Microbial expression systems
This page is under construction.
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Objective : To provide a concise resource to customers interested in recombinant expression in non-Escherichia coli hosts
The biopharmaceutical industry originated with exploitation of laboratory strains of Escherichia coli for the production of recombinant proteins. I always wondered why the industry was seemingly reluctant to consider other microbial hosts. Barriers to entry, conservatism and the rapid emergence of kits and reagents for Escherichia coli based molecular biology represent just some of the drivers to sustain dominance.
The familiarity of Escherichia coli as the bacterial expression host is somewhat deceptive since Escherichia coli has multiple undesirable features for biopharmaceutical production (for example endotoxin, acetate production). The question is therefore what alternatives to Escherichia coli are available and what does it take to gain acceptance by biopharmaceutical companies and regulatory authorities ?
In 2005, I had the opportunity to work on a demonstration project for qualification of CMOs with an expression system based on Pseudomonas flourescens : https://www.biospace.com/article/releases/cambrex-corporation-named-first-biopharmaceutical-manufacturing-partner-for-pfenex-expression-technology-tm-from-dowpharma-/
High cell density growth of Pseudomonas flourescens (Pfenex expression system) was simple and soluble expression of the test recombinant protein was easily demonstrated.
I was invited to give a presentation (see above and PDF) in 2007 and predicted the first commercial approval of a recombinant protein using the Pfenex expression system in 2017. My prediction was close, PF708 (teriparatide) was approved by FDA in December 2018. https://www.centerforbiosimilars.com/news/fda-approves-pfenexs-followon-teriparatide-pf708
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In the following pages we will provide a concise but detailed overview of recombinant protein expression in Pseudomonas flourescens and other bacterial systems.
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