title: Lactate metabolism by Veillonella parvula.
abstract: A strain of Veillonella parvula M4, which grows readily in lactate broth without a requirement for carbon dioxide, has been isolated from the oral cavity. Anaerobic, washed cells of this organism fermented sodium lactate to the following products (moles/100 moles of lactate): propionate, 66; acetate, 40; carbon dioxide, 40; and hydrogen, 14. Cells grew readily in tryptone-yeast extract broth with pyruvate, oxaloacetate, malate, and fumarate, but poorly with succinate. The fermentation of pyruvate, oxaloacetate, or lactate plus oxaloacetate by washed cells resulted in the formation of propionate and acetate in ratios significantly lower than those observed with lactate as the sole carbon source. This was primarily due to increased acetate production. Cell-free extracts were unable to degrade lactate but metabolized lactate in the presence of oxaloacetate, indicating the presence of malic-lactic transhydrogenase in this organism. Lactic dehydrogenase activity was not observed. Evidence is presented for oxaloacetate decarboxylase and malic dehydrogenase activities in extracts.
mesh_terms: D000085:Acetates / Q000096:biosynthesis; D002245:Carbon Dioxide / Q000096:biosynthesis; D002247:Carbon Isotopes; D002262:Carboxy-Lyases / Q000378:metabolism; D002474:Cell-Free System; D002845:Chromatography; D003124:Colorimetry; D003470:Culture Media; D005285:Fermentation; D006859:Hydrogen / Q000096:biosynthesis; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010071:Oxaloacetates / Q000378:metabolism; D011422:Propionates / Q000096:biosynthesis; D011773:Pyruvates / Q000378:metabolism; D012822:Silicon Dioxide; D013053:Spectrophotometry; D014678:Veillonella / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000085:Acetates; D002247:Carbon Isotopes; D003470:Culture Media; D007773:Lactates; D010071:Oxaloacetates; D011422:Propionates; D011773:Pyruvates; D009243:NAD; D002245:Carbon Dioxide; D012822:Silicon Dioxide; D006859:Hydrogen; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D002262:Carboxy-Lyases