Growth and survival of H. salinarum NRC-1 in rich media. The growth and survival of H. salinarum NRC-1 in Complete Medium (CM) (see materials and methods for composition and growth conditions) was monitored by changes in optical density at 600 nm (OD600) and by replica plating. The left y-axis shows growth versus time as measured by OD600 on a log scale. The corresponding OD600 data is plotted as open circles. The right y-axis indicates the number of colony forming units (CFU) measured from samples versus time. The corresponding CFU data is plotted as closed circles. The dotted oval highlights an apparent growth phase transition.