Alexandros A. Fragkopoulos
University of Bayreuth, Department of Physics, Experimental Physics of Soft and Living Matter
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Light-sensitive Microbes and Living Fluids – The role of light on the motility, adhesion, and self-organization
Photosynthetic microbes have evolved and successfully adapted to their ever-changing environmental conditions in a multitude of diverse habitats and ecosystems on Earth. Their ability to dynamically respond to alterations of the luminous intensity, using biological processes such as phototaxis, surface association and diurnal cell cycles, are pivotal for their survival. Even in the absence of light, the microbes can still sustain their biological functionalities through aerobic respiration, and even in anoxic conditions through anaerobic metabolic activity. Thus, it is essential to understand the microbial response at different light- and metabolic- conditions and the relation of such changes to emergent behavior.
In this presentation, I will show how methods and concepts from soft matter and biological physics allow us to decipher fundamental physical principles of the light response of photoactive microorganisms. In the first part, I will focus on the interactions of photosensitive microbes with surfaces and discuss how the adhesion of living microbes has adapted to the light conditions and can even be reversed within seconds. In the second part, I will focus on the connection of microbial motility with their metabolic activity, and how it is connected to the emergence of collective phenomena, such as coherent flows and self-organization of living suspension.
