Arts: Fermentation in Biotechnology
In beginning, the meaning of fermentation process was the use of microorganisms for the production of food (cheese, yogurt, fermented pickles and sausages, soy sauce), beverages (beers, wines) and spirits. However, in biotechnology the term "fermentation" means the production of any product by the mass culture of micro-organisms.
Application of Fermentation
In fermentation growth of organisms is obtained for the production of desired products of commercial value. Traditionally, only food and beverage products were produced by using fermentation. Now many other products e.g. industrial chemicals are also being produced.
a) Fermented Foods
Fermentation often makes the food more nutritious, more digestible and tastier. It also tends to preserve the food, lowering the need for refrigeration.
The following groups are included in the fermented foods.
i) Cereal products: Bread is the commonest type of fermented cereal product. Wheat dough is fermented by S. cerevisiae with some lactic acid bacteria.
ii) Dairy products: Cheese and yogurt are important fermentation products. Cheese is formed when a milk protein is coagulated. This happens when the acid produced by lactic acid bacteria reacts with milk protein. Yogurt is made from milk by different lactic acid bacteria.
iii) Fruit and vegetable products: Fermentation is usually used, along with salt and acid, to preserve pickle, fruits and vegetables.
iv) Beverage Products: Beer is produced from cereal grains which have been malted, dried and ground into fine powder. Fermentation of the powder is done by yeast. This process breaks the glucose present in powder into pyruvic acid and then into ethanol. Grapes can be directly fermented by yeasts to wine.
b) Industrial Products
The following are the important industrial products produced through the process of fermentation.
B/otec
Products
Microorganisms used
Some uses
Formic acid
Aspergillus
Used in textile dyeing, leather treatment electroplating, rubber manufacture
Ethanol
Saccharomyces
Used as solvent; used in the production of vinegar and beverages
Glycerol
Saccharomyces
Used as solvent; used in the production of plastics, cosmetics and soaps; used in printing; used as sweetener
Acrylic acid
Bacillus
Used in the production of plastic