69432 20181017144516.0 doi 10.1128/AEM.00623-13 sideral 82653 ART-2013-82653 eng (orcid)0000-0002-5895-2157 Gayán, E. Universidad de Zaragoza Mechanism of the synergistic inactivation of Escherichia coli by UV-C light at mild temperatures 2013 Access copy available to the general public Unrestricted UV light only penetrates liquid food surfaces to a very short depth, thereby limiting its industrial application in food pasteurization. One promising alternative is the combination of UV light with mild heat (UV-H), which has been demonstrated to produce a synergistic bactericidal effect. The aim of this article is to elucidate the mechanism of synergistic cellular inactivation resulting from the simultaneous application of UV light and heat. The lethality of UV-H treatments remained constant below ~45ºC, while lethality increased exponentially as the temperature increased. The percentage of synergism reached a maximum (40.3%) at 55ºC. Neither the flow regimen nor changes in the dose delivered by UV lamps contributed to the observed synergism. UV-H inactivation curves of the parental Escherichia coli strain obtained in a caffeic acid selective recovery medium followed a similar profile to those obtained with uvrA mutant cells in a nonselective medium. Thermal fluidification of membranes and synergistic lethal effects started around 40 to 45ºC. Chemical membrane fluidification with benzyl alcohol decreased the UV resistance of the parental strain but not that of the uvrA mutant. These results suggest that the synergistic lethal effect of UV-H treatments is due to the inhibition of DNA excision repair resulting from the membrane fluidification caused by simultaneous heating. info:eu-repo/grantAgreement/ES/CICYT-FEDER/CIT-020000-2009-40 info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 3.952 2013 MICROBIOLOGY 24 / 119 = 0.202 2013 Q1 T1 BIOTECHNOLOGY & APPLIED MICROBIOLOGY 30 / 165 = 0.182 2013 Q1 T1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion (orcid)0000-0002-7971-4828 Mañas, P. Universidad de Zaragoza (orcid)0000-0003-2430-858X Álvarez, I. Universidad de Zaragoza (orcid)0000-0002-1902-0648 Condón, S. Universidad de Zaragoza 2008 780 Universidad de Zaragoza Dpto. Produc.Animal Cienc.Ali. Área Tecnología de Alimentos 79, 14 (2013), 4465-4473 Appl. environ. microbiol. APPLIED AND ENVIRONMENTAL MICROBIOLOGY 0099-2240 264173 http://zaguan.unizar.es/record/69432/files/texto_completo.pdf Versión publicada 138581 http://zaguan.unizar.es/record/69432/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:69432 articulos driver 2018-10-17-14:44:06 ARTICLE