FIG. 4.

(A) β-Galactosidase activities from cell extracts of R. sphaeroides strains containing the dorS::lacZ transcriptional fusion plasmid pNMT77. (B) β-Galactosidase activities from cell extracts of R. sphaeroides strains containing the dorR::lacZ transcriptional fusion plasmid pNMT94. Strains are 2.4.1^T (░⃞) and CCOP1 (■). Growth conditions are as follows: AER, aerobically; ANA, anaerobically in the dark; PS, photosynthetically at a light intensity of 10 W m⁻². Where indicated cultures were supplemented with DMSO to a final concentration of 60 mM. Results are the mean values from triplicate assays of at least three independent cultures and are corrected for activity from the vector alone under the same conditions (pML5, <35 μmol of o-nitrophenol [ONP] formed min⁻¹ mg of protein⁻¹). Vertical bars represent the standard deviations from the means.