Microorganisms in Food Production - Class VIII

Yeast is a single-celled, microscopic fungus which uses sugar as food. Ethanol fermentation is a biological process of converting sugars to alcohol and carbon dioxide. It is performed by yeasts in the absence of oxygen. 

Yeast is used in baking because it reproduces rapidly and performs fermentation, which releases carbon dioxide gas. This gas gets trapped in the dough, causing it to rise.

Yeast reproduces rapidly and produces carbon dioxide during respiration. Bubbles of the gas fill the dough and increase its volume.

Fermentation is the process which is carried by anaerobic respiration of microorganism which leads to the production of lactic acid or alcohol with the release of carbon dioxide. When the yeast is added to the dough of the bread it converts the sugar to ethanol and carbon dioxide which forms bubbles. Yeast has a lot of economical value to the mankind. It is used in the production of bread, wine, curd etc.

Streptococcus lactis is an important bacteria responsible for manufacturing of  dairy product, curd. It converts milk into curd by the process of fermentation. It breaks the sugar present in the milk and produces lactic acid. This lactic acid results in the curdling of the milk proteins and produces curd with a tangy taste.

• In the production of bread one of the step is fermentation which is done with the help of the yeast or better know as baker's yeast ie Saccharomyces cerevisiae 
• At the time of making dough for the bread yeast is added along with other ingredients and is left to rest for sometime which gives yeast time for the fermentation process where it converts the sugar present in the  flour to carbon dioxide and alcohol.
• When the dough is baked the release of carbon dioxide at the time of baking leaves holes in the bread which gives the bread its sponginess
• So, the correct answer is 'Evolution of CO22 makes the bread spongy'
  

• Saccharomyces cerevisiae also know as Baker's yeast is used in bread making and in production of many other bakery products.
• It is used for the act of fermentation which is done by the yeast on the sugar/starch that is present in the flour. The starch is converted into alcohol and carbon dioxide by the act of fermentation.
• The carbon dioxide in the dough makes the bread dough to rise and also provides the bread with softness and makes it fluffy after it is cooked.
• So, the correct answer is 'Saccharomyces cerevisiae'
  

Yeast is a fungal species that converts carbohydrates to carbon dioxide and alcohols. Saccharomyces cerevisiae is responsible for the production of ethyl alcohol.

The yeast most commonly used for leavening bread is Saccharomyces cerevisiae, the same species used for brewing alcoholic beverages. This yeast ferments some of the carbohydrates in the flour, including any sugar, producing carbon dioxide. 

Bread is prepared from the dough, which is fermented using baker's yeast ( Saccharomyces cerevisiae ). The puffed-up appearance of dough is due to the production of carbon dioxide during fermentation. Carbon dioxide gas along with ethyl alcohol evaporate during baking, making bread porous and soft. 

Saccharomyces cerevisiae, commonly known as baker's yeast, is the primary microorganism used in the bread-making process for leavening.

In the making of bread both carbon dioxide and alcohol are trapped by the dough and both are expelled from the dough by the heat of baking. So, the bread tastes semi-sweet.

• Yeast is used as a leavening agent in bread making. Yeast converts sugars present in the dough to carbon dioxide.