EOS · Engineering of bacteria to see light

EOS wants to create a new class of biohybrid living materials capable to perceive light and perform tasks remotely (i.e. drug delivery in hard-to-reach body locations). I propose to achieve this by inducing light sensitivity into non-photosynthetic motile bacteria at minimum invasiveness and complexity. Based on the notion that the active manipulation of the bacteria membrane potential allows controlling bacterial functions, including motion, EOS challenge is how to trigger effectively a membrane potential dynamics. EOS will employ a materials-based approach that I call “optobacterial-stimulation” and is composed by two key ingredients: i. light as a spatiotemporal precise tool that can control bacteria remotely; ii. phototransducing organic materials that associate spontaneously with bacterial cells without the need for neither covalent attachment nor genetic modification. The phototransducing mechanism stems from the “cross-talking” between molecular excitations and the polarization state of cells. The photoinduced membrane potential dynamics is ultimately linked to ion motive force, and thus to the bacterial flagellar motor. All these abovementioned elements have in common the study of light-matter interaction, which represents my main research interest in the last decade. Using optobacterial-stimulation I will answer to three outstanding questions that are related to each other and shape EOS objectives: i. can we engineer bacteria to perceive light through exogenous phototransducers? ii. are bacteria able to perceive different photostimulation approaches, as dictated by molecular excited states, in terms of membrane potential dynamics and motion? iii. can we understand the relationship between the fate of excited states and bacterial function? In the case study, I will demonstrate phototactic guidance of “eyeless” bacteria that are competent to swim in the gastrointestinal tract, with the view to develop intrinsically bio-compatible microswimmers.