Disposable Bioreactors - Disposable Bioprocessing Systems - page 76

is because the majority of animal and human cells grow serum free and in
suspension, and also because cell culture bioreactor volumes are currently
shrinking due to increased product titers.
When optimized cell densities and product titers must be achieved in the
shortest possible time, cell culture technologists need to be willing to move
away from their gold standard, that is, the use of stirring systems. In addi-
tion to highly instrumented, scalable wave-mixed and stirred single-use bio-
reactors, the use of shaken disposable bioreactors and novel approaches such
as the PBS or the BayShake are on the increase.
It is assumed that the pharmaceutical industry's current drive toward safe,
individualized medicines (e.g., personalized antibodies, functional cells for
cancer, immune and tissue replacement therapies) will contribute to the con-
tinuing growth of disposable bioreactors.
Disposable bioreactors have not played an important role to date in the
cultivation of cells or tissues of plant origin and microorganisms. However,
plant cell biomass, secondary metabolites for pharmaceutical use, cosmet-
ics (e.g., PhytoCELLTec products from Mibelle Biochemistry, Switzerland),
and glycoproteins have already been successfully produced in satisfactory
amounts in disposable bag bioreactors. They have been wave-mixed, stirred,
or pneumatically agitated.
Similarly, for microorganism cultivations, where high-density growth is
often desired, disposable bioreactors ensuring higher power input and oxygen
transfer efficiency should be used. Currently, the user may have access to the
first suitable types recommended for microorganisms, for example, the CELL-
tainer Microbial Bioreactor, the CellMaker Regular, or the microbial version of
the XDR-Disposable Stirred Tank Bioreactor. The Nucleo Bioreactor represents
another suitable bag bioreactor for microorganisms due to its high K L a values
reaching 200 per hour ( Figure 5.12 ).
The Game Changers in Disposable Bioreactor Industry
Clichés aside, every industry goes through game-changing technology,
breakthrough technology, or whatever comes that wakes up the industry to
new ways of doing things. In the field of bioreactors there have been four
events that can be listed as “game changers.”
The history of fermentation dates back to 7000-8000 BCE when the folks
in Georgia and Iran began making wine ( Figure 5.13 ). The game-changing
moment did not come until a crucial experiment was carried out in 1896 by
the German chemist Eduard Buchner. Buchner ground up a group of cells
with sand until they were totally destroyed. He then extracted the liquid that
remained and added it to a sugar solution. His assumption was that fermen-
tation could no longer occur since the cells that had held the ferments were