The examination of microscopic organisms inside of food is known as the Microbiological testing of food. These organisms may be with a single or multiple cells, or without a cell. Microbiology further includes several sub-disciplines such as Bacteriology, Mycology, Parasitology and Virology. Microorganisms play a vital role in our surrounding environment as all plants, animals, and humans consist of them. Moreover, they make up the principal mass of living components on earth.

These diversified and varied living organisms are able to grow even in extreme conditions, where no other living organism is able to survive. They can grow naturally in boiling point temperature, as well as inside of extreme freezing conditions such as -20 degrees or -30 degrees.

Microbial pathorgens, like Archaea and Bacteria, commonly known as prokaryotes and several types of protozoa, Fundi etc., which are known as eukaryotes must be taken care of well, as they can be harmful to an extent.