Lactic acid bacteria isolated from apples are able to catabolise arginine.

We investigated the potentiality of lactic acid bacteria (LAB) isolated from two apples variety to utilize arginine at different initial pH values. Apples surface contained average levels of bacteria ranging from log 2.49 ± 0.

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.

Influence of phenolic compounds on the growth and arginine deiminase system in a wine lactic acid bacterium.

The influence of seven phenolic compounds, normally present in wine, on the growth and arginine deiminase system (ADI) of Lactobacillus hilgardii X1B, a wine lactic acid bacterium, was established. This system provides energy for bacterial growth and produces citrulline that reacts with ethanol forming the carcinogen ethyl carbamate (EC), found in some wines. The influence of phenolic compounds on bacterial growth was compound dependent.

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.

Interaction between Oenococcus oeni and Lactobacillus hilgardii isolated from wine. Modification of available nitrogen and biogenic amine production.

During the mixed culture of Lactobacillus hilgardii 5w, a common spoilage wine bacteria and Oenococcus oeni X(2)L, an amensalistic growth response of the malolactic bacteria was produced due to a competition for nitrogenous nutrients, mainly peptides. Arginine was fully consumed and peptide concentration diminished 60% with respect to both pure cultures at the end of exponential growth. Histamine release increased 34% with respect to L.

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.

Influence of wine-related physicochemical factors on the growth and metabolism of non-Saccharomyces and Saccharomyces yeasts in mixed culture.

The influence of two physicochemical factors involved in winemaking, temperature and SO(2), on the kinetics and metabolic behavior of Kloeckera apiculata and Saccharomyces cerevisiae was examined. Highest biomass was reached at 15 and 25 degrees C for K. apiculata and S.

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.

Modification by glucose of the flocculent phenotype of a Kloeckera apiculata wine strain.

We have evaluated the induction of the flocculent phenotype of Kloeckera apiculata by glucose mc1 and propose a pathway involved in carbohydrate flocculation induction. Pulses of glucose were given to cells growing in glucose-poor medium (2 g l(-1)) and the flocculation percentage was measured. To elucidate the mechanism involved in flocculation induction, cycloheximide was injected into the cultures 120 min before the glucose pulse.

Improvement of a chemically defined medium for the sustained growth of Lactobacillus plantarum: nutritional requirements.

The aims of this work were to improve a basal synthetic medium (BM) for the growth of Lactobacillus plantarum strains and to establish their amino-acid requirements. Amino-acid use was analyzed in the most nutritionally demanding bacterium. First, the improved BM (L.

Kinetics and metabolic behavior of a composite culture of Kloeckera apiculata and Saccharomyces cerevisiae wine related strains.

The kinetics and metabolic behavior of Kloeckera apiculata mc1 and Saccharomyces cerevisiae mc2 in composite culture was investigated. K. apiculata showed a higher viability through the fermentation; however the maximum cell density of both yeasts decreased.

Growth response and modifications of organic nitrogen compounds in pure and mixed cultures of lactic acid bacteria from wine.

The interactions between the proteolytic X2L strain of Oenococcus oeni and the non-proteolytic 12p strain of Pediococcus pentosaceus were assayed. The characteristics of cell growth, protein degradation, and amino acid production of both strains were determined in pure and mixed cultures. O.

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.

Differences between biogenic amine detection by HPLC methods using OPA and dansyl derivates.

Biogenic amines can be formed and degraded as a result of normal metabolic activity in animals, plants, and microorganisms and are usually produced by the decarboxylation of amino acids. Recent trends in food security are promoting an increasing search for trace compounds that can affect human health. Although they are present in fermented foods and beverages in low quantities, they exhibit interactions with normal human metabolism (e.

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.