Microscopy videos of microbial motility at high hydrostatic pressure

This dataset includes microscopy videos showing how the motility of hydrocarbon-degrading bacteria is influenced by increased hydrostatic pressure. To obtain this data, a high-pressure microscope chamber (described in Nishiyama and Sowa, 2012, Biophysical Journal) was used. Bacteria were grown in Marine Broth 2216 at 23C and 5C until late log phase, then transferred to the microscope chamber (set to 23C and 7C, respectively). 7C was used (instead of 5C) as it is as cold as we can get the system without compromising data quality. The closed high-pressure chamber was hooked up to a phase-contrast microscope with video capabilities. Two types of experiments were performed: 1) Pressure was incrementally increased by 20 MPa, and 20-second videos of motility were taken at each pressure. Once motility appeared to cease, the system was depressurized incrementally by 20 MPa, and videos were again taken; 2) The samples were pressurized to high pressure and left there for 2 minutes. Then, the pressure was released to atmospheric pressure (0.1 MPa) and the recovery of motility after pressure exposure was recorded.