Implications of electric potentials applied on a denitrifying process

Area of Science:

• Environmental microbiology
• Biotechnology
• Electrochemistry

Background:

• Denitrification is a crucial microbial process for nitrogen removal.
• Electric potentials (EP) can influence microbial metabolism.
• Understanding EP effects is vital for optimizing bioremediation.

Purpose of the Study:

• To investigate the impact of applied electric potentials on the denitrifying process.
• To explore the oxidation of p-cresol under different EP conditions.
• To elucidate the biochemical effects of EP on microbial consortia.

Main Methods:

• Application of three distinct electric potentials (+104, -187, -279 mV) to denitrifying sludge.
• Monitoring of p-cresol oxidation and nitrogen compound transformation.
• Analysis of substrate transport and biochemical changes.

Main Results:

• EP facilitated p-cresol oxidation without nitrate but required an electron donor for denitrification.
• Applied EP uncoupled oxidation and reduction, favoring p-cresol oxidation over N2 production.
• Specific EP affected nitrate/nitrite consumption and p-hydroxybenzoate transformation, while -187 mV impacted substrate transport.

Conclusions:

• Denitrification exhibits distinct physiological responses to different applied electric potentials.
• EP can modulate microbial activity, influencing substrate oxidation and nitrogen cycling.
• This research provides insights into electrochemically assisted microbial processes for environmental applications.