Which bacteria are responsible for converting milk into curd?

$LAB$ (Lactic Acid Bacteria) are used to curdle milk by producing:

Which yeast is used for making bread?

During the production of bread,the release of $CO_2$ by the action of which organism makes it porous?

Which of the following are the main benefits of $LAB$?
$I.$ Increase vitamin-$B_{12}$ amount,thus increasing nutrient quality of milk.
$II.$ Checks disease-causing microbes in the stomach.
Choose the correct option.

The microorganism that converts milk into curd is ..........