FIG. 4.
Effect of NO on oxygen respiration. R. capsulatus strains were grown under photoheterotrophic conditions, harvested, and resuspended in fresh RCV-malate growth medium. The rate of oxygen respiration by 2 mg (dry weight) of R. capsulatus contained in a volume of 3 ml was monitored in a Clark-type electrode maintained at 30°C. (A) Inhibitory effect of NO on R. capsulatus PAS100. (B) Inhibitory effect of NO on R. capsulatus MC111. (C) No discernible inhibition of oxygen respiration by 12 nmol of NO added to a suspension of R. capsulatus PAS100 containing plasmid pRKMC401. In each case, NO additions were made at [O2] = 100 μM.