Tryptamine accumulates in cheese mainly via the decarboxylation of tryptophan by lactic acid bacteria.

Few microorganisms are known to decarboxylate L-tryptophan, thereby producