Bioreactor, fermentor, Structure, stirrer, impeller, baffles, sparger, compressor, cooling jacket, sensor, Industrial fermentation process, batch fermentation,

1. R. NITHYA, M. Sc., M. Phil., (Ph. D)
ASSISTANT PROFESSOR
DEPARTMENT OF BIOTECHNOLOGY
SRI ADI CHUNCHNAGIRI WOMENS COLLEGE, CUMBUM
THENI DT, TAMIL NADU, INDIA

2. BIOPROCESS TECHNOLOGY
Bioprocess Technology is a more recent
usage to replace fermentation technology.
Bio-processing broadly involves a
multitude of enzyme catalyzed reaction
carried out, by living cells (or cell-free systems)
for industrial purposes.

3. BIOREACTOR / FERMENTER
The heart of fermentation (or bio-processing) technology is the
fermenter (or bioreactor).
A bioreactor is basically a device in which the organisms (cells) are
cultivated and motivated to form the desired product(s).
It is a containment system designed to give right environment for
optimal growth and metabolic activity of the organism.

5. DESIGNING OF BIOREACTOR
The designing of bioreactor is one of the vital steps in the
fermentative production of novel products in industries.
An ideal bioreactor should provide aerobic or anaerobic
environment as required for the growth of the selected microbe.
Stanburg and Whitaker (1984) have suggested certain ideas to
be considered while designing bioreactors. According to them an
ideal bioreactor must have the following salient features.

6. FERMENTER

7. CHARACTERISTICS OF BIOREACTOR
 A bioreactor must have continuous working capacity for a long time.
 It must be some-what larger in size.
 It must have a system for providing proper aeration to the culture.
 It must have a system for giving agitations to the culture.
 It must have a temperature regulating device.
 It must have a system for checking and regulating the pH of the fermentable
medium during the culture.
 It must have the capacity to do work by consuming less energy.

8. CHARACTERISTICS OF BIOREACTOR
 It must avoid the loss of medium through evaporation.
 It must have a smooth internal surface.
 It must be specially constructed for saving labour.
 It must be designed to work for several fermentation processes.
 It must be designed to use the cheapest materials as substrates.
All the fermenters designed in an industry should be similar in their geometry.

9. BIOREACTOR /FERMENTOR
The fermenter is a device used to carry out submerged fermentation. Sometimes,
fermentors are also called bioreactors. There is a quite difference between fermentors and
bioreactors based on the nature of cultivation.
If fermentation is carried out for the purpose of metabolites (e. g. production of
antibiotics or enzymes), the device is used as fermenter.
On the other hand, if fermentation is carried out for the purpose of cell
biomass (e.g. cultivation of organisms for single cell proteins), the device is
used as bioreactor.
A bioreactor is a large vessel that provides a controlled condition suitable for
culture of a specific microbe. Aerobic condition is maintained in bioreactors but
anaerobic condition is maintained in fermentors.

10. STRUCTURE OF A FERMENTER
The fermenter comprises several components which include the following
 Stirrers
 Spargers
 Baffles
 Compressors
 Heating and cooling systems
 Sensors
 Steaming unit

11. STIRRERS
The stirrer is used to agitate the medium constantly and allow even distribution of
air throughout the medium.
The stirrer comprises two parts, namely centre shaft and impellers.
The impellers are fixed at the centre shaft and the shaft is connected
to the electric motor, which rotates the impellers.

12. IMPELLERS
Two types of impellers are used in
industrial fermentation.
Axial impellers and turbine impellers.
The impellers are installed vertically
in the tank.
They are used to disperse gases.

13. IMPELLERS

14. SPARGERS
Spargers are a type of equipment used to introduce
smallest bubbles into a fermenter.
Spargers are of many types based on structure.
The disc spargers are perforated disc;
The orifice spargers are perforated tubes; and
nozzle spargers are tubes with a single pore.

15. The combine spargers are a combination of agitator with sparger. Usually the
perforated disc type spargers act as combine sparger.
During agitation, sterile air is passed though the pores of the sparger which also aerate
the medium. Thus aeration and agitation is carried out in a single device.
SPARGERS

16. BAFFLES
In a fermenter, there is a need for agitation
in both aerobic and anaerobic operations.
Agitators which are centrally mounted
in the fermentation tanks, exhibit poor
mixing characteristics if baffles are absent.
Baffles reduce the time foe reaching
homogeneity.

17. BAFFLES

18. COMPRESSORS
Compressors are necessary in industrial fermentation.
They supply the fermentation tanks with the air necessary to run the process.
Most tanks require a compressor capable of delivering 30 to 400 h .p.

20. COOLING JACKETS
- Cooling jackets are present around
the fermenter vessel.
- There are two types of cooling jackets
vessel type and tube type.
- Based on temperature, either hot or
cold water will be passed through
the water jackets.
- In large fermenters, heating coils
and cooling compressors will be
present along with the pipes.

21. COOLING JACKETS

22. STEAMING UNIT
The steaming unit in the fermenter is a modified autoclave.
Steam produced here is used to sterilize the unit before running the
fermenters and after product recovery.

23. SENSORS
Sensors are device that can detect and
send the signals to the controlling units of a fermenter.
These sensors are used to measure
temperature, pH, dissolved oxygen, etc.
The sensors used for fermentation are quite
different from regular one, they can tolerate
extreme heat and cold.
Co2 Sensor

24. pH PROBE
It is mainly used to detect the pH
of the fermentation medium.
The pH electrode is always
immerses inside the medium.

25. DO PROBE
It is an electrode used to detect the
Dissolved oxygen present in the
fermentation medium.
It should be kept immersed in
the fermentation medium.

26. TYPES OF FERMENTORS
 Stirred tank fermenter
 Airlift Bioreactor
 Tower Fermenter
 Cylindro conical Bioreactor
 Photo bioreactor.

27. STIRRED TANK FERMENTER

28. AIRLIFT BIOREACTOR

29. TOWER FERMENTER

30. CYLINDRO CONICAL BIOREACTOR

31. PHOTO BIOREACTOR

32. PHOTO BIOREACTOR

33. PHOTO BIOREACTOR