| | Maso, 6/2011 str.8-11
Brychta Tomáš, Brychta Josef, Steinhauserová Iva, Klímová Eva,
Summary
This study has been aimed at two experiments.
First experiment was the observation of the bactericidal effect of UV light (254 nm) on bacterial populations of Listeria monocytogenes (mixture of 3 most common serotypes) and Escherichia coli (mixture of two different isolates) with exposition from 1 – 20 minutes. Test was performed on Petri dishes (ALOA and PALCAM for Listeria and ENDO agar for Escherichia) with concentration of bacterial contamination of 100 CFU/cm2. It was shown that even 1 minute exposition to UV light is enough to inactivate both bacteria on smooth surface of Petri dish.
Second experiment was aimed at possible reduction of bactericidal effect of UV light
(254 nm) on bacterial populations of Listeria monocytogenes (mixture of 3 most common serotypes) and Escherichia coli (mixture of two different isolates) by shadow created by crumbs, fluff and pin placed directly onto Petri dish and by paperclip and polyetylen bag put above Petri dish. We discovered that crumbs and pin placed directly onto Petri dish created shadow enough to block the inactivation. No blocking of inactivation was discovered in case of paperclip, polyetylen bag and fluff.
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