Salient Features of Bioreactors

4.1. Salient Features of Bioreactors

The various salient features of ‘bioreactors’ or ‘biotechnological processes’ are as enumerated under :

(1) In the recent past, biotechnological processes (bioprocess technology) is found to use both aggressively and progressively specific cells derived exclusively from higher plants and ani- mals to give rise to several useful and vital products.

Examples :

(a) Plant Cell Culture : It is largely aimed at the adequate formation of secondary prod-

ucts solely, for instance : drugs (antibiotics), flavours, and perfumes.

(b) Animal Cell Culture (Mammalian Cell Culture) : It is mainly concerned with the production of extremely potent and life-saving products, such as : (i) vaccines ; (ii) antibody formation ; and (iii) protein molecules e.g., interferon, interleukins etc.

(2) It has been amply demonstrated, proved and established beyond any reasonable doubt that the aforesaid ‘bioproducts’ cannot be produced economically via other chemical processes. Besides, with the advent of latest developments in the specific fields of genetic engineering (or ‘organisms’) and technological advances (in processing modes) one may accomplish wonderful viable economies in the production of ‘bioproducts’.

Examples :

(a) Huge quantum of cells are magnificently grown under well-defined stringent controlled conditions, whereby the ‘organisms’ may be adequately cultivated and motivated to produce the desired products by the help of a precise physical/technical containment system (i.e., bioreactor) in addition to the appropriate medium composition and the specific environment growth regulating parameters, for instance : aeration and temperature.

(b) Articulated optimization of various streams of the ‘bioprocess’ spans not only the pre- vailing biosystems but also the ensuing technical systems. In actual practice, the careful and proper exploitation of an organism’s potential to produce apparently distinct di- vergent products having well-defined characteristic features, quality parameters and in huge quantum will necessarily require the in-depth knowledge of the biochemical mechanisms of product generation duly.

(3) Importantly, the same apparatus, of course with certain modifications, may be used to bring into being several vital products e.g., antibiotic, enzyme, amino acid or single-cell protein. One may look at the bioprocess phenomenon as comprising of several sequential modes of operation, such as : mixing microorganisms with a nutrient broth, allowing the components of react (e.g., yeast cells with a nutrient broth) to give rise to the formation of ethanol.

(4) Most biotechnological procedures are meticulously carried out very much within bioreactors or containment systems’ whereby large excess of cells that are actually invovled in these processes and the bioreactor essentially secures their intimate involvement with the suitable correct dium as well as experimental parameters for the actual growth and product formation.

ANTIBIOTICS

(5) One of the most desired and major functional criterion of a ‘bioreactor’ is to reduce drasti- cally the cost involved in producing a product or providing a service.

A few typical examples having the diverse product categories being produced on a commer- cial scale in bioreactors are summarized as under :

Category

Examples

Cell mass*

Baker’s yeast, single-cell protein

Cell components**

Intracellular proteins

Biosynthetic products** Antibiotics, vitamins, amino and organic acids Catabolic products*

Ethanol, lactic acid, methane

Bioconversion* High fructose corn syrup, 6-amino pencillanic acid (6-APA). Waste treatment

Activated sludge, anaerobic digestion.