Microorganisms are such life forms which cannot be seen by naked eye. But these microbes are said to be omnipotent with the nature that their existence is proved everywhere. They are present in soil, water, air, food, in animal intestines etc. and even their existence is proved with extreme conditions like within rocks, in glaciers, in hot springs and so on. Due to many selections and mutations made by environment towards microbes, led them to stay and survive with such extreme habitats and made them, the fittest of survival.