Monitoring Aerobic Marine Bacterial Biofilms on Gold Electrode Surfaces and the Influence of Nitric Oxide Attachment Control

Detection of aerobic marine bacterial biofilms using electrochemical impedance spectroscopy has been done to monitor the interfacial response of Pseudoalteromonas sp. NCIMB 2021 attachment and growth in order to identify characteristic events on a 0.2 mm diameter gold electrode surface. Uniquely, the applicability of surface charge density has been proven to be valuable in determining biofilm attachment and cell enumeration over a 72 h duration on a gold surface within a modified continuous culture flow cell (a controlled low laminar flow regime with Reynolds number asymptotic to 1). In addition, biofilm dispersal has been evaluated using 500 nM sodium nitroprusside, a nitric oxide donor (nitric oxide is important for the regulation of several diverse biological processes). Ex situ confocal microscopy studies have been performed to confirm biofilm coverage and morphology, plus the determination and quantification of the nitric oxide biofilm dispersal effects. Overall, the capability of the sensor to electrochemically detect the presence of initial bacterial biofilm formation and extent has been established and shown to have potential for real-time biofilm monitoring.

Automated summary

This study used electrochemical impedance spectroscopy to monitor the formation and dispersal of aerobic marine bacterial biofilms, successfully identifying characteristic events on a gold electrode surface and proving the applicability of surface charge density in biofilm attachment and cell enumeration. Through ex situ confocal microscopy studies, the morphology of biofilms and the effects of nitric oxide on biofilm dispersal were further determined and quantified.