Aspects of carbon metabolism in Chloroflexus

When fluoroacetate was added to aerobic, washed cells of Chloroflexus, O₂ uptake was strongly inhibited and citrate accumulated. Under anaerobic conditions in the light, fluoroacetate inhibited CO₂ uptake and caused citrate accumulation. The results are taken as evidence for the operation of a tricarboxylic acid cycle in Chloroflexus both under aerobic conditions in the dark and anaerobically in the light. 2. Organic compounds are assimilated into the storage materials polyglucose and poly--hydroxybutyric acid by washed cells of Chloroflexus. The type of storage product formed from acetate depends upon the availability of reducing power. 3. Low activities of the key enzymes of the reductive pentose phosphate cycle, ribulose-1,5-bisphosphate carboxylase and phosphoribulokinase were detected in cell free extracts of photoheterotrophically grown Chloroflexus.Abbreviations RuBP Ribulose-1,5-bisphosphate - TCA tricarboxylic acid - PHB poly--hydroxybutyric acid