紀要論文

光ピンセット法と蛍光観察を用いた極べん毛モーターの回転計測

POLAR FLAGELLAR ROTATION MEASURED BY OPTICAL TWEEZERS AND FLUORESCENCE OBSERVATION

jpn

24368083

https://doi.org/10.15002/00025416

法政大学大学院理工学研究科

法政大学大学院紀要. 理工学研究科編

63

1

2

2022-03-24

Version of Record

Many bacteria swim in aqueous environments, propelled by rotating their flagella. The shape of the flagellum is known to be unique to each type of bacteria. The shape and the location of the flagellum is known to be unique to each type of bacteriabacterial species. Some bacteria, such as Vibrio alginolyticus and Actinoplanes missouriensis, have their flagella at the cell pole. It is important to measure polar flagellar rotation to understand their function, however, only a few results of speed measurements of polar flagella have been published due to the difficulty of rotation measurements because of their location. In this study, we aimed to observe the polar flagellar rotation in Actinoplanes missouriensis, which has many short polar flagella and can swim at up to 200 μm/s. We first attempted to apply optical tweezers to a single polar flagellum of V. alginolyticus, and confirmed that we could estimate its motor speed from the periodic fluctuations of the trapped cell body position. We then applied the same method to the motor of A. missouriensis, and found that the optical tweezers were not suitable for measuring the motor speed of A. missouriensis because there was no correlation between the periodic fluctuation of cell position and swimming speed. Therefore, we labeled the flagella of A. missouriensis by fluorescent dyes and directly observed the motor rotation by fluorescence microscopy, and found that the motor rotation speed was much slower than expected from the swimming speed.

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