FIGURE 7.

Phenotypic analysis of the SigE overexpression strain. A, cultures of the GT and GOX50 cells were spotted onto modified BG-11 plates with/without 5 mm glucose. Each spot consisted of 2 μl of culture diluted to an A₇₃₀ of 2.0, 1.0, or 0.5 as indicated. The plates were incubated in the light and photographed 4 days after inoculation. B, cells were spotted onto plates as in A, incubated in continuous darkness for 3 days, and then transferred to the light. Plates were photographed 4 days after the shift from dark to light. C, growth curves of cells under photoautotrophic (PA) or photomixotrophic (PM) conditions. For photomixotrophic conditions, 1 mm glucose was supplemented in modified BG-11 liquid medium. Data represent means ± S.D. of values from three independent experiments. Differences between GT and GOX50 analyzed using Student's t test were statistically significant (*, p < 0.05; **, p < 0.005). D, growth curves of cells under light-activated heterotrophic conditions (LAHG). The cells were grown in modified BG-11 liquid medium with 1 mm glucose. The cells were grown under continuous dark conditions, except for exposure to white light for 15 min per day.