title: alpha-Ketoglutarate biosynthesis in wild and industrial strains of Lactococcus lactis.
abstract: OBJECTIVE
  This study was carried out to explore the ability of wild and industrial strains of Lactococcus lactis to produce alpha-ketoglutarate (alpha-KG), which is essential during the conversion of amino acids to flavour compounds.
  
  
  RESULTS
  Two pathways in alpha-KG biosynthesis were explored in strains of L. lactis isolated from dairy products, vegetables and commercial dairy starter cultures. Half of the strains efficiently converted glutamine to glutamate (Glu) and grew in Glu-free medium. Strains did not present isocitrate dehydrogenase and aconitase activities. However, half of the strains presented glutamate dehydrogenase (GDH) activity.
  
  
  CONCLUSIONS
  The ability of L. lactis to synthesize either alpha-KG or Glu via GDH was confirmed. However, L. lactis strains were not able to biosynthesize alpha-KG by the citrate-isocitrate pathway. NADP-GDH activity was mainly found in strains isolated from vegetables, whereas NAD-GDH activity was mainly found in strains isolated from dairy products.
  
  
  CONCLUSIONS
  The origin of isolation highly influenced NAD or NADP-GDH activities. These enzymatic activities may be correlated to the flavour production capacity of the different strains.
authors: Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD, A.C.), Carretera a la Victoria Km. 0.6, Hermosillo, Sonora, México.
authors: N
authors: N
authors: Gutiérrez-Méndez
authors: E
authors: E
authors: Valenzuela-Soto
authors: A F
authors: AF
authors: González-Córdova
authors: B
authors: B
authors: Vallejo-Cordoba
mesh_terms: D005969:Glutamate Dehydrogenase / Q000502:physiology; D018698:Glutamic Acid / Q000096:biosynthesis; D007656:Ketoglutaric Acids / Q000378:metabolism*; D013294:Lactococcus lactis / Q000254:growth & development / Q000378:metabolism*; D009249:NADP / Q000378:metabolism
chemical_list: D007656:Ketoglutaric Acids; D018698:Glutamic Acid; D009249:NADP; D005969:Glutamate Dehydrogenase