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The development of Escherichia coli and Listeria monocytogenes variants resistant to high‐pressure carbon dioxide inactivation
Author(s) -
GarciaGonzalez L.,
Rajkovic A.,
Geeraerd A.H.,
Elst K.,
Van Ginneken L.,
Van Impe J.F.,
Devlieghere F.
Publication year - 2010
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2010.02839.x
Subject(s) - listeria monocytogenes , escherichia coli , microbiology and biotechnology , biology , carbon dioxide , bacteria , food science , gene , biochemistry , ecology , genetics
Abstract Aims: The objective of this study was to investigate whether bacterial cells could develop resistance (as a part of their adaptation strategy) to high‐pressure CO 2 (HPCD) inactivation. Methods and Results: Alternating cycles of exposure to pressurized CO 2 (10·5 MPa, 35°C, 400 min −1 , 70% working volume ratio during 10 min) and re‐growth of the surviving subpopulation were used to investigate possible increases in the resistance of Escherichia coli and Listeria monocytogenes to HPCD. The results show an increased resistance of both pathogens tested after seven cycles of inactivation. Increase in the resistance after 15 cycles resulted in a difference of 2·4 log CFU ml −1 in log N 0 /N i when parental (N 0 ) and treated cultures (N i ) of E. coli and L. monocytogenes were compared. Conclusions: Current findings indicate the ability of micro‐organisms to adapt to HPCD preservation technology. Significance and Impact of the Study: The occurrence of HPCD‐resistant micro‐organisms could pose a new hazard to the safety and stability of HPCD‐processed foods.