MBC 414
BIOREACTORS
A bioreactor refers to any manufactured device or system that supports a biologically active
environment. In one case, a bioreactor is a vessel in which a chemical process is carried out
which involves organisms or biochemically active substances derived from such organisms. This
process can either be aerobic or anaerobic. These bioreactors are commonly cylindrical, ranging
in size from litres to cubic metres, and are often made of stainless steel. It may also refer to a
device or system designed to grow cells or tissues in the context of cell culture. These devices
are being developed for use in tissue engineering or biochemical/bioprocess engineering. It is
mainly used in industrial processes to produce pharmaceuticals, vaccines, or antibodies. Also
used to convert raw materials into useful byproducts such as in the bioconversion of corn into
ethanol. The function of the bioreactor is to provide a suitable environment in which an organism
can efficiently produce a target product—the target product might be:
• Cell biomass
• Metabolite
• Bioconversion Product
The sizes of the bioreactor can vary over several orders of magnitudes. The shake flask ( 100 -
1000 ml), laboratory fermenter ( 1 – 50 L), pilot scale (0.3 – 10 m3) to plant scale ( 2 – 500 m3)
are all examples of bioreactors.
Operating Mode of Bioreactors
1. Batch
2. Fed batch
3. Continuous
1. BATCH REACTOR: In this mode, the reactor is filled with medium and the fermentation is
allowed to proceed. When the fermentation has finished the contents are emptied for downstream
, processing. The reactor is then cleaned, re-filled, re-inoculated and the fermentation process
starts again.
2. FED-BATCH REACTOR: In this reactor, fresh media is continuous or sometimes
periodically added to the bioreactor but unlike a continuous reactor, there is no removal. The
fermenter is emptied or partially emptied when reactor is full or fermentation is finished. As with
the continuous reactor, it is possible to achieve high productivities due to the fact that the growth
rate of the cells can be optimized by controlling the flow rate of the feed entering the reactor.
3. CONTINUOUS REACTOR: Continuous reactors: fresh media is continuously added and
bioreactor fluid is continuously removed. The reactor can thus be operated for long periods of
time without having to be shut down due to the fact that the growth rate of the bacteria in the
reactor can be more easily controlled and optimized. It is more productive than batch reactors.
Cells can also be immobilized in continuous reactors, to prevent their removal and thus further
increase the productivity of these reactors.
BIOREACTORS
A bioreactor refers to any manufactured device or system that supports a biologically active
environment. In one case, a bioreactor is a vessel in which a chemical process is carried out
which involves organisms or biochemically active substances derived from such organisms. This
process can either be aerobic or anaerobic. These bioreactors are commonly cylindrical, ranging
in size from litres to cubic metres, and are often made of stainless steel. It may also refer to a
device or system designed to grow cells or tissues in the context of cell culture. These devices
are being developed for use in tissue engineering or biochemical/bioprocess engineering. It is
mainly used in industrial processes to produce pharmaceuticals, vaccines, or antibodies. Also
used to convert raw materials into useful byproducts such as in the bioconversion of corn into
ethanol. The function of the bioreactor is to provide a suitable environment in which an organism
can efficiently produce a target product—the target product might be:
• Cell biomass
• Metabolite
• Bioconversion Product
The sizes of the bioreactor can vary over several orders of magnitudes. The shake flask ( 100 -
1000 ml), laboratory fermenter ( 1 – 50 L), pilot scale (0.3 – 10 m3) to plant scale ( 2 – 500 m3)
are all examples of bioreactors.
Operating Mode of Bioreactors
1. Batch
2. Fed batch
3. Continuous
1. BATCH REACTOR: In this mode, the reactor is filled with medium and the fermentation is
allowed to proceed. When the fermentation has finished the contents are emptied for downstream
, processing. The reactor is then cleaned, re-filled, re-inoculated and the fermentation process
starts again.
2. FED-BATCH REACTOR: In this reactor, fresh media is continuous or sometimes
periodically added to the bioreactor but unlike a continuous reactor, there is no removal. The
fermenter is emptied or partially emptied when reactor is full or fermentation is finished. As with
the continuous reactor, it is possible to achieve high productivities due to the fact that the growth
rate of the cells can be optimized by controlling the flow rate of the feed entering the reactor.
3. CONTINUOUS REACTOR: Continuous reactors: fresh media is continuously added and
bioreactor fluid is continuously removed. The reactor can thus be operated for long periods of
time without having to be shut down due to the fact that the growth rate of the bacteria in the
reactor can be more easily controlled and optimized. It is more productive than batch reactors.
Cells can also be immobilized in continuous reactors, to prevent their removal and thus further
increase the productivity of these reactors.
