Figure 5.

Effect of cyanide on the induction of OLE1 and CYC7 after a shift to anoxic conditions. Strain JM43 was grown aerobically for at least six generations to early log-phase; the sparge gas was then switched from air to 2.5% CO₂ in O₂-free N₂. After achieving anaerobiosis (1 h), an anoxic solution of KCN (1 mM final concentration) was added. Cells were harvested at the indicated times, and total RNA was isolated and subjected to Northern blot analyses as described in Materials and Methods. Transcript levels were normalized to the level of ACT1 mRNA and are presented as a decimal percent of their steady-state levels under anoxic conditions (lane 9). Lane 1, aerobic cells before the shift; lane 2, 1 h after the shift, just before KCN addition; Lanes 3–8, 5 h, 9 h, 13 h, 17 h, 21 h, and 25 h, respectively, after the shift.