Microbiology is a discipline of biology dealing with the microorganism which are not visible to the naked eye. This branch if biology also includes the mycology, virology, bacteriology, immunology, parasitology, and other branches dealing with the microorganisms. The classification of these organism is broad and diverse which includes the common ones such as the bacteria, virus, archaea, fungi, prions, protozoa, algae among others. They play a major role in climate changes, biodegradation, ecological niche, nutrient cycling, food degradation, diseases, food cycles, and other environmental factors. They are used in biotechnological purposes, biofuels, foods producing and processing, pollution drivers, diseases and control.