Figure 1.
From: Complete genome sequence of “Thioalkalivibrio sulfidophilus” HL-EbGr7
a, Enrichment of “Thioalkalivibrio sulfidophilus” HL-EbGr7 in a gradient culture, whereby sulfide is diffusing from an agarose plug in the bottom of the cylinder and O2 from the top. The bacterial cells accumulate in a dense band at the most favorable sulfide and oxygen concentration. b, phase-contrast microphotograph; c, electron microscopy microphotograph of a total cell preparation contrasted with phosphotungstic acid.