Microorganisms in Food Production

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.

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.

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. 

S. cerevisiae is known for its role in food production. It is the critical component in the fermentation process that converts sugar into alcohol, an ingredient shared in beer, wine, and distilled beverages. It is also used in the baking process as a leavening agent.

Zymase, an enzyme from yeast, changes the simple sugars into ethanol and carbon dioxide.

Yoghurt is produced through the fermentation of milk by lactic acid bacteria, usually Lactobacillus bulgarius and Streptococcus thermophilus. Acetobacter aceti bacteria are a widespread group of gram-negative, obligate aerobic rods which oxidize ethanol (alcohol) into ethanoic (acetic) acid.

Alcohol fermentation is done by yeast and some kinds of bacteria. These microorganisms convert sugars into ethyl alcohol and carbon dioxide.

Penicillium roqueforti is a common saprotrophic fungus. The major industrial use of this fungus is the production of blue cheese, flavouring agents, antifungals, polysaccharides, proteases and other enzymes. The fungus has been a constituent of roquefort, stilton, Danish blue, cabrales and other blue cheese.

Baker's yeast is the common name for the strains of yeast commonly used as a leavening agent in baking bread and bakery products, where it converts the fermentable sugars present in the dough into carbon dioxide and ethanol. Baker's yeast is of the species Saccharomyces cerevisiae.

Sugarcane (Saccharum or Hidnarum) is the main source of commercial ethyl alcohol. Source is extracted from the juice of sugarcane as a commercial product, but this leaves a syrup called molasses which contains glucose and fructose. Ethanol is produced by the fermentation of molasses by using yeast Saccharomyces cerevisiae.

Fermenting agents are Saccharomyces cerevisiae, S.sake, S.ellipsoidens. Molasses and fruit juice are more commonly used in brewing industry. Molasses is a dark coloured syrup left after the extraction of sugar. Yeasts are used as supplement to human food, Brewer's yeast is a readily available source of protein. At present the scientists are thinking of microscopic forms of food  (fungi as a single cell protein) or atleast as food flavouring agent

In stirred tank bioreactors, the oxygen mass transfer is a function of many variables, such as the physical properties of the liquid (viscosity, surface tension, etc.), the geometry of the vessel and stirrer and the operational conditions. In the stirred-tank bioreactor, the stirrer facilitates even mixing and oxygen availability throughout the bioreactor. 

Red yeast is used for maintaining desirable cholesterol levels in healthy people. The active ingredient in red yeast is the same as the active ingredient in prescription drugs called statins used for high cholesterol. Thats why, red yeast has all the possible side effects, drug interactions, and precautions associated with this type of drug.

The bacterium Clostridium acetylbutylicum, easliy converts any fermentable sugar to butanol and additionally produces hydrogen gas, acetone, isopropyl alcohol. Isopropanol is a product of the organism formerly known as Clostridium butylicum, which is now included in the species Clostridium beijerinckii.