PHARMACEUTICALS
Biomanufacturing uses biological systems to produce commercially relevant molecules at scale , inserting genetic elements into a host capable of producing large quantities of a desired peptide , protein , antibody or small molecule . Selecting the optimal host organism is crucial , as it directly influences the efficiency , yield , quality , safety and environmental impact of products .
Mammalian cells have long been the most popular host platform for the development of biologics . However , scaling up mammalian biomanufacturing processes can be significantly more expensive than using a microbial system due to slower cell growth , expensive media components , higher susceptibility to environmental stresses and complex growth requirements . 1 Moving to a microbial system can therefore reduce scale-up costs , removing financial hurdles to the bioeconomy . 2 For example , the nutrient media required by the methylotrophic yeast P . pastoris is far less expensive than that needed to grow mammalian cells . In addition , thanks to its high-density cell growth , a smaller bioreactor can be used to produce a larger quantity of protein , further helping to reduce overhead costs . P . pastoris has been given GRAS ( generally regarded as safe ) status , making it suitable for the GMP-compliant manufacture of medicines , vaccines and industrial enzymes .
Productive & scalable
P . pastoris is highly scalable , and achieves greater cell densities during fermentation than other microorganisms , resulting in higher recombinant protein titres . Ingenza has developed extremely reproducible yeast fermentation processes that have demonstrated scalability up to 2.6 million litres , and its industry partners have achieved GMP batches of up to 3,000 litres .
Another reason mammalian cells lines are often chosen for recombinant expression is their ability to produce the complex , human-like , post-translational modifications necessary for correct expression of proteins in their native form . If a host lacks the required cellular machinery to process or fold the protein correctly , the end product may show low expression , instability or catalytic inactivity . 3
As a eukaryote , P . pastoris can perform the key post-translational modifications that prokaryotic organisms like Escherichia coli cannot . These include glycosylation , which helps to improve the solubility and stability of secreted proteins and improves the efficacy and quality of biopharmaceutical products .
Ingenza has several P . pastoris strains featuring deletions that reduce glycosylation and prevent proteolysis . The aim is to decrease the potential immunological response and ensure that recombinant proteins remain intact and functional , respectively , proving the versatility of the organism .
Disulfide bond formation is another key ability that ensures optimal folding , tertiary structure and activity . Highly disulfide-bonded proteins usually cannot be made successfully by expression in E . coli due to the reducing environment of the bacterial cytoplasm . As a result of this , disulfide-bonded proteins must be either refolded from E . coli inclusion bodies or secreted into the periplasmic space , resulting in low yields .
The yeast intracellular folding environment is similar to that of mammalian cells , so P . pastoris has been successfully used to produce large quantities of disulfidebonded proteins , as well as other proteins that cannot typically be expressed in bacteria . 4
Low toxicity & simpler purification
Host organisms often generate impurities during the fermentation process , which must be separated later from the target protein . These include native proteins , DNA , RNA ,
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