Tag: biotechnology and genetic engineering

Rennet is a complex of enzymes produced in stomachs of ruminant mammals which is used in the production of most cheeses. Chymosin, its key component, is a protease enzyme that curdles the casein in milk, helping young mammals digest their mothers' milk. It can also be used to separate milk into solid curds used for cheesemaking and liquid whey.

There are four principal methods available for immobilizing enzymes as follows:

Fermentation is an anaerobic process in which energy can be released from glucose even though oxygen is not available. Fermentation occurs in yeast cells. Yeasts are able to participate in fermentation because they have the necessary enzyme to convert pyruvic acid to ethyl alcohol. 

Large-scale, commercial production of citric acid is done by the microorganism, Aspergillus niger by aerobic fermentation of sucrose in beet molasses, a mould belonging to the same family as the penicillins.

Chlorellin, contained in chlorella, acts like a natural antibiotic. In contrast to chemical antibiotics, it combats pathogenic bacteria without altering the intestinal flora.

The most well known examples of yeast fermentation are in the production of alcoholic drinks and the leavening of bread. For their participation in these two processes, yeasts are of major importance in the food industry. Varieties of the Saccharomyces cervisiae genus are the most common yeasts in fermented foods and beverages. 

Streptomycin is an antibiotic that inhibits both gram-positive and gram-negative bacteria and is therefore a useful broad-spectrum antibiotic.

Brewer's yeast is often used as a source of B-complex vitamins, chromium, and selenium. The B-complex vitamins in brewer's yeast include B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B9 (folic acid), and H or B7 (biotin). These vitamins help break down carbohydrates, fats and proteins, which provide the body with energy. They also support the nervous system, help maintain the muscles used for digestion, and keep skin, hair, eyes, mouth, and liver healthy.

Rennin, also called as chymosin, protein-digesting enzyme that curdles milk by transforming caseinogen into insoluble casein; it is found only in the fourth stomach of cud-chewing animals, such as cows. Its action extends the period in which milk is retained in the stomach of the young animal. In animals that lack rennin, milk is coagulated by the action of pepsin, as is the case in humans. A commercial form of rennin, rennet, is used in manufacturing cheese and preparing junket.

Secondary metabolites, including antibiotics, are produced in nature and serve survival functions for the organisms producing them. Secondary metabolites serve: (i) as competitive weapons used against other bacteria, fungi, amoebae, plants, insects, and large animals; (ii) as metal transporting agents; (iii) as agents of symbiosis between microbes and plants, nematodes, insects, and higher animals; (iv) as sexual hormones; and (v) as differentiation effectors. Although antibiotics are not obligatory for sporulation, some secondary metabolites (including antibiotics) stimulate spore formation and inhibit or stimulate germination.