Physiology of the wall-less Anaeroplasmataceae (Class Mollicutes) and related walled bacteria

Cell-free extracts of two strictly anaerobic molllcutes, Anaeroplasma intermedium SLA and Asteroleplasma anaerobium 161?, were tested for enzymic activities of Intracellular carbohydrate metabolism. As. anaerobium was also tested for enzymes of purine and pyrimidine metabolism. Both organisms had enzymic activities associated with the nonoxidative portion of the pentose phosphate pathway, and with the Embden-Meyerhoff-Parnas pathway. The 6-phosphofructokinase (PFK) of /Is. anaerobium was ATP-dependent, whereas the PFK of An. intermedium was pyrophosphate-dependent (PPi-dependent). The two anaerobic molllcutes also differed with respect to the enzymes that converted phosphoe/70/pyruvate (PEP) to pyruvate; An. intermedium had pyruvate kinase activity, but /4s. anaerobium had pyruvate, orthophosphate dikinase activity (PPi-dependent). Both organisms had lactate dehydrogenase activity that was activated by fructose 1,6-bisphosphate (Fru-1,6-P2). An. intermedium had activity for PEP carboxykinase (activated by Fru-1,6Pz), but As. anaerobium did not. PEP carboxytransphosphorylase activity was not detected in either organism. An. intermedium had malate dehydrogenase and isocitrate dehydrogenase activities, but it had no activities for the three other tricarboxylic acid cycle enzymes examined; As. anaerobium had malate dehydrogenase activity only. /4s. anaerobium had enzymic activities for the interconversion of purine bases,