Abstract:
Extracts from cells of Rhodospirillum rubrum cultured photoeterotrophically under anaerobic conditions exhibit and NAD+ dependent, soluble aldehyde dehydrogenase which catalyses the dehydrogenation of acetaldehyde to acetate (aldehyde: NAD oxidoreductase. EC '1.2.1.3). The enzyme is NAD+ specific with the aldehydes tested, no activity is observed with NADP or in the absence of NAD+ Suif-hydryl reagents markedly increase the aldehyde dehydrogenase activity. For initial reaction rates of acetaldehyde dehydrogenation the optimum activity of the enzyme is between pH 9.? to 9.5, with an apparent Michaelis constant for acetaldehyde of 10 M. N o requirements for potassium or orthophosphate are apparent. Extracts from cells cultured anaerobically on ethanol, as the sole carbon source, exhibit five to ten times the specific aldehyde dehydrogenase activity compared to cell cultured on malate plus glutamate. This increase in the specific activity of aldehyde dehydrogenase preparation from cells cultured or ethanol is inhibited by proflavin or chlor-amphenicol. The evidence suggests that the aldehyde dehydrogenase in R. rubrum is an inducible enzyme.
Page(s):
51-59
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Botany, Volume: 14, Issue: 1, Year: 1982