title: Regulation of hdc expression and HDC activity by enological factors in lactic acid bacteria.
abstract: OBJECTIVE
  The aim of this work was to study the influence of enological factors on the histidine decarboxylase gene (hdc) expression and on histidine decarboxylase enzyme (HDC) activity in Lactobacillus hilgardii, Pediococcus parvulus and Oenococcus oeni.
  
  
  RESULTS
  Cell extracts and whole cells were used. Glucose, fructose, malic acid and citric acid diminished the hdc expression. Ethanol did not increase hdc expression or activity in cells, but increased HDC activity. Temperature and pH had effect on the activity of HDC but not on hdc expression. Tartaric acid and l-lactic acid, and sulphur dioxide (SO(2)) had no effect on enzyme synthesis and activity. Bacterial species differ in the relative enzymatic activity but all the factors affected similarly to L. hilgardii, P. parvulus and O. oeni.
  
  
  CONCLUSIONS
  The hdc gene expression was lowered by glucose, fructose, malic acid, and citric acid, whereas ethanol enhanced the HDC enzyme activity. The conditions that normally occur during malolactic fermentation and later on, could favour histamine production. SO(2) could prevent bacterial growth, but does not diminish the HDC enzyme activity.
  
  
  CONCLUSIONS
  Information on hdc expression and HDC activity can contribute to the prevention of histamine formation during wine production and storage.
authors: ENOLAB, Departament de Microbiologia i Ecologia, Facultat de Ciències Biològiques, Universitat de València, Burjassot, Valencia, Spain.
authors: J M
authors: JM
authors: Landete
authors: I
authors: I
authors: Pardo
authors: S
authors: S
authors: Ferrer
mesh_terms: D003470:Culture Media / Q000737:chemistry*; D003998:Dicarboxylic Acids; D005285:Fermentation / Q000235:genetics; D005632:Fructose; D005786:Gene Expression Regulation; D005947:Glucose; D006640:Histidine Decarboxylase / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007777:Lactobacillaceae / Q000201:enzymology* / Q000235:genetics; D007778:Lactobacillus / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D007934:Leuconostoc / Q000201:enzymology / Q000235:genetics; D010376:Pediococcus / Q000201:enzymology / Q000235:genetics; D013458:Sulfur Dioxide; D013696:Temperature
chemical_list: D003470:Culture Media; D003998:Dicarboxylic Acids; D013458:Sulfur Dioxide; D005632:Fructose; D006640:Histidine Decarboxylase; D005947:Glucose