The ARS Culture Collection (NRRL) - Our Facilities
- The collection is housed within the Mycotoxin Prevention and Applied Microbiology Research Unit at the National Center for Agricultural Utilization Research in Peoria, Illinois.
Where we are...
- The first large-scale use of lyophilization for culture preservation was pioneered at NCAUR by Wickerham for yeasts and by Raper for aspergilli and penicillia. The process consists of freezing microorganisms within small glass ampules in an appropriate liquid suspending medium such as bovine serum and applying a vacuum to sublime the water from the frozen preparations. Following drying, the ampules are sealed under vacuum with a gas-oxygen torch and then stored at 5ºC.
Preservation - Lyophilization
- Some microorganisms, such as asporogenous filamentous fungi and certain yeasts and bacteria, do not survive the lyophilization process. These strains are maintained as frozen stocks in liquid nitrogen. Liquid nitrogen storage seems to cause little or no genetic change in cells. The reasons for not relying on this method exclusively for preservation of cultures are: cost and the fact that lyophilized preparations may be shipped by regular mail whereas strains preserved by liquid nitrogen must first be grown on agar or in liquid medium to avoid the expense of shipping frozen materials.