title: The effect of bioindicator preparation and storage on thermal resistance of Bacillus stearothermophilus spores.
abstract: Paper strips inoculated with spores of Bacillus stearothermophilus ATCC 7953 were conventionally dried (lot 1) and lyophilized (lot 2); stored in defined environments of 32 and 86% relative humidity at 10, 25 and 33 degrees C for 210 d; and submitted to moist heat treatments at 121 degrees C. A significant decrease in thermal resistance from initial starting levels was found for lyophilized bioindicators stored at 86% relative humidity. The respective average D121 degrees C values were 1.55+/-0.05 and 1.37+/-0.10 min for lyophilized bioindicators stored at 32 and 86% relative humidity; and 1.65+/-0.15 min and 1.57+/-0.11 min for dried bioindicators stored in the same environments.
authors.affiliation: Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Science, University of São Paulo, Brazil. tcvpenna@usp.br
authors.forename: Thereza Christina Vessoni
authors.initials: TC
authors.lastname: Penna
authors.forename: Marina
authors.initials: M
authors.lastname: Ishii
authors.forename: Irene Alexeevna
authors.initials: IA
authors.lastname: Machoshvili
authors.forename: Marcelo
authors.initials: M
authors.lastname: Marques
mesh_terms: D000704:Analysis of Variance; D001431:Bacteriological Techniques / Q000379:methods; D001411:Geobacillus stearothermophilus / Q000254:growth & development / Q000502:physiology*; D006358:Hot Temperature; D012044:Regression Analysis; D013171:Spores, Bacterial