Speaker:
Albert Siryaporn
Date:
Thursday, January 13, 2022
Time:
3:30 pm
Location:
RH 101
Cells are biological units that organize into structures that give rise to new properties and collective functions. Bacteria are one of the simplest and oldest forms of life and exist as individual cells. Individual bacterial cells self-organize with other bacteria into dense collectives known as biofilms. I will describe the work our lab has performed at UCI on phenomena that emerge due to physical interactions between neighboring bacterial cells in biofilms. In particular, we have investigated emergent phenomena in bacteria that are in moving fluids, on porous surfaces, and in animal host environments. Bacteria inhabit environments that contain moving fluids, such as the vasculature of plants and animals. We describe how bacteria self-organize and disperse in complex fluidic networks using a cyclical process that we have termed dynamic switching. We have adapted fluorescence lifetime imaging microscopy (FLIM) to measure the states of electron carriers within bacteria during dynamic switching and find that a significant change in electron flow accompanies bacterial movement in fluids. On porous surfaces, bacterial collectives produce a layer of viscous fluid that transports them across relatively large distances. We describe how collectives coordinate to avoid areas containing stressors including antibiotics and bacterial viruses by altering the fluidic properties of the transport layer. In animal hosts, bacteria are repelled by defenses from the animal’s immune system. We describe a novel immune defense mechanism that infiltrates bacterial cells and reorganizes their DNA, thus killing bacteria with high efficacy. This mechanism has important implications for how bacteria resist antibiotics and for the development of n
Host:
Kevork Abazajian