Alcohol dehydrogenase activity of nonsulfur purple bacteria

Rhodopseudomonas palustris, Rh. viridis, Rh. acidophila, and Rhodomicrobium vanniellii grow on media containing ethanol, n-propanol, and n-butanol. The highest amount of lower alcohols is utilized by the strains of Rh. palustris. Only Rh. acidophila accumulates methanol. Alcohol dehydrogenase of Rh. palustris, Rh. viridis, and Rhodospirillum rubrum requires for its activity NAD, that of Rhodomicrobium vanniellii--NADP, and the enzyme of Rh. acidophila is active in the presence of phenazine metasulphate (PMS) and ammonium ions. Aldehyde dehydrogenase from two strains of Rh. palustris also requires NAD; the Nakamura strain is active in the presence of PMS. Aldehyde dehydrogenase of Rh. acidophila is active in the presence of PMS and ammonium ions. Different bacterial species vary in the substrate specificity of their alcohol dehydrogenases.