Wine composition plays an important role in the control of carcinogenic precursor formation by Lactobacillus hilgardii X₁B.

Background: Lactobacillus hilgardii, a wine lactic acid bacterium, is able to use arginine, through the arginine deiminase pathway with the formation of citrulline, a precursor of the carcinogen ethyl carbamate. The influence of different Argentine wine varieties (Merlot, Cabernet Sauvignon and Malbec), on bacterial growth and arginine metabolism was examined. Furthermore, the effect of different components normally present in wines on the enzyme activities of the arginine deiminase system was determined.

The role of two families of bacterial enzymes in putrescine synthesis from agmatine via agmatine deiminase.

Putrescine, one of the main biogenic amines associated to microbial food spoilage, can be formed by bacteria from arginine via ornithine decarboxylase (ODC), or from agmatine via agmatine deiminase (AgDI). This study aims to correlate putrescine production from agmatine to the pathway involving N-carbamoylputrescine formation via AdDI (the aguA product) and N-carbamoylputrescine amidohydrolase (the aguB product), or putrescine carbamoyltransferase (the ptcA product) in bacteria. PCR methods were developed to detect the two genes involved in putrescine production from agmatine.

Phenolic compound combinations on Escherichia coli viability in a meat system.

The aim of this work was to investigate the antibacterial activity of flavonoid and nonflavonoid phenolic compound combinations and the synergistic antibacterial effects against Escherichia coli ATCC 35218. In nutrient medium, the combinations of gallic and protocatechuic acids, gallic and caffeic acids, and rutin and quercetin were the best antibacterial agents, with synergistic effects, and were selected to test their activity in a meat model system. All combinations diminished the bacterial growth, without cellular death at 20 degrees C.

Inhibition of growth and ochratoxin A biosynthesis in Aspergillus carbonarius by flavonoid and nonflavonoid compounds.

The effect of naturally occurring phenolic compounds on Aspergillus carbonarius growth and ochratoxin A (OTA) production was studied. Caffeic acid and the flavonoids, rutin and quercetin, were added to Czapek Yeast Extract agar at concentrations ranging between 50 and 500 mg/l. All phenolic compounds had a significant influence on growth rate and lag phase of A.

Growth parameter and viability modifications of Escherichia coli by phenolic compounds and Argentine wine extracts.

The anti-bacterial effect of pure non-flavonoids gallic, vanillic, protocatechuic, and caffeic acids and flavonoids quercetin, rutin, and catechin and the effect of total polyphenols of three Argentinean wine varieties, Cabernet Sauvignon, Malbec, and Merlot, against Escherichia coli, microorganism frequently detected in fresh and processed foods, was investigated. The hydroxycinnamic derivate caffeic acid and the flavonoid quercetin were the more effective against E. coli.

Influence of ethanol and low pH on arginine and citrulline metabolism in lactic acid bacteria from wine.

The aim of this work was to study the effects of ethanol on cell growth and arginine and citrulline metabolism in two heterofermentative lactic acid bacteria from wine, and to determine their possible association with the formation of ethyl carbamate (EC), a carcinogenic compound. Lactobacillus hilgardii X1B is able to utilize arginine and citrulline, while Oenococcus oeni m can only use citrulline, a precursor of EC. Growth of both microorganisms was partially inhibited by 10 and 15% (v/v) ethanol.

Effect of dipeptides on the growth of Oenococcus oeni in synthetic medium deprived of amino acids.

Oenococcus oeni has numerous amino acid requirements for growth and dipeptides could be important for its nutrition. In this paper the individual or combined effect of dipeptides on growth of O. oeni X2L in synthetic media deficient in one or more amino acids with L-malic acid was investigated.

Metabolism of gallic acid and catechin by Lactobacillus hilgardii from wine.

The ability of Lactobacillus hilgardii 5w to metabolize gallic acid and catechin was evaluated. It was grown in a complex medium containing gallic acid or catechin. The metabolites were analyzed by high-performance liquid chromatography and identified by comparing the retention times and spectral data with the standards of a database.

The arginine deiminase pathway in the wine lactic acid bacterium Lactobacillus hilgardii X1B: structural and functional study of the arcABC genes.

The genes implicated in the catabolism of the amino acid arginine by Lactobacillus hilgardii X(1)B were investigated to assess the potential for formation of ethyl carbamate precursors in wine. L. hilgardii X(1)B can use arginine via the arginine deiminase pathway.

Comparative survey in Lactobacillus plantarum of the growth and metabolism of arginine and citrulline in different media.

Arginine deiminase activity increased in the presence of arginine in Lactobacillus plantarum strains N4 and N8 isolated from orange. The influence of citrulline and ornithine on arginine deiminase and ornithine transcarbamylase activities was strain-dependent. The growth and arginine and citrulline metabolism of L.

Effect of wine phenolic compounds on Lactobacillus hilgardii 5w viability.

After 6 days of Lactobacillus hilgardii 5w incubation at 4 degrees C, the viable cell counts diminish 31.9, 45.6, and 89.

Acetaldehyde Production by Strains Used as Probiotics in Fermented Milk.

Lactic acid bacteria have diverse shunts for the metabolism of acetaldehyde, which is involved in the metabolism of carbohydrates, proteins and nucleic acids. In Lactobacillus acidophilus and Lactobacillus casei , strains isolated from feces of healthy children, acetaldehyde can be formed from different sources. Phosphotransacetilase, acetate kinase, aldehyde dehydrogenase and 2-deoxiriboaldolase activities were found in both strains.