Microbial motility

H. akashiwo cells swimming (real time) in a 4 mm high vertical chamber. The cells are about 15 micrometers in size and swim against gravity (negatively gravitactic). Under stationary condition, most of the cells accumulate in the upper portion of the chamber. Video credit: Anupam Sengupta

Gravitaxis of H. akashiwo cells. The cells can be seen here swimming (real time) upward against gravity, imaged right after the confining chamber was reoriented by 180 degrees in the vertical plane. The average vertical swimming speed is around 60 micrometers/s. Video credit: Anupam Sengupta

Close up video of swimming H. akashiwo population. The cells are about 15 micrometers in size, and exhibit a helical swimming motion. The video is captured close to the upper boundary of the vertical chamber. Video credit: Anupam Sengupta


Dense suspension of motile bacteria (Bacillus subtilis wild-type strain OI1085) in a microfluidic channel 40um
deep, 5mm wide. The cell concentration is 2×10 10cells/ml. The video is taken at 370 fps. The field of view is 200×200 um. The complete (longer, uncompressed) video is available here. Video credit: Eleonora Secchi

Dense suspension of motile bacteria (Bacillus subtilis wild-type strain OI1085) flowing from right to left at a flow rate Q= 25 μl/h in a channel 320 um deep, 200 um wide (a 400um long section is shown). The video is taken at 370 fps. The complete (longer, uncompressed) video is available here. Video credit: Eleonora Secchi