Microbiology is the study of microorganisms, a large and diverse group of organisms that exist as single cells or cell clusters. It is a broad biological discipline which includes basic research as well as applied science. The identification of microorganisms is part of medical microbiology as well as quality testing e.g. in pharmaceutical and food industry. Examples for the usage of microbes in industrial processes include fermentation (e.g. production of food & beverages, drugs, vaccines, biofuels, enzymes) and waste-water treatment.