Effects of freezing on the survival of Escherichia coli and Bacillus and response to UV and chlorine after freezing

Escherichia coli (E. coli) and Bacillus megaterium bacteria were frozen at -15 degrees C using a freezer and a spray freezing method. The frozen Bacillus spores were also exposed to UV and free chlorine. An average of 4.7-log inactivation was obtained from the spray ice with 2-day storage time, whil...

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Détails bibliographiques
Publié dans:Water environment research : a research publication of the Water Environment Federation. - 1998. - 79(2007), 5 vom: 09. Mai, Seite 507-13
Auteur principal: Gao, W (Auteur)
Autres auteurs: Smith, D W, Li, Y
Format: Article
Langue:English
Publié: 2007
Accès à la collection:Water environment research : a research publication of the Water Environment Federation
Sujets:Evaluation Study Journal Article Research Support, Non-U.S. Gov't Chlorine 4R7X1O2820
Description
Résumé:Escherichia coli (E. coli) and Bacillus megaterium bacteria were frozen at -15 degrees C using a freezer and a spray freezing method. The frozen Bacillus spores were also exposed to UV and free chlorine. An average of 4.7-log inactivation was obtained from the spray ice with 2-day storage time, while the freezer freezing only caused 0.84-log reduction with the same storage time. Significantly higher inactivation levels were observed for the E. coli cells with 2-day storage compared with those without storage. The spray freezing was found more effective in killing the E. coli cells, while more cells were sublethally injured by the freezer freezing. Freezing did not kill the Bacillus megaterium spores, but affected their response to UV and chlorine. Greater inactivation levels were observed at higher free chlorine doses or longer contact time, and the UV fluence-response curve showed initial rapid kill followed by tailing for the frozen spores
Description:Date Completed 02.08.2007
Date Revised 10.12.2019
published: Print
Citation Status MEDLINE
ISSN:1554-7531