Microbial biotechnology is defined as any technological application that uses microbiological systems, microbial organisms or their derivatives, to manufacture or modify products or processes for specific use. Microbiology techniques are methods used for the study of microbes, including microscopic bacteria and fungi and protists. They include methods of study, culture, staining, identification, engineering and manipulation of microbes. They include bacteria, fungi, protozoa, microalgae and viruses. Microbes live in familiar environments such as the soil, water, food and intestines of animals, as well as in more extreme environments such as rocks, glaciers, hot springs and deep water vents. Microbial technology describes the production and uses of economical bacteria, yeasts, molds and viruses and reviews the technologies associated with microbial metabolism products.