Figure 3.

Fluorescence microscopy images for measuring bacteria viability, in which live bacterial cells appear green and dead bacterial cells appear yellow/red. Images for bacteria in the supernatant (a) and sediment (b) at the low-surface-tension peak of Figure 1c demonstrate a viability ratio of 35% ± 5% and 99% ± 1%, respectively. Images for bacteria in the supernatant (c) and sediment (d) at the high-surface-tension peak of Figure 1c demonstrate a viability ratio of 99% ± 1% and 97% ± 1%, respectively.