Activation of Protein Expression in Electroactive Biofilms

Area of Science:

• Bioelectrochemistry
• Microbial Physiology
• Biosensing

Background:

• Microbial biofilms on electrodes can be engineered into electronic devices for sensing and computation.
• Real-time visualization of biofilm formation and protein expression alongside electrochemical measurements is challenging with conventional systems.

Purpose of the Study:

• To develop a novel electrochemical flow cell for simultaneous in situ electrochemistry and fluorescence imaging of electrically active biofilms.
• To assess the performance of *Marinobacter atlanticus* biofilms as living electronic sensors.

Main Methods:

• Fabrication of a 3D-printed flow cell integrating electrochemical and fluorescence imaging capabilities.
• Cultivation of *Marinobacter atlanticus* biofilms expressing green fluorescent protein (GFP) on the working electrode.
• Utilized an isopropyl β-d-1-thiogalactopyranoside (IPTG) inducible system to monitor yellow fluorescent protein (YFP) expression dynamics.

Main Results:

• Demonstrated correlation between increasing electrical current and biofilm surface coverage.
• Successfully visualized spatiotemporal protein expression within the biofilm using fluorescence imaging.
• Observed response times for protein induction ranging from 30 minutes to 5 hours.

Conclusions:

• The developed electrochemical flow cell enables simultaneous monitoring of biofilm electrochemistry and protein expression.
• This system is suitable for evaluating the performance of electroactive bacteria for biosensing applications.
• The findings support the development of microbial biofilms as living electronic sensors.