin in the yeast Saccharomyces cerevisiae offers a number of advantages. The yeast and mammalian secretion processes are sufficiently similar that correctly folded and processed albumin is obtained in the culture supernatant. The extensive knowledge of S cerevisiae genetics has permitted the development of a stable, plasmid based expression system. This case study demonstrates that yeast episomal plasmids can be wholly suitable for industrial use P2P if they are designed as whole 2mm vectors in a cir° background exemplified by the disintegration vector system. A simple high intensity fed-batch fermentation process has been developed using automatic feed control, which has been applied at the manufacturing scale. Animal derived products are avoided and the production costs are typical of a microbial fermentation based process. Endotoxin removal by ultrafiltration of the medium was shown to be unnecessary. Automation was part of the design from the laboratory development stage, with fermentation and down stream planned as an integrated system avoiding intermediate steps. The resulting process has been successfully scaled-up , most recently to a total working volume of 27,000 litres. The process is reliable for the industrial scale production of pharmaceutical grade recombinant human albumin in S cerevisiae. The robustness of the system has been demonstrated by a process simulation study of genetic stability. No loss of plasmid, product yield or quality was observed even after more than 200 generations of growth.
About the Authors
Ashley Wigley, Novozymes Delta Limited, Nottingham, UK
Mr Ashley Wigley is manager of the technical support and validation groups at Novozymes Delta in Nottingham, UK. His first Degree was in Biochemistry from Imperial College of Science and Technology, London, UK followed by an MSc in Biochemical Engineering from The University of Birmingham (UK). He is also a charted Chemical Engineer and member of IChemE. He joined Novozymes Delta in 1987 and has performed a number of roles including development, scale-up and technology transfer of processes through pilot to cGMP production scale, validation, technical support and new facility design. He left Novozymes Delta for several years in which he gained further experience in process engineering design, construction, commissioning and validation in plasma fractionation, vaccine manufacturing, antibiotic production and biopharmaceutical facilities whilst working for Aventis Behring (Germany) and Jacobs Engineering (UK). He rejoined Novozymes Delta in 2001 as Technical Support Group Manager.
Diane Wilkinson, Novozymes Delta Limited, Nottingham, UK
Dr. Diane Wilkinson’s current post is as the R&D Fermentation Laboratory Manager. Microbiology BSc Leeds (1989), Biochemical Engineering MSc (1990) & Ph.D. UCL (1996). Xenova Ltd (1992), Replizyme Ltd (2002) and Novozymes Delta Ltd. Aalborg University (2000). Scientific Interests includes Fermentation Development and Scale Up, Process Analytical Technologies, Yeast & Filamentous Microbes, Biocatalysis. Diane is also involved in technology transfer and process development.
Dave Mead, Novozymes Delta Limited, Nottingham, UK
Dr. David Mead is Director of Intellectual Property and Business Development at Novozymes Delta Limited, based in Nottingham (UK). His first degree was in Microbiology from the University of Kent, followed by a Ph.D. from UMIST (Manchester, UK) in plasmid-host interactions in yeast. He initially worked as a Research Scientist in Glaxo’s Biotechnology Group, followed by a post-doc in academia (University of Manchester) managing a project between chemistry and molecular biology on superoxide dismutase. Dr. Mead has held a number of roles within Novozymes Delta Limited, including Fermentation Manager with responsibility for the development of commercial and scaleable fermentation processes integrated with molecular biology and downstream purification, including technology transfer, both internally and externally. He was also responsible for setting up and managing the Technical Support function for Recombumin® manufacturing, before taking responsibility for the company’s intellectual property and business development.
Mr Roger Freestone, Director of Engineering at Novozymes Delta in Nottingham, UK
Mr. Freestone holds a BSc in Chemical Engineering from UMIST (Manchester, UK) and is a chartered Chemical Engineer and a member of IChemE. Prior to joining Novozymes Delta in 1987, he worked as a process engineer for RHM Research Limited on mycoprotein processing and for the Boots Company Limited on APIs produced via organic synthesis. His current responsibilities within Novozymes Delta encompass process design, engineering project management and maintenance and calibration within a compliant environment.