Electrochemical Sensing for Aerobic Marine Bacterial Biofilms within Seawater Piping Systems

摘要

The ability to detect aerobic bacterial biofilms within marine seawater piping systems, where metallic surfaces are directly exposed to fouling, is often limited by a lack of suitable techniques capable of sensing for the presence of a biofilm. Consequently, this has led to ineffective and inefficient biofilm inhibition strategies (biocide dosing) which can frequently result in the loss of platform performance. An attractive alternative to the present biofilm control strategies based on biocides would be to sense, quantitatively evaluate and then induce biofilm disruption (using a natural biocide) when necessary. The presence of a biofilm is known to modify the electrochemical properties of a metal / electrolyte interface, as well as the physical effects such as thermal diffusion or mass transport of surface active species. To investigate bacterial biofilm formation and development, electrochemical impedance spectroscopy was performed under laboratory culture conditions (modified continuous culture flow cell) using artificial seawater with a single Pseudoalteromonas sp. strain NCIMB 2021 during a 72 h immersion. This system uniquely studied the initial bacterial adhesive interactions with metallic surfaces under a controlled flow cell environment. Fluorescence microscopy has also been used to corroborate the performance of the bacterial biofilms sensing approach. Overall, the capability of the electrochemical sensor to detect the presence of initial bacterial biofilm formation and development will be presented. Key parameters of the sensing response will be proposed as biofouling indicators, thus allowing a more effective and efficient dosing strategy.