Make your own Bioreactor
A bioreactor may refer to any manufactured or engineered device or system that supports a biologically active environment.The main function of a fermenter or a bioreactor is to provide a controlled environment for growth of the microorganisms or animal cells, to obtain the desired product. A number of important factors must be kept in mind when designing a bioreactor:
1. The vessel should be capable of operating aseptically for a number of days.
2. Adequate aeration and agitation should be provided to meet the metabolic requirements of the microorganism, without causing any damage to the cells.
3. Power consumption should be as low as possible
4. A system for temperature and pH control should be there.
5. Sampling facilities should be provided so as to void any chances of contamination during sampling.
6. There should be minimal requirement of labour in operating, cleaning, harvesting and maintenance of the bioreactor.
The most commonly used ones are based on the stirred upright cylinder with sparger aeration.
On a small scale, glass bioreactors are used. Glass is useful because it gives a smooth surface, is non-toxic, corrosion proof and is usually easy to examine the interior of the vessel.
Pilot scale or large scale fermenters are much bigger and need to be sterilised in situ. Therefore, the materials used have to be assessed on their ability to withstand pressure sterilisation, corrosion and on their potential toxicity and cost. Such fermenters are constructed of stainless steel to limit corrosion. The corrosion resistance of the stainless steel is dependent on the presence of a thin hydrous oxide layer on the surface of the metal. This film is stabilised by chromium and is considered to be continuous, non-porous, insoluble and self healing. Grades of steel that contain 10% to 13% chromium are considered to be effective for the development of a film. Addition of nickel, molybdenum, tungsten and/or silicone improves the resistance to radiation