title: Weissella halotolerans W22 combines arginine deiminase and ornithine decarboxylation pathways and converts arginine to putrescine.
abstract: OBJECTIVE
  To demonstrate that the meat food strain Weissella halotolerans combines an ornithine decarboxylation pathway and an arginine deiminase (ADI) pathway and is able to produce putrescine, a biogenic amine. Evidence is shown that these two pathways produce a proton motive force (PMF).
  
  
  RESULTS
  Internal pH in W. halotolerans was measured with the sensitive probe 2',7'-bis-(2-carboxyethyl)-5(and-6)-carboxyfluorescein. Membrane potential was measured with the fluorescent probe 3,3'-dipropylthiocarbocyanine iodine. Arginine and ornithine transport studies were made under several conditions, using cells loaded or not loaded with the biogenic amine putrescine. ADI pathway caused an increase in DeltapH dependent on the activity of F(0)F(1)ATPase. Ornithine decarboxylation pathway generates both a DeltapH and a DeltaPsi. Both these pathways lead to the generation of a PMF.
  
  
  CONCLUSIONS
  Weissella halotolerans W22 combines an ADI pathway and an ornithine decarboxylation pathway, conducing to the production of the biogenic amine putrescine and of a PMF. Transport studies suggest the existence of a unique antiporter arginine/putrescine in this lactic acid bacteria strain.
  
  
  CONCLUSIONS
  The coexistence of two different types of amino acid catabolic pathways, leading to the formation of a PMF, is shown for a Weissella strain for the first time. Moreover, a unique antiport arginine/putrescine is hypothesized to be present in this food strain.
authors.affiliation: Instituto de Biologia Experimental e Tecnologica (IBET), Universidade Nova de Lisboa, Oeiras, Portugal. cpereira@itqb.unl.pt
authors.forename: C I
authors.initials: CI
authors.lastname: Pereira
authors.forename: M V
authors.initials: MV
authors.lastname: San Romão
authors.forename: J S
authors.initials: JS
authors.lastname: Lolkema
authors.forename: M T Barreto
authors.initials: MT
authors.lastname: Crespo
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001120:Arginine / Q000378:metabolism; D003653:Decarboxylation; D006867:Hydrolases / Q000378:metabolism*; D007778:Lactobacillus / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D009952:Ornithine / Q000378:metabolism*; D018892:Proton-Motive Force; D011700:Putrescine / Q000378:metabolism*
chemical_list: D000255:Adenosine Triphosphate; D001120:Arginine; D009952:Ornithine; D006867:Hydrolases; C019723:arginine deiminase; D011700:Putrescine