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Heindl,P.; Fernández García,A.; Büttner,M.; Voigt,H.; Butz,P.; Tauscher,B.; Pfaff,E.. |
Crude brain homogenates of terminally diseased hamsters infected with the 263 K strain of scrapie (PrP Sc) were heated and/or pressurized at 800 MPa at 60ºC for different times (a few seconds or 5, 30, 120 min) in phosphate-buffered saline (PBS) of different pH and concentration. Prion proteins were analyzed on immunoblots for their proteinase K (PK) resistance, and in hamster bioassays for their infectivity. Samples pressurized under initially neutral conditions and containing native PrP Sc were negative on immunoblots after PK treatment, and a 6-7 log reduction of infectious units per gram was found when the samples were pressurized in PBS of pH 7.4 for 2 h. A pressure-induced change in the protein conformation of native PrP Sc may lead to less PK... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Native prion protein; Pressure; Inactivation; PH; Proteinase K sensitivity; Prion conformation. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000800010 |
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Yamamoto,K.; Matsubara,M.; Kawasaki,S.; Bari,M.L.; Kawamoto,S.. |
Escherichia coli, as a model microorganism, was treated in phosphate-buffered saline under high hydrostatic pressure between 100 and 300 MPa, and the inactivation dynamics was investigated from the viewpoint of predictive microbiology. Inactivation data were curve fitted by typical predictive models: logistic, Gompertz and Weibull functions. Weibull function described the inactivation curve the best. Two parameters of Weibull function were calculated for each holding pressure and their dependence on holding pressure was obtained by interpolation. With the interpolated parameters, inactivation curves were simulated and compared with the experimental data sets. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Predictive microbiology; Pressure; Escherichia coli; Inactivation; Model. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000800014 |
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Elmnasser, Noura; Ritz, Magali; Leroi, Francoise; Orange, Nicole; Bakhrouf, Amina; Federighi, Michel. |
Pulsed light is a new method intended for the decontamination of food surfaces using short, high frequency pulses of an intense broad spectrum. The effects of broad spectrum pulsed light on the survival of Listeria monocytogenes Scott A, Listeria monocytogenes CNL, Pseudomonas fluorescens MF37 and Photobacterium phosphoreum SF680 populations on agar and in a liquid medium were investigated during this study. The sterilisation system generated 1.5 J cm(-2) per pulse with eight lamps for 300 mu s. In the case of surface-seeded cells, a 7.8, 8.14 and > 7.14 log reduction was obtained for L. monocytogenes, Ps. fluorescens MF37 and Ph. phosphoreum, respectively, after a single pulse of treatment. Inactivation levels were lower for depth-plated cells: indeed,... |
Tipo: Text |
Palavras-chave: Efficiency; Inactivation; Bacteria; Treatment; Pulsed light. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3041.pdf |
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