Grant: Discovery Grants Program - Individual

Naturally occurring bacteria protect themselves by the formation of a sugary layer called a biofilm which allows them to resist to traditional cleansing techniques. Cleansing equipment ""fouled"" with biofilms is a major cost in many industries such as pulp and paper production, food processing and soil remediation. The ability of supercritical carbon dioxide (SC-CO2) to kill bacteria is documented but not well understood. Supercritical carbon dioxide is simply carbon dioxide (present in our breath and making up about 0.04% of the atmosphere) at pressures higher than 73 atmospheres and temperatures higher than 31 Celsius. Supercritcal carbon dioxide has properties that are useful to sterilization. The gas-like properties of SC-CO2 allow it to readily penetrate to the bacteria. Its liquid-like properties allow a much higher concentration of carbon dioxide to reach the bacteria compared to the gas. This project will explore how SC-CO2 kills bacteria using advanced theoretical techniques combined with computer simulation and determine if SC-CO2's antimicrobial capability can be further enhanced with small amounts of specially selected bactericidal molecules. Two types of additive will be studied: 1) short bactericidal proteins and 2) antioxidants. Because little or no theoretical modelling of bacterial membranes in SC-CO2 has been done, this research program is likely to yield novel results that may have a positive economic impact on industries affected by bacterial biofilm ""fouling"".