acetyl-CoA + H2O + oxaloacetate = citrate + CoA + H(+) Carbohydrate metabolism; tricarboxylic acid cycle; isocitrate from oxaloacetate: step 1/2. Abundant after 6-12 hours of growth. It is not significantly expressed after 24 hours, which is several hours after entering the stationary phase of growth. Citrate synthase is found in nearly all cells capable of oxidative metabolism. Belongs to the citrate synthase family.