Adhesion and removal kinetics of Bacillus cereus biofilms on Ni-PTFE modified stainless steel

Abstract

Biofilm control remains a challenge to food safety. A well-studied non-fouling coating involves codeposition of polytetrafluoroethylene (PTFE) during electroless plating. This coating has been reported to reduce foulant build-up during pasteurization, but opportunities remain in demonstrating its efficacy in inhibiting biofilm formation. Herein, the initial adhesion, biofilm formation, and removal kinetics of Bacillus cereus on Ni-PTFE-modified stainless steel (SS) are characterized. Coatings lowered the surface energy of SS and reduced biofilm formation by > 2 log CFU cm⁻². Characterization of the kinetics of biofilm removal during cleaning demonstrated improved cleanability on the Ni-PTFE coated steel. There was no evidence of biofilm after cleaning by either solution on the Ni-PTFE coated steel, whereas more than 3 log and 1 log CFU cm⁻² of bacteria remained on the native steel after cleaning with water and an alkaline cleaner, respectively. This work demonstrates the potential application of Ni-PTFE non-fouling coatings on SS to improve food safety by reducing biofilm formation and improving the cleaning efficiency of food processing equipment.

Keywords:

• Nickel polytetrafluoroethylene (Ni-PTFE)
• non-fouling stainless steel
• biofilm
• Bacillus cereus
• fouling release coatings
• biofouling

Acknowledgements

The authors gratefully acknowledge Dr Julian McClements for use of a Kruss DSA100.