Which gas is released during the process of fermentation that gives the puffy appearance to dough for making bread?

Which of the following statements does $NOT$ represent the importance of $LAB$?

What is the role of microbes in the production of cheese?

The process of heating milk to $62.8^{\circ}C$ for $30$ minutes followed by cooling is known as ..........

Statement $P$: $LAB$ is used to make bread.
Statement $Q$: $Lactobacillus$ is used to make curd.

Statement $X$: $LAB$ (Lactic Acid Bacteria) is very useful for the digestive system.
Statement $Y$: $LAB$ protects us from harmful bacteria in the stomach.