Bioreactor and applications of bioreactors

What is a bioreactor:?
An closed apparatus use for growing organisms (yeast, bacteria, or animal cells) under controlled conditions.
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.

1. Page 1 Chapter: 08 BIOREACTOR & ITS APPLICATIONS Amjad Khan Afridi

2. Page 2 What is a bioreactor:? An closed apparatus use for growing organisms (yeast, bacteria, or animal cells) under controlled conditions. 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. BI O RE A CTOR

3. Page 3 A bioreactor is a closed vessel in which a chemical process is carried out which involves organisms or biochemically active substances derived from such organisms. BI O RE A CTOR

4. Page 4 They are systems or devices that supports a biologically active environment They can be either aerobic or anaerobic They are commonly cylindrical, ranging in size from liters to cubic meters, and are often made of stainless steel They supply a  homogeneous  (same throughout) environment by constantly stirring the contents. They give the cells a  controlled  environment by ensuring the same temperature, pH, and oxygen levels. More basics about bioreactors

5. Aerobic bioreactor: Need adequate mixing and aeration. Anaerobic bioreactor: no need for sparging or agitation.

6. Page 6 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 Transformed Product

7. Page 7 The performance of any bioreactor depends on the following key factors: Agitation rate Oxygen transfer Temperature Foam production pH

8. The vessel – capable of being operated aseptically for a number of days. Adequate aeration and agitation – meet requirements of microbes Aeration provide microorganisms in submerged culture with sufficient oxygen for metabolic requirements. Agitation is the mixing or uniform suspension of microbial cells in homogeneous nutrient medium Structural components involved in aeration and agitation are; Agitator (impeller) Baffles Aeration system (sparger) Bioreactor Should Have Following Qualities Page 8

9. Power consumption should be as low as possible. Temperature control and pH should be provided. Sampling facilities should be provided. Evaporation losses from fermenter should not be excessive. Bioreactor Should Have Following Qualities Page 9

10. Minimal use of labor in operation, harvesting, cleaning and maintenance. Should have internal smooth surfaces . Containment involves prevention of escape of viable cells from a fermenter or downstream equipment. Aseptic operation involves protection against contamination. Bioreactor Should Have Following Qualities Page 10

11. BIOREACTOR DESIGN

12. VESSEL Design Aeration & Agitation Agitator ( Impeller) Baffles Aeration System (Sparger) Materials of constriction Temperature Dissolved Oxygen pH Pressure Foam Control & Monitoring (Probes)

13. In fermentation with strict aseptic requirements it is important to select materials that can tolerate repeated steam sterilization cycles. A bioreactor vessel is an enclosed space in which a biological reaction can occur without being disturbed. Bioreactor vessel can be made of glass , which allows the reaction to be observed, or stainless steel , which allows for a much higher internal pressure.  Assemblies can be added to the bioreactor vessel that allow for stirring, monitoring pressure and/or temperature, and adding or removing samples. . V E SSEL Page 14

14. Glass is useful because it gives smooth surfaces, is nontoxic, corrosion proof and it is easy to examine the interior of the vessel A glass cylinder with stainless-steel top and bottom plates Vessels with two stainless steel plates are also used More expensive. Sterilized in situ. Pilot-scale and industrial scale – stainless steel V E SSEL Page 15

15. Aseptic seal – made between glass and glass, glass and metal or metal and metal joints between bioreactor vessel and a detachable top or base plate. Glass and Stainless Steel Bioreactor Page 16

16. Adequate delivery for temperature control effect design of vessel body . Heat is produced by microbial activity and mechanical agitation. If this heat is not ideal for particular manufacturing process then it may be added to or removed from the system. Provision of heat – by placing the fermenter in thermostatically controlled bath or by use of internal heating coils or by a silicone heating jacket through which water is circulated Silicone jacket consists of double silicone rubber mats wrapped around the vessel with heating wires between the two mats. Cooling surface/cooling water. With increase in size of fermenter, silicone jackets are inadequate to remove heat produced by fermentation process so internal coils ( cooling circuit) are used and cold water is circulated to achieve correct temperature. Temperature Control Page 17

17. Aeration provide microorganisms in submerged culture with sufficient oxygen for metabolic requirements. AERATION Page 19

18. It is mixing or uniform suspension of microbial cells in homogeneous nutrient medium. Mechanical agitation is required in fungal and actinomycete fermentations. AGITATION Page 20

19. Agitator (impeller) Baffles Aeration system (sparger) Structural components involved in aeration and agitation Page 21

