title: A microwave-powered sterilizable interface for aseptic access to bioreactors that are vulnerable to microbial contamination.
abstract: Novel methods and apparatus that employ the rapid heating characteristics of microwave irradiation to facilitate the aseptic transfer of nutrients, products, and other materials between microbially sensitive systems and the external environment are described. The microwave-sterilizable access port (MSAP) consists of a 600-W magnetron emitting at a frequency of 2.45 GHz, a sterilization chamber with inlet and outlet flow lines, and a specimen transfer interface. Energy is routed to the sterilization chamber via a coaxial transmission line where small quantities of water couple strongly with the incident radiation to produce a superheated vapor phase. The efficiency of energy transfer is enhanced through the use of microwave susceptors within the sterilization chamber. Mating surfaces are thermally sterilized through direct contact with the hot gas. Efficacy has been demonstrated using the thermophile Bacillus stearothermophilus.
authors.affiliation: UMPQUA Research Company, P.O. Box 609, Myrtle Creek, Oregon 97457, USA. jatwater@urcmail.net
authors.forename: J E
authors.initials: JE
authors.lastname: Atwater
authors.forename: W F
authors.initials: WF
authors.lastname: Michalek
authors.forename: R R
authors.initials: RR
authors.lastname: Wheeler
authors.forename: R
authors.initials: R
authors.lastname: Dahl
authors.forename: T D
authors.initials: TD
authors.lastname: Lunsford
authors.forename: F C
authors.initials: FC
authors.lastname: Garmon
authors.forename: R L
authors.initials: RL
authors.lastname: Sauer
mesh_terms: D019149:Bioreactors / Q000382:microbiology / Q000592:standards*; D004866:Equipment Contamination / Q000517:prevention & control*; D001411:Geobacillus stearothermophilus / Q000472:pathogenicity; D008872:Microwaves; D013227:Steam; D013242:Sterilization / Q000295:instrumentation / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D013227:Steam