P-333 - Electrochemically Active Soil Biofilms Respond to Simulated Root Exudates

Soil health is essential for supporting plant growth and ecological functions, assessed through factors such as nutrient availability, crop productivity, and the diversity of soil microbial communities. Soil microorganisms interact to form complex biofilms, which play a pivotal role in nutrient cycling. However, investigating microbial activity in soil remains challenging due to its inherent complexity, heterogeneity, and the limitations of current technologies for real-time monitoring. Notably, soil microbes generate electrochemical currents during metabolic processes via electron transfer mechanisms. This current can be monitored in real-time using inert electrodes, providing a novel and effective approach to studying microbial metabolism. We conducted a soil reactor experiment to investigate the impact of nutrient amendments, including primary plant root exudates (glucose, sodium acetate, and malic acid), on microbial community structure under varying polarization potentials (cathodic and anodic). The study revealed that unique microbial communities were selectively enriched within the reactor system depending on the specific carbon source amendments and polarization potentials applied. This research aims to correlate soil microbes enriched by each carbon source to overall soil health and microbiome function with measured electrochemical signals. Future work will study how electrical potentials affect microbial communities and plant growth under treatments like manipulating source microbial and N addition, aiming to drive microbes toward beneficial state for plant.