EESS seminar talk on "Connecting electroactivity and prophages in lactic acid bacteria"

Controlling fermentations with electrodes could allow new process development, for instance increasing rates/yields in a biorefinery or developing new food or agroproducts. In nature, diverse primarily-fermentative bacteria encode recently-described pathways to exchange electrons with their environment, suggesting that electroactivity may be important to understand how primary fermenters perform their piece of the carbon cycle. Despite these pathways, it’s remained a challenge to use electrodes to alter how mixed microbial communities ferment. I show that providing an electrode to the model lactic acid bacterium Lactiplantibacillus plantarum can be a two-edged sword: allowing more energetically favorable fermentations but also inducing a prophage which was uninducible by canonical triggers and increasing the lysis rate >10-fold. I’ll connect this finding with prior work by myself and others on microbiome engineering and discuss current work on how electroactivity and phages contribute to spatial structuring of communities.

Aaron is a postdoctoral researcher at EPFL and the Swiss Federal Institute of Aquatic Science and Technology (Eawag), where he studies and engineers microbial interactions to advance sustainable water treatment and resource recovery technologies. Following two years of technology piloting at DC Water’s Blue Plains facility, he went on to earn his PhD in Civil and Environmental Engineering from Princeton University, where he worked with Zhiyong Jason Ren to develop new control strategies for fermentation and anaerobic digestion processes. He is working with Wenyu Gu (EPFL) and Martin Ackermann and Olga Schubert (Microbial Systems Ecology, Eawag) and developing new single-cell methods to study how microbes exchange electrons with each other and with their natural and engineered environments.