Bioconvection induced by phototaxtic behaviors of photosynthetic microorganisms

Nobuhiko J.  Suematsu

Presentation information

[J] Oral

O (Public ) » Public

[O-07] Kitchen Earth Science: its potential for producing diverse goals by hands-on experiments

Sun. May 26, 2024 9:00 AM - 10:15 AM International Conference Room (IC) (International Conference Hall, Makuhari Messe)

convener:Ichiro Kumagai(School of Science and Engineering, Meisei University), Ayako I Suzuki(Toyo University), SHIMOKAWA MICHIKO(Nara Womens University), Kei Kurita(Earth-Life Science Institute, Tokyo Institute of Technology), Chairperson:Ichiro Kumagai(School of Science and Engineering, Meisei University), Ayako I Suzuki(Toyo University), SHIMOKAWA MICHIKO(Nara Womens University), Kei Kurita(Earth-Life Science Institute, Tokyo Institute of Technology)

9:45 AM - 10:00 AM

[O07-04] Bioconvection induced by phototaxtic behaviors of photosynthetic microorganisms

★Invited Papers

*Nobuhiko J. Suematsu¹ (1.Meiji University)

Keywords:convection pattern, microorganisms, phototaxis

Fluidic pattern is observed in variety of scales such as mantle convection and thermal convection observed in "miso-soup." The thermal convection originates from cooling on the surface due to thermal diffusion. The low temperature induces high density. Therefore, the density instability occurs. In this time, we will introduce similar convection pattern that is induced by phototaxis of microorganisms, Euglena. Euglena is photosensitive microorganisms which swim away from strong light source, which is called "phototaxis." Due to the negative phototaxis, the microorganisms gather on the surface of culture with illumination from the bottom. The microorganisms are heavier than aqueous phase. Therefore, density instability is induced and convection pattern is formed. In my presentation, I will introduce several characteristic behaviors observed in the culture of Euglena.