Answer:
Soil
Step-by-step explanation:
There are many different types of bacteria found in soil that has antimicrobial activity in it.
The soil has many different varieties of bacteria and microorganisms that are capable of producing antibiotic.
These bacteria are extracted from the soil and antibiotic production is done in order to treat many disease.
Long time ago, people used to put soil on the wounds as it has antimicrobial activity which treats infection.