There are various metabolic processes in living systems which are responsible for the synthesis of many metabolites which can be classified into primary and secondary.
• Primary metabolites are essential for the growth and development of living organisms whereas, secondarymetabolites have diverse functions in defense system, tolerance to abiotic stress, etc.
• Secondary metabolites are used in many industries, such as pharmaceuticals, cosmetics, drugs, food additives, etc. However, these compounds are synthesized in very small amounts in the natural system. Therefore, efforts are being made to scale up the production of these beneficial metabolites using bioprocess engineering.
• Bioreactor or fermenter is an engineered vessel which may provide optimum conditions for the product formation and based on the requirement , different types of bioreactors may be configured in bioprocessing.
• Bioprocessing can be operated through two stages: upstream processing and downstream processing.
• In upstream processing, formulation and sterilisation of the media and equipment take place along with the production of pure, healthy and active culture for inoculation.
• The growth of organisms under optimum conditions for desired product formation takes place in a bioreactor or a fermenter.
• There are three modes of operations in bioprocessing:
(i) batch (closed vessel system),
(ii) (fed-batch) (growth limiting substrate is fed intermittently or continuously) and
(iii) continuous (growth limiting substrate is fed continuously).
• In downstream processing, the product is recovered and purified using various techniques, such as reverse osmosis, distillation, drying, etc.
• Many desired products of animals, plants and microbial origin have been commercialised till date.
