In general bacteria tend to accumulate at interfaces between two phases in heterogeneous systems. As long as water is available for microbial growth, microorganisms can be found foods and processing environments at solids-liquid, gas-liquid, and solid-gas interfaces. In their natural environments, bacteria do not exist as isolated cells but grow and survive in organized communities on surfaces. These communities are called biofilms and can be simplistically defined as bacterial growth on a solid surface. When growing in a biofilm, bacteria are known to have different growth rate, morphology, and physiology than their planktonic counterparts and may exhibit varied physiological responses to nutrient conditions resulting in increased resistance to antimicrobials agents compared with their planktonic forms.
Multispecies biofilms within food processing environments are a major source of L. monocytogenes in processed foods. When growing on surfaces, this organism exhibits enhanced resistance to conventional chemical sanitizers, germicides and heat making control even more challenging.
My laboratory is interested in multiple aspects of biofilms:
- The genetics of Listeriasp. biofilm growth.
- The biological, physical and chemical aspects of bacterial adhesion, transfer and removal.
- Antimicrobial delivery systems for cleaning and sanitation