Stirred Bioreactors

It is undisputed that stirred bioreactors are the most common type of bioreactors for submerged bioprocesses. Stirred bioreactors for biopharmaceuticals, which represent the strongest-growing branch of modern biotechnological products, are the focus of our chapter. They are available in working volumes from milliliters up to 70 m3 and are used for a wide range of expression systems that require aseptic conditions. Based on a brief summary of some basic rules for the construction and operation of stirred bioreactors, this chapter will review key engineering issues that affect the design of aseptic stirred bioreactors. We will also provide readers with some general information on transport phenomena in stirred bioreactors before discussing special design aspects and performance parameters for expression systems (mammalian and microbial cells) that prevail in commercial biopharmaceutical production processes. Special attention will be paid to single-use stirred bioreactors, which may have advantages over their reusable counterparts and have become widely accepted over the past years.