Tag: biotechnology

Plants and animals do not have the capacity to synthesize vitamin B12 by their own. But the microorganisms like Saccharomyces cerevisiae ( contains vitamin B12 but there is no clear answer about the source of synthesizing vitamin B12 in this yeast. But it synthesizes vitamin B12.), acetobacter and also by the mushrooms Agaricus. Thus, the correct answer is option D.

The curdling step in cheese making relies on lactic acid bacteria. These bacteria are able to ferment the carbohydrates found in the milk, releasing lactic acid in the process. The lactic acid causes the proteins dissolved in the milk to precipitate, or come out of solution. When the proteins precipitate, they pull out the fats as well. What you are left with is similar to the sour milk from the introduction: the liquid whey filled with many solid chunks of protein and fat, called curds.

The overall process of fermentation is to convert glucose sugar (C$ _6$H$ _{12}$O$ _6$) to alcohol (CH$ _3$CH$ _2$OH) and carbon dioxide gas (CO$ _2$). The reactions within the yeast to make this happen are very complex but the overall process is as follows: 

Chymosin, known also as rennin, is a proteolytic enzyme synthesized by chief cells in the stomach in young ruminants. Its role in digestion is to curdle or coagulate milk in the stomach, in the very young animal. Chymosin efficiently converts liquid milk to a semisolid like cottage cheese, allowing it to be retained for longer periods in the stomach. It is widely used in the production of cheese. 

Beer is an alcoholic beverage produced by the saccharification of starch and fermentation of the resulting sugar. The starch and saccharification enzymes are often derived from malted cereal grains, most commonly malted barley and malted wheat.

Lactobacillus bacteria have the ability to convert sugars into lactic acid. The Lactobacillus strain is so named because it was first studied in milk ferments. These bacteria readily use lactose or other sugars and convert them quickly and easily to lactic acid.

Aspergillus niger is a fungus and one of the most common species of the genus Aspergillus. Various strains of A. niger are used in the industrial preparation of citric acid and gluconic acid.

S. cerevisiae is known for its role in food production. It is the critical component in the fermentation process that converts sugar into ethyl alcohol (ethanol), an ingredient shared in beer, wine and distilled beverages. It is also used in the baking process as a leavening agent; yeast releasing gas into their environment results in the spongy-like texture of breads and cakes.