Citrate Cycle Intermediates in the Metabolism of Aspartate and Lactate by Propionibacterium freudenreichii subsp. shermanii.

Propionibacterium freudenreichii subsp. shermanii metabolized 7 mol of aspartate to 6 mol of succinate, 4 mol of CO(2), and 7 mol of ammonia. When lactate, sparged with 100% CO(2), was fermented at pH 5.5, unexpectedly high ratios of propionate to acetate were obtained (i.e., 3.2 to 3.8:1). Citrate cycle intermediates may be involved in these fermentations.