20. Achieve mixing objectives – bulk fluid and gas-phase mixing, air dispersion, oxygen transfer, heat transfer, suspension of solid particles and maintaining uniform environment throughout vessel contents. AGITATOR (Impeller) Page 22

21. Impellers Types

22. Baffles incorporated into agitated vessels of all sizes to prevent vortex and to improve aeration efficiency. Metal strips roughly one-tenth of vessel diameter and attached radially to the wall. BAFFLES Page 24

23. B a ff l e

24. A device that introduce air into the liquid medium Used for aerobic respiration Has a pipe with minute holes (1/64 - 1/32 inch or large) Hole – allows air under Pressure to escape into medium Impeller blades disperses air released through sparger into medium AERATION SYSTEM (SPARGER) Page 26

25. Three basic types Orifice sparger – a perforated pipe Nozzle sparger – an open or partially closed pipe Porous sparger - Combined sparger-agitator may be used in laboratory fermenters. AERATION SYSTEM (SPARGER) Page 27

26. Different Designed of S parger Page 29

27. Made of sintered glass, ceramics or metal Used mainly on a large scale fermenters Bubble size produced – 10-100 times larger than pores There is also the problem of the fine holes becoming blocked by growth of the microbial 1. Porous sparger Page 30

28. Single open pipe as a sparger to provide air Provide the stream of air bubbles in high pressure No clogging of pores Should be installed bellow the impeller Modern mechanically stirred fermenters use them 2. Nozzle Sparger Page 31

29. In small stirred fermenters the perforated pipes arranged below the impeller in the form of crosses or rings (ring sparger) In most designs the air holes drilled on the under surfaces of the tubes making up the ring or cross. Sparger holes should be at least 6 mm (1/4 inch) diameter because of the tendency of smaller holes to block and to minimize the pressure drop. 3. Orifice sparger Page 32

30. Foam is produced during most microbial fermentations. Foaming may occur either due to a medium component, e.g., protein present in the medium, or due to some compound produced by the microorganism. Proteins are present in corn-steep liquor, pharma media, peanut meal, soybean meal, etc. Foam Control Page 33

31. In extreme conditions the foam may overflow from the fermenter via the air outlet or sample line resulting in the loss of medium and product The presence of foam may also have an adverse effect on the oxygen-transfer rate. Chances of contamination Foam Control Page 34

32. In extreme conditions the foam may overflow from the fermenter via the air outlet or sample line resulting in the loss of medium and product The presence of foam may also have an adverse effect on the oxygen-transfer rate. Chances of contamination Foam Control Page 35

33. Elimination of foam Additional metering of antifoam based on sensor Mechanical metering of foam Probe is inserted through top of bioreactor Stainless steel rod set at a defined levels above the broth surface When foam rises and touched the probe tip , pump is activated and antifoam is released into bioreactor. Mechanical antifoam devices: Discs Propellers Brushes Hollow cones They are attached to agitator shaft above the broth surface Foam is broken down when it is thrown against the walls of the bioreactors.

34. Maintaining a required temperature for microbial growth is essential for good yield. Variation in temperature may cause damage to microorganisms . Temperature affects the solubility and diffusivity of oxygen in the fermentation broth. Measurement rang of 20oC upto 180oC Electrode body made of stainless steel and highly measuring sensitivity. Temperature probe Page 37

35. Only sterilizable electrodes are used Electrode body is made of glass Measurement range 0 upto13 High sensitiveness The control of pH values is ensured with the help of peristatic pumps. pH Page 38

36. APPLICATIONS OF BIOREACTOR

37. A bioreactor may also refer to a device or system meant to grow cells or tissues in the context of cell culture . These devices are being developed for use in tissue engineering The bioreactor is modular in nature and carry out all the processes of fermentation in a single contained environment. Bioreactor plays a core role in bioprocess . Stirred tank bioreactors are commonly used in fermentation industry. https://www.labunlimited.com/solarisbiotech Applications Page 40

38. Bioreactor plays a core role in bioprocess . Due to simple technology and higher yield solid state bioreactors are widely used in industries. Ethanol fermentation is done by saccharomyces cerevisiae in bioreactor. https://www.labunlimited.com/solarisbiotech Applications Page 41

39. Organic acids e.g. acetic acid and butyric acid are formed in bioreactor by the Eubacterium limosum . Thienamycine an antibiotic also produced in bioreactor. Glucomylase is produced by Auerobasidium pullulans in Applications Page 42

40. 2 nd June, 2021