SPECIFIC FEATURES OF CARBON METABOLISM IN COLORLESS SULFUR BACTERIUM MACROMONAS BIPUNCTATA

The activity of the enzymes of the tricarboxylic acid cycle (TCA cycle ) and the glyoxylate cycle was determined for the first time in the un icellular colorless sulfur bacterium Macromonas bipunctata, strain D-4 05. The complete TCA cycle was established to function in M. bipunctat a, its sole peculiarity being low fumarate hydratase activity, which c aused fumarate accumulation in the cultivation medium. The glyoxylate cycle was demonstrated to function in M. bipunctata, along with the TC A cycle, regardless of the carbon source utilized. It is suggested tha t the glyoxylate cycle compensates for the low activity of fumarate hy dratase, shunting the conversion of fumarate to malate. Calcium oxalat e formation and intracellular accumulation was revealed as another pec uliarity of carbon metabolism in M. bipunctata.