Day: 10th December (8 am Pacific Standard Time, 5 pm Central Europe Time)
Speaker: Sara Tejedor Sanz
Affiliation: Senior Scientific Engineer Associate at the Advanced Biofuels Process Development Unit, Lawrence Berkeley National Lab, USA
Title: Extracellular electron transfer in lactic acid bacteria: squeezing fermentation using electrodes as redox sink
Abstract: The strategy that microorganisms use to extract energy dictates their environmental niche and their interactions with other organisms. Recently, we identified a widespread electron transfer pathway in lactic acid bacteria that allows these microorganisms to reduce extracellular electron acceptors. These species play a major, beneficial role in food fermentation and maintenance of a healthy gut microbiome. The presence of this extracellular electron transfer pathway in lactic acid bacteria was extremely surprising because they are believed to have abandoned electron transfer chains and conserve energy almost exclusively via fermentation. Our research now shows that lactic acid bacteria induce extracellular electron transfer genes and use an anode as electron acceptor to conserve energy and accelerate fermentation under laboratory conditions. Thus, the use of extracellular electron transfer could give lactic acid bacteria a fitness advantage in outcompeting other microorganisms in an ecological context. Additionally, we have investigated whether this metabolism could provide a biotechnological application by changing the flavor and texture of fermented foods.