Effect of growth condition on enzymes of the citric acid cycle and the glyoxylate cycle in the photosynthetic bacteriumRhodopseudomonas palustris

✍ Scribed by J. H. Eley; K. Knobloch; T. -W. Han

• Publisher: Springer Netherlands
• Year: 1979
• Tongue: English
• Weight: 452 KB
• Volume: 45
• Category: Article
• ISSN: 0003-6072
• DOI: 10.1007/bf00403652

✦ Synopsis

Effect of growth condition on enzymes of the citric acid cycle and the glyoxylate cycle in the photosynthetic bacterium Rhodopseudomonaspalustris. Antonie van Leeuwenhoek 45" 521 529.

The enzymes of the citric acid and glyoxylate cycles as well as RuBP 4 carboxylase were measured in cell-free extracts from Rhodopseudomonas palustris after growth under chemoheterotrophic, photoheterotrophic and photolithotrophic conditions. Although the citric acid cycle was found to be complete under all growth conditions, significant differences in certain enzyme activities occurred as a function of the different energy sources applied. The glyoxylate cycle also was complete under all growth conditions with highest isocitrate lyase activity seen after photoheterotrophic growth on acetate. Photo-and chemoheterotrophic growth on malate reduced the isocitrate lyase. The activity was not repressed further by photolithotrophic growth on thiosulfate. RuBP carboxylase activity, present under photolithotrophic conditions, was repressed by chemoheterotrophic growth but was not decreased by the presence of organic substrates during photoheterotrophic growth.