Implications of Improvements
The trend in increasing protein expression yields has had broad ramifications throughout biomanufacturing. From lowering construction requirements, to increasing bottlenecks at the downstream end of production, the effects of upstream advances and the availability of more varied expression systems have created options and problems not previously seen.
Looking at biological products in the market and in development, the industry still largely restricts its basic expression systems to the three systems it has been using for decades—CHO cells for mammalian cell culture, E. coli for bacterial expression, and yeasts (mostly Saccharomyces).
With the relatively slow uptake of newer expression systems, many of which offer significantly higher yields and other improvements, the increases in yields now being seen are primarily the result of incremental improvements in these three key systems, including new and optimized vectors, promoters, and cell lines. This is also reflected in the increasing number of companies offering CHO and other common expression system-based bioprocess optimization services.
Increases in expression yields obviously result in cost savings and improved biomanufacturing efficiency. This has also enabled manufacturers to do more with less, and in many cases do it even better. With expression yields expected to continue to increase, the industry will continue to reap these benefits. Increases in yields also affect facility planning and financing. More importantly, increasing yields and the resultant excess capacity provide needed insurance against costly supply disruptions.