To evaluate the influence of gas vacuoles on the settling behavior
of Arthrospira filaments, the settling velocity was compared
between filaments with intact gas vacuoles and filaments with collapsed
gas vacuoles. Gas vacuoles were collapsed by applying pressure
to the cell suspension in a closed syringe (Kim et al., 2005).
Phase contrast microscopy was used to verify the gas vacuole
diminishment after the pressure treatment.