it cover all the types of biorectors or fermenters/fomenter (large size) used in the field of biotechnology

1. Presentedby-
Bhawna Kushawaha
P.hd Biotech
DUVASU(Mathura)

2. Contents
Bioreactor designing
Classification of Bioreactor process
Components/ Parameter of bioreactor
Types of bioreactor
Recent advance in bioreactor design
Application

3. Bioreactor
A bioreactor may refer to a device or system meant to grow animal cells
or tissues in the context of cell culture. These devices are being
developed for use in tissue engineering or biochemical engineering.
Fermenter
Fermenters are well established for the cultivation of microbes ,proteins
,industrial product(acetic acid, alcohol etc.) under monitored ,controlled
environmental and operational conditions up to an industrial scale.

4. Consideration for bioreactor designing
• cell size (10-20µm)
• more fragile .
• grow more slowly than most
bacteria and fungi
• toxic metabolites e.g. ammonium
& lactate produced during growth
Properties of
animal cell that
set constrains
on design of
animal cell
bioreactor :

5. In order to ensure adequate mixing at low stirring speeds, the culture
vessels are designed with a round bottom, which distinguishes them
from the flat-bottom bacterial bioreactors .
Impeller blades which are fitted at the end of mechanical drive shafts are
designed to allow vertical as well as horizontal liquid flow.
Vessel should be made up of glass or stainless steel .

6. Classification of Bioreactor process for suspension culture
1. In terms of process
requirements they are of
following types-
(i) Aerobic
(ii) Anaerobic
(iv)immobilized
cell bioreactors

7. 2. On the basis of mode of operation,
it may be classified as-
Batch e.g -stirred tank bioreactor
Fed batch. e.g- fluidized bed bioreactor
Continuous -An example of a continuous
bioreactor is the chemostat.

8. Characteristics principles of fed-batch and batch
Fed-batch batch

 Continuous medium addition.
Addition of selected components
energy source (e.g. glucose, glutamine),
amino acids, vitamins, salts, metal trace,
growth factors.
Dilution of the by-products, etc.
e.g. toxic lactate, ammonia.
Changing environment for the cells.
lower stability of the product of
interest.
 Alkali addition
 Continuous addition and removal
of medium can not be done.
• Addition of complete medium at
once .
Removal / Dilution of the by-
products can not done .
 Constant environment for the cells
 higher stability of the product of
interest.
 Less alkali addition for pH control

9. Fed-batch batch
 Continuous dilution of the product of
interest  lower concentration
Multiple harvests  variation
In total larger volume of harvest 
increase work load of down-stream
 Smaller bioreactor (up to 500 or
1000 L)
less available, less ‘convenient’
 Technically more complex 
 higher risk for failure
 higher risk for contamination
 accumulation of the product of
interest
Single cell harvest
Smaller/limited harvest
Larger bioreactor (up to 20000 L)
 more available, even reusable
Technically less complex

10. Cell culture dynamics

11. Components/ Parameter of bioreactor
1.Agitation
Agitation is required for homogeneous distribution of cells and
nutrient media in the cells.
it can be done by magnetic stirred ,turbine impeller, marine
impeller.
Maximum stirring rates for suspension – 100-150 rpm
Microcarrier -40 rpm (suspension and anchorage dependent
cells)

13. 2. Aeration
Through bubbling air
Silicon tubing-highly gas permeable
( inconvenient to use)
By medium perfusion-medium is continuously taken from culture
vessel , passed through oxygenation chamber
(risk of o2 toxicity).

14. 3. Baffles-used to prevent vortex formation.
4. Sparger –used to pass air into vessel.
e.g.- porous sparger
orifice sparger
nozzle sparger
5. Foam control-
produced either by agitation or by component used in medium like
protein. foaming cause adhesion of cell to inner surface of vessel. to avoid
foaming antifoams are used . like pluronic f68,liquid paraffin , oil in some
culture.

15. 6.Temperature
Usually set at the same point as the body temp of the host from which
the cell obtained
Cold-blooded vertebrates – 18-25°C
Mammalian cells – 36-37°C
Temp maintained by use of carefully calibrated and frequently checked
incubators

16. 7.pH
Most cells in culture grow best at pH 7.4
Common used buffer bicarbonate-CO2 or HEPES
Keep the pH medium in a range 7-7.4
When using bicarbonate-CO2 buffer, need to regulate the amount of CO2
dissolved in the medium
Done by using an incubator with CO2 control set to provide an
atmosphere with between 2% and 10% CO2.

17. 8.Viscosity
In absence of serum in media ,it is necessary to increase viscosity
of media with the help of carboxymethyle cellulose.
The viscosity can be determined by using commercial available
viscometers, for example, cone and plate viscometers, coaxial
cylinders viscometers, and impeller viscometers.

18. 9.Sterilization
Heating –dry heat -7o c for 1 hr
moist heat -121 c for 30 min
Radiation-kill bacteria as well as virus.
X-ray ,UV ray
Chemicals- formaldehyde ,H2O2, ethylene oxide .
Filtration-syringe filter , depth filter screen filter.

