Which of the following is correct about microorganisms?
i. Microorganisms are used as food preservatives.
(ii), (iii) and (iv)
Some bacteria are able to fix atmospheric nitrogen in the soil to increase the fertility of soil. The microorganisms can decompose dead organic waste of plants and animals converting them into simple substances. Penicillin is an antibiotic which kills or stops growth of the disease causing microorganisms. Antibiotics are produced from bacteria and fungi.