title: Biological indicators for steam sterilization: characterization of a rapid biological indicator utilizing Bacillus stearothermophilus spore-associated alpha-glucosidase enzyme.
abstract: The alpha-glucosidase enzyme was isolated from vegetative cells and spores of Bacillus stearothermophilus, ATCC 7953. Spore-associated enzyme had a molecular weight of approximately 92,700, a temperature optimum of 60 degrees C, and a pH optimum of 7.0-7.5. The enzyme in crude aqueous spore extract was stable for 30 min up to a temperature of 65 degrees C, above which the enzyme was rapidly denatured. The optimal pH for stability of the enzyme was approximately 7.2. The alpha-glucosidase in crude vegetative cell extract had similar characteristics to the spore-associated enzyme but its molecular weight was 86,700. The vegetative cell and spore-associated enzymes were cross-reactive. The enzymes are postulated to derive from a single gene product, which undergoes modification to produce the spore-associated form. The location of alpha-glucosidase in the spore coats (outside the spore protoplast) is consistent with the location of most enzymes involved in activation, germination and outgrowth.
authors.affiliation: School of Pharmacy and Pharmacology, University of Bath, UK.
authors.forename: H
authors.initials: H
authors.lastname: Albert
authors.forename: D J
authors.initials: DJ
authors.lastname: Davies
authors.forename: L P
authors.initials: LP
authors.lastname: Woodson
authors.forename: C J
authors.initials: CJ
authors.lastname: Soper
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D001411:Geobacillus stearothermophilus / Q000201:enzymology* / Q000502:physiology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008807:Mice, Inbred BALB C; D013171:Spores, Bacterial / Q000201:enzymology; D013227:Steam; D013242:Sterilization / Q000379:methods*; D013997:Time Factors; D000520:alpha-Glucosidases / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D015415:Biomarkers; D013227:Steam; D000520:alpha-Glucosidases