Production and degradation of formate by Veillonella dispar ATCC 17745.

Under strictly anaerobic conditions, the resting cells of V. dispar ATCC 17745 produced formate as well as acetate and propionate from pyruvate or from lactate. Pyruvate formate-lyase activity was found when the activity was assayed under strictly anaerobic conditions. Under aerobic conditions, however, the resting cells did not produce formate from pyruvate or from lactate, though the cells actively metabolized pyruvate or lactate (mainly to acetate). This was ascribed to pyruvate formate-lyase activity being easily lost when the cell-free extract was exposed to the air. A part of the produced formate was further degraded to CO2 by the resting cells.