19. 10.Scale up
Scale up means-to increase volume of culture.
Firstly ,it should be done as pilot experiments.
It provide the closer approximation /prediction for the large scale
production about various factor like pH , temp , aeration ,media.
This may save cost ,labour and time.

20. Types of
bioreactor
Stirred types of bioreactor
Air lift bioreactor
Fluidized bed bioreactor
Tower bioreactor
Gaseous phase bioreactor
Continuous bioreactor

21. Stirred tank
bioreactors
It is batch type of bioreactor.
These are closed system with fix volume.
Used for suspension culture.
It is easy to use.
Good temp control and less expensive.
Easy to maintain sterile condition.

23. Air Lift bioreactor
The bioreactor consists of two concentric cylinders.
The inner cylinder being shorter at both ends than the outer, thereby creating an
outer and an inner chamber.
The bottom of the inner chamber carries a sintered steel ring through which 5%
CO2/O2-8% in air is bubbled.
The bubbles rise, carrying the cell suspension with them. O2/CO2 is vented from
the top, and displacement ensures the return of the cell suspension down the outer
chamber.

25. Advantage
Suited for aerobic culture.
Low energy consumption.
No agitator shaft is needed.
Greater heat removal vs stirred tank.
Disadvantage
Greater air throughput and higher pressure needed.
No bubble breaker.

26. Continuous
bioreactor
Chemostate-(chemical
environment is constant) cell
grow at max density when
some nutrient like vitamin , is
growth limiting.
Turbidostate -cells grow to
achieve higher density.

27. Advantage
Generally maintain cells in log phase for longer period.
Process maintain at steady state .
Large amount of production can be done.
Disadvantage
Difficult to maintain pH and temp.

28. Tower
bioreactor
Elongated non - mechanically
stirred Fermenters .
Aspect ratio 6:1 (height :
diameter )
Unidirectional flow of gases .
Used for continues
production .
E.g used for singled cell
protien production.

29. Fluidized bed reactors
(FBB)
Cells are used as biocatalyst in three phase system (solid ,liquid and gas).
Basically particles used in fbb can be of three types-
Inert core in which cell can attached.
Porous particles in which biocatalyst is entrapped.
Cell aggregates or flocs.
Because of the higher density of the microcarriers they can be perfused slowly
from below, at such a rate that their sedimentation rate matches the flow rate.
The beads therefore remain in stationary suspension, perfused by the medium,
constantly replenishing nutrients and collecting the product into a downstream
reservoir.
Gas exchange is external to the reactor, and no mechanical mixing is
required.

30. Advantage
Universal particles mixing.
Uniform temp gradient.
Ability to operate reactor in
continuous state.

32. Downstream processing of
bioreactor
Filtration –surface filtration , depth filtration,
cross flow filtration ,membrane filtration etc.
Centrifugation- difficulty arise due to small
differences in the density of particle and medium .
Ion exchange resins - dextrone , cellulose,
polyamines.
Chromatography- affinity chromatography
,adsorption chromatography.

33. Recent advance in bioreactor
design
The cell seeding of scaffolds is an important step in establishing a 3D
culture in a macroporous scaffold.
Not only seeding at high cell densities, but also a homogeneous
distribution of cells within the scaffold is essential.
As most of the scaffolds have large, interconnected pores, during
seeding, cells are distributed quite uniformly. During cultivation,
medium flow through a construct enhances the mass transfer of
substrates, particularly oxygen to immobilized cells when
interconnected cell free pores are available.

35. The carriers are arranged in a column either packed (fixed
bed) or fluidized (floating bed). The column is permanently
perfused with a conditioned medium from a medium
reservoir, mostly in a circulation loop.
In recent studies, small well-mixed bioreactors (e.g., shake
flasks, stirred vessels, and super spinner) have been
suggested for cell proliferation, in which the cells are grown
on microcarriers .

36. Offline measurement of dissolved oxygen and dissolved
CO2 were done by sampling the chamber using a syringe
and analyzing it using a blood gas analyzer (Radiometer
ABL5).
Cell counts were done by haemocytometer , and product
assays were done by appropriate methods such as ELISA.

37. A perfused flow-chamber bioreactor with a new concept for aeration
has been introduced recently ,in which tissue-specific inserts for
various types of tissue (e.g., cartilage, skin, and bone) can be applied.

40. NASA tissue
cloning bioreactor
In bioreactors in which cells or tissues grow for experimental or
therapeutic purposes, the design is significantly different from
industrial bioreactors.
Many cells and tissues, especially mammalian ones, must have a
surface or other structural support in order to grow, and agitated
environments are often destructive to these cell types and tissues.
NASA has developed a new type of bioreactor that artificially
grows tissue in cell cultures.
NASA's tissue bioreactor can grow heart tissue, skeletal tissue,
ligaments, cancer tissue for study, and other types of tissue.

41. Application
 Genetic Engineering
 Cell Therapy
 Model System
 Viral vaccines
 Monoclonal antibodies
 Recombinant proteins (glycoprotein)
 Cancer Research
 Toxicity Testing
 Drug Screening and Development

42. Questions....????
Thank you
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