Nondestructive, reagent-free, low-volume fluidic set-up to study biofilms by using a transparent electrode, allowing simultaneous electrochemical and optical measurements

SAAVEDRA, ALBERT; MARTÍNEZ-CASILLAS, DIANA C; COLLET-LACOSTE, JEAN R; CORTÓN, EDUARDO

Journal of Applied Microbiology

Oxford Academics

Lugar: Oxford; Año: 2023 vol. 134 p. 1 - 9

AimsThe aim was to develop an electrochemical/optical set-up and correlate it (as validation) with other chemical and physical methods to obtain a simple and cost-effective system to study biofilm formation. Methods and ResultsA simple microfluidic cell and methods allowed continuous monitoring of the first, critical steps of microbial attachment. We monitored sulfate-reducing bacteria (SRB) at the early stages of biofilm formation. Herein, we studied the formation and adherence of SRB consortium biofilms over an indium tin oxide (ITO) conducting surface using microbiological and chemical methods, microscopic observations (SEM and optical), and electrochemical impedance (EIS) measurements. The SRB biofilm formation was evaluated for 30 days by SEM and EIS. Charge transfer resistance decreased when the microbial population colonized the electrode. The monitoring of early-stage biofilm formation was performed using EIS at a single frequency of 1 Hz during the first 36 hours. ConclusionsThe simultaneous use of optical, analytical, and microbiological methods allowed us to connect the kinetics of the growth of the microbial consortium to the values obtained via the electrochemical technique. The simple setup we present here can help laboratories with limited resources to study biofilm attachment and facilitates the development of various strategies to control biofilm development in order to avoid damage to metallic structures (microbiologically influenced corrosion, MIC) or the colonization of other industrial structures and medical devices. Significance and Impact of the StudyAs biofilm plays the main role in MIC and other important processes, which cause important economic losses, the set-up we present here can facilitate the design of biocide control programs to optimize dosage and periodicity in different industries, avoiding biofilm establishment.