Fermentation is done with one of the following method
a) Batch process – in this process, nutrient medium and fermenting organism like yeast are allowed to remain in the bioreactor (fermentation tank) till the maximum fermentation product is produced. The entire medium with organism and the product is removed after each charge. Then the bioreactor is cleaned and a fresh batch is stored.
b) Continuous process – In the process, product is drawn off at regular intervals and fresh medium is introduced into bioreactor
c) Immobilized fermentation process – Living yeast cells are immobilized in calcium alginate beads. The beads with living cells are placed in the nutrient medium in fermentation tank. This technique allows quick fermentation about 20 times faster than the batch process.
CO2 is a bye product of alcohol fermentation. It is collected separately. Yeast cells are also isolated from fermentation product. A part of yeast is kept further inoculation. The remaining part of the yeast is washed, dried and employed as animal feed.
Fermentation process involves two broad groups –
I. Upstream process – All the operations before starting the fermenter are collectively called upstream process such as sterilization of the fermenter, preparation and sterilization of culture medium and the preparation and growth of a suitable inoculums of microbial strain.
II. Downstream process – All the operations after the fermentation are known as downstream process. It includes the purification of fermented products from fermentation broth. Methods commonly used are distillation, centrifugation, filtration, and solvent extaction.
Bioreactor and its type
A bioreactor or fementer is a container designed to provide an optimum environment in which microorganisms or their enzymes can interact with a substrate and form a desired products.
Bioreactors are of two types:-
a) Open type: It allows continuous processing with substance entering at one end and products leaving at the another end.
b) Closed type: In this type, the fermentation is done in batches. Microbes are grown on nutrients placed in vessel at the start of fermentation. The stirred-tank fermenter is a versatile design and is used in a range of sizes from one litre laboratory unit to production-scale vessels of typically 100-ton capacity. Its vessel is cooled by a water jacket. Air is pumped into bottom of the liquid, and acid or alkali added as necessary. A stirrer keeps the contents well mixed. Steam lines are provided so that the vessel can be sterilized after each fermentation batch.
During fermentation it is necessary to regulate many factors within predetermined valves. These O2 and CO2, pH, temperature and media concentration, etc. It is also essential to maintain high degree of sterility within bioreactor. It should be made of stainless steel or copper because such bioreactor is resistant to steam sterilization.
a) Batch process – in this process, nutrient medium and fermenting organism like yeast are allowed to remain in the bioreactor (fermentation tank) till the maximum fermentation product is produced. The entire medium with organism and the product is removed after each charge. Then the bioreactor is cleaned and a fresh batch is stored.
b) Continuous process – In the process, product is drawn off at regular intervals and fresh medium is introduced into bioreactor
c) Immobilized fermentation process – Living yeast cells are immobilized in calcium alginate beads. The beads with living cells are placed in the nutrient medium in fermentation tank. This technique allows quick fermentation about 20 times faster than the batch process.
CO2 is a bye product of alcohol fermentation. It is collected separately. Yeast cells are also isolated from fermentation product. A part of yeast is kept further inoculation. The remaining part of the yeast is washed, dried and employed as animal feed.
Fermentation process involves two broad groups –
I. Upstream process – All the operations before starting the fermenter are collectively called upstream process such as sterilization of the fermenter, preparation and sterilization of culture medium and the preparation and growth of a suitable inoculums of microbial strain.
II. Downstream process – All the operations after the fermentation are known as downstream process. It includes the purification of fermented products from fermentation broth. Methods commonly used are distillation, centrifugation, filtration, and solvent extaction.
Bioreactor and its type
A bioreactor or fementer is a container designed to provide an optimum environment in which microorganisms or their enzymes can interact with a substrate and form a desired products.
Bioreactors are of two types:-
a) Open type: It allows continuous processing with substance entering at one end and products leaving at the another end.
b) Closed type: In this type, the fermentation is done in batches. Microbes are grown on nutrients placed in vessel at the start of fermentation. The stirred-tank fermenter is a versatile design and is used in a range of sizes from one litre laboratory unit to production-scale vessels of typically 100-ton capacity. Its vessel is cooled by a water jacket. Air is pumped into bottom of the liquid, and acid or alkali added as necessary. A stirrer keeps the contents well mixed. Steam lines are provided so that the vessel can be sterilized after each fermentation batch.
During fermentation it is necessary to regulate many factors within predetermined valves. These O2 and CO2, pH, temperature and media concentration, etc. It is also essential to maintain high degree of sterility within bioreactor. It should be made of stainless steel or copper because such bioreactor is resistant to steam sterilization.
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