1.Micro organisms are helpful in making food stuffs.Example-yeast.
2.They are used in industries as a source of useful enzymes like lipases and proteases.
3.They are used in producing vaccines
4.They are used in cosmetics and oinments.
5.Rhizobium, a bacteria is useful in nitrogen fixation.
6.They are also helpful in producing vitamin B12
7.they produce amino acids used as a preservative.
8.Lactobacillus ,a bacteria helps in conversion of milk into curd.
9.They are used to flavour cheese.
10.They keep the soil fertile.