Time: 9:00 AM, Feb. 22nd, 2011

 

Location: Conference Room, BIOPIC Building, Peking University

 

Presenter: Dr. Fan Bai (Postdoctoral Research Fellow, Osaka University, Japan)

 

Title：Bacterial flagellar motor and bacterial motility

 

Abstract:

 

The bacteria are a large group of single-celled, p rokaryote microorganisms. They are ubiquitous in every habitat on Earth. Pathogenic bacteria are a major cause of human death and disease. Using the transmembrane electrochemical proton (or sodium) motive force as the energy source, the bacterial flagellar motor (BFM) plays a crucial role in both bacterial motility and chemotaxis.

 

Creatures as small as bacteria can sense. They respond to environmental changes in a broad dynamic range with high sensitivity through various t axis systems, eg. chemotaxis, phototaxis, thermotaxis, magnetotaxis. Their ability to detect environmental changes and take subsequent actions to escape from, adapt to or evolve in a new environment are essential for their survival.

 

My talk will start with a general introduction to the bacterial flagellar motor, bacterial motility and chemotaxis. Then I will present a brief review of five research projects I have been worked on in the past, they are: 1) measure the torque-speed relationship of the bacterial flagellar motor 2) measure steps of the bacterial flagellar motor 3) mathematical modeling of the bacterial flagellar motor function 4) turnover and stator exchange in the flagellar motor studied by in vivo imaging 5) switching dynamics of the flagellar motor switch. These research projects demonstrates an intimate collaboration between physics and biology: theory and experimental techniques developed from modern physics have greatly helped our understanding of biological problems.

 

In the last part of my talk, I will introduce my future research plan - system biology study and bioengineering of bacterial taxis. The broad objective of the proposed research is to understand the mechanism of bacterial taxis from a systems biology perspective. By combining the cutting-edge experimental techniques and co mputational models, our goal is to identify the design principles of general bacterial taxis systems. Distinct from previous studies, a special attention will be given to the evolution of the system, such as the molecular and genetic basis of bacterial persistence to a certain stimulus and how to develop or eliminate such persistence. Harnessing the metabolic and motile activity of bacteria can provide energy for a variety of future applications. Recent research also highlights the possibility to harvest useful mechanical work from motile bacteria. We expect bacterial taxis will have potential uses in optimizing microscopic machines.