Question

name a useful bacterium​

Answer 1

Bacteria are useful and also harmful

The bacteria lactobacillus is useful for us.

it is used in making curd

Answer 2

Answer:

Lactobacillus Acidophilus

Dairy products like yogurt are prepared by exposing milk to lactobacillus acidophilus bacteria. The bacteria reside in our small intestine. Their presence in adequate amounts is very important as the body completely depends upon lactobacillus acidophilus for the manufacturing of vitamin K and other infection fighting agents. However, when the population of lactobacillus acidophilus decreases below the normal range, the person is likely to fall prey to various infections. Taking home-made yogurt on a daily basis is the best way to keep lactobacillus acidophilus population in the normal proportion.

⚡Hope it will help you.⚡