Bacteria, like the lactobacillus acidophilus use sugar as an energy source for anaerobic cellular respiration. this process produces much less atp than aerobic respiration and does not produce carbon dioxide as a by-product. it does, however, give yogurt its sour taste and prevents other food spoiling bacteria from developing.

Lactic acid fermentation

Explanation:

The lactic acid fermentation can be defined as the process by which sugar is being converted into lactic acid.

There is no emission of carbon dioxide during the whole process. In case of curd formation. The bacteria convert the milk into curd and provides it a sour taste.

It is converted by help of bacteria known as Lactobacillus acidophillus. This method is very frequently in many of food processing industry.