Bioreactor Design Types

Bioreactors are considered 3D-culturing vessels with process controls to achieve an optimum environment for cell growth, and higher volumetric productivity than using 2D-culturing vessels. Different bioreactor designs exist to accommodate the growth of different types of cells. Whether the cells grow in adherent mode or suspension mode, or if cells are shear sensitive, or if the cells perform photosynthesis.

The stirred-tank reactor (STR), or continuously-stirred-tank reactor (CSTR) is the prime example of bioreactor design with an impeller for mixing the bulk liquid by stirring. The STR type bioreactor vessel can be fabricated in glass or stainless steel for steam sterilization. They can also be single-use (SU) bioreactors (video HERE for more info). Or they can be glass or plastic reactors with transparent vessels, equipped with UV lamps (photobioreactors), to grow photosynthetic cells (i.e. grow algae or plant cells).

For the SU bioreactors, the culturing vessel can be a hanging plastic bag (click HERE for more info) or a hard-plastic container (click HERE for more info).

The different types of STR design

The STR is not the only type of bioreactor design. There can be hanging-bag photobioreactors to expose the bag to natural UV radiation from the sun (or with UV lamps). Or the culturing bag can lie horizontally (instead of vertical hanging), such as WAVE RM bioreactor, where mixing is made by creation of waves by rocking motion (RM). The convective bioreactor designs avoid the use of an impeller for mixing, and rather rely on mixing by circulation of the bulk liquid, where the circulation is created by pumping a gas into the bioreactor (oxygen, or air, or nitrogen) and the gas forces a convective motion of the liquid. For the vertical-wheel bioreactors, the wheel can be used to either grow adherent cells attached to the wheel (i.e. PBS Biotech bioreactors), or use the paddles of the wheel for liquid circulation and mixing (open ponds).

Other bioreactor designs, different from STR.