 Microorganisms are used to prepare bioactive molecules such as Streptokinase from the bacterium "Streptococcus", Cyclosporin A from the ascomycete fungus "Tolypocladium inflatum", and statins produced by the yeast "Monascus purpureus".Microorganisms are essential tools in biotechnology, biochemistry, genetics, and molecular biology.The yeasts "Saccharomyces cerevisiae" and "Schizosaccharomyces pombe" are important model organisms in science, since they are simple eukaryotes that can be grown rapidly in large numbers and are easily manipulated.