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Modelling the photosensitization‐based inactivation of Bacillus cereus
Author(s) -
Marc Y. Le,
Buchovec I.,
George S.M.,
Baranyi J.,
Luksiene Z.
Publication year - 2009
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2009.04275.x
Subject(s) - bacillus cereus , bacillales , microbiology and biotechnology , bacillaceae , bacillus (shape) , biology , chemistry , bacteria , food science , bacillus subtilis , genetics
Aims: To study and to develop a model for the photo‐destruction of the foodborne pathogen Bacillus cereus , initially treated with a precursor of endogenous photosensitizers (5‐aminolevulinic acid, ALA). Materials and methods: The cells were incubated in the presence of ALA (3 or 7·5 mmol l −1 ) for incubation times ranging from 2 to 60 min, inoculated onto the surface of LB Agar plates and submitted to light irradiation. The Weibull model was used to describe the survival curves of B. cereus . Quadratic equations were used to describe the effects of ALA concentration and incubation time on the Weibull model parameters. Results: ALA‐based photosensitization proved to be an effective tool for inactivation of B. cereus . The decrease in viable counts observed after 20 min of irradiation, ranged from 4 to 6 log CFU g −1 . Conclusions: The developed model proved to be a parsimonious and robust solution to describe the observed data. Significance and Impact of the Study: The study demonstrates the effectiveness of photosensitization on B. cereus on agar plates. The model developed may be useful to optimize inactivation treatments by photosensitization.