FIG. 2.

Analysis of puf mRNA in R. sphaeroides strains grown anaerobically with DMSO by continuous sparging with a mixture of 95% N₂–5% CO₂ to an optical density at 600 nm of 0.45 to 0.55 or aerobically by sparging with 30% O₂–69% N₂–1% CO₂ to an OD₆₀₀ of 0.4 to 0.5. Approximately 20 μg of total RNA was loaded in each lane. The Northern blots were probed with a labeled 0.47-kb StyI fragment from pUI655 or a 0.5-kb HindIII-PstI fragment from pUCP6.37, which is specific for puf mRNA or processed 23S rRNA (14S), respectively (B). After background correction the values were normalized to the levels of processed 23S rRNA (14S). The normalized values are plotted above the Northern blots. The transcript level in the wild type (2.4.1) with pRK415 grown under anaerobic condition was set at 100 (A). PRRB1, the prrB-negative strain PrrB1. Electrophoresis and Northern blotting were performed at the same time using the same agarose gel and nylon membrane.