Efecto de la exposición a la luz ultravioleta uv-c en la viabilidad de especies de Eschericha coli y Salmonella typhimurium
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Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
Corporación Universitaria Lasallista
Facultad de Ingenierías
Facultad de Ingenierías
Abstract
Introduction. The germicidal effect UV-C
light has is regarded as an effective
tool to inactivate and eliminate harmful
contaminating agents, such as Escherichia
coli and Salmonella typhimurium. Objective.
evaluating the effectiveness of UV-C light for
reducing Escherichia coli and Salmonella
typhimorium populations from cultures
that had the microorganisms, combining
factors like concentration, time and
distance. Methodology. A UV-C lamp, with
a 254 nm and 8 volts power, was used;
the microbial strains used were Escherichia
coli and Salmonella typhimurium of ATCC
references. The factors to be measured
were the concentration of the microorganism
1x103 and 1x105 ufc/g, time 5-10 and
15 min, distance 5-10 and 20 cm. The
data were finally analyzed by the use of
descriptive statistics and variance analysis.
Results. a higher germicidal effect was
observed in the 1x105 concentration for
both microorganisms, thus demonstrating
significant differences of the microbial
reduction of Escherichia coli. The time with
the highest reduction of the growth rate
for both microorganisms was 15 minutes
and the distance with the highest microbial
reduction was 5cm. There were not,
nevertheless, significant differences of the
microbial reduction in the time and distance
factors. Besides, Salmonella typhimorium
had a higher sensibility to the exposition
than that of Escherichia coli. Conclusion.
the microbial concentration is a crucial
factor for the Escherichia coli`s survival.
After being exposed to the UV-C light,
Salmonella typhimorium is more sensible to
that exposition than Escherichia coli.
Description
Keywords
Corporación Universitaria Lasallista, Facultad de Ingenierías, Escherichia coli, Salmonella typhimurium, Luz ultravioleta uv-c, Desinfección