Welcome to the ARS Culture Collection (also known as the NRRL Collection) website. The Collection is one of the largest public collections of microorganisms in the world, currently containing approximately 95,000 strains of actinomycetes, bacteria, molds, and yeasts. The collection is housed within the Microbial Genomics and Bioprocessing Research Unit at the National Center for Agricultural Utilization Research in Peoria, Illinois.

This site provides information regarding the public ("open") collection of strains, which includes a searchable public access catalog for many of the holdings of well characterized strains. The site also provides information on the deposit and distribution of strains maintained in the ARS Patent Culture Collection, which is historically the first collection for strains related to patent applications in the world. The holdings of the patent strains, except for those that also serve as type strains, are not searchable, but the website provides the protocol for obtaining patent strains that are released to the scientific public.

A number of important endangered collections, including the Howard Dulmage collection of insecticidal Bacillus strains, the International Streptomyces Project (ISP) collection and the Jack Fell collection of marine yeasts, have been accessioned into the ARS Culture Collection and may be found in the online catalog. Several other endangered collections, such as the U. S. Army Quartermaster Collection of Fungi and the University of Wyoming Soil Fungi Collection, are held here for safe-keeping but are not accessioned into the ARS Culture Collection.