Effect of compressed carbon dioxide on microbial cell viability

• Published in: Applied and Environmental Microbiology Vol. 65; no. 2; pp. 626 - 631
• Main Authors: Debs-Louka, E, Louka, N, Abraham, G, Chabot, V, Allaf, K
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.02.1999
• Subjects: Action of physical and chemical agents on bacteria; Bacteriology; Biological and medical sciences; Carbon dioxide; Carbon Dioxide - pharmacology; Cells; Colony Count, Microbial; Decompression; Enterococcus faecalis; Enterococcus faecalis - drug effects; Enterococcus faecalis - growth & development; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - growth & development; food contamination; Food Microbiology; food processing; Fundamental and applied biological sciences. Psychology; Microbiological Techniques; Microbiology; Pressure; Saccharomyces cerevisiae; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - growth & development; Sterilization; Enterococcus faecalis; Yeast; Preservation; Escherichia coli; Carbon dioxide; Impact study; Inactivation; Pressure; Fungi; Streptococcaceae; Compressed air; Bacteria; Micrococcales; Ascomycetes; Exposure time; Biological contamination; Saccharomyces cerevisiae; Enterobacteriaceae; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.65.2.626-631.1999

In order to study the influence of compressed carbon dioxide, over a range of pressures (1.5 to 5.5 MPa) and exposure times (up to 7 h), on the survival of Escherichia coli, Saccharomyces cerevisiae, and Enterococcus faecalis, a new pressurizable reactor system was conceived. Microbial cells were inoculated onto a solid hydrophilic medium and treated at room temperature; their sensitivities to inactivation varied greatly. The CO2 treatment had an enhanced efficiency in cell destruction when the pressure and the duration of exposure were increased. The effects of these parameters on the loss of viability was also studied by response-surface methodology. This study showed that a linear correlation exists between microbial inactivation and CO2 pressure and exposure time, and in it models were proposed which were adequate to predict the experimental values. The end point acidity was measured for all the samples in order to understand the mechanism of microbial inactivation. The pHs of the treated samples did not vary, regardless of the experimental conditions. Other parameters, such as water content and pressure release time, were also investigated.