Bacillus amyloliquefaciens is a species of bacterium in the genus Bacillus that is the source of the BamH1 restriction enzyme. It also synthesizes a natural antibiotic protein barnase, a widely studied ribonuclease that forms a famously tight complex with its intracellular inhibitor barstar, and plantazolicin, an antibiotic with selective activity against Bacillus anthracis.[1] B. amyloliquefaciens was discovered in soil 1943 by a Japanese scientist named Fukumoto,[2] who gave the bacterium its name because it produced (faciens) a liquifying (lique) amylase (amylo). Alpha amylase from B. amyloliquefaciens is often used in starch hydrolysis. It is also a source of subtilisin, which catalyzes the breakdown of proteins in a similar way to trypsin. Between the 1940s and the 1980s, bacteriologists debated as to whether or not B. amyloliquefaciens was a separate species or a subspecies of Bacillus subtilis. The matter was settled in 1987 established it as a separate species.[3] In the American Type Culture Collection, the number for B. amyloliquefaciens is 23350.