Journal
LWT-FOOD SCIENCE AND TECHNOLOGY
Volume 44, Issue 1, Pages 191-198Publisher
ELSEVIER
DOI: 10.1016/j.lwt.2010.05.012
Keywords
UV-C light; Inactivation; Flow cytometry; E. coli; S. cerevisiae; L. innocua
Categories
Funding
- Universidad de Buenos Aires
- Universidad Nacional de Lujan
- CONICET
- ANPCyT of Argentina
- BID
Ask authors/readers for more resources
Flow cytometry (FCM) is a powerful tool for analyzing physiological characteristics of microorganisms on a single-cell basis and identifying heterogeneities within population. This work analyzed the UV-C induced damage on Escherichia coli ATCC 11229; Listeria innocua ATCC 33090 and Saccharomyces cerevisiae KE162 cells by applying flow cytometry technique. The UV-C doses, obtained by altering the exposure time and measured by the iodide-iodate chemical actinometer, ranged between 0 and 5 kJ/m(2). E. coli; L. innocua and S. cerevisiae populations were quantified by plate count technique. For flow cytometry studies, cells were labeled with fluorescein diacetate (FDA) for detecting membrane integrity and esterase activity, and with propidium iodide (PI) for monitoring membrane integrity. The results showed that mechanisms of cellular damage differed according to time of exposure to ultraviolet radiation and the organism tested. E. coli and S. cerevisiae sub-populations with PI increased within the first minutes of UV-C treatment, without much change afterwards. On the contrary, FCM was used to detect the inactivation of those L innocua sub-populations of viable microorganisms (maintaining metabolic activity) which were non-culturable due to membrane rupture and thus not detectable by viable plate count technique. (C) 2010 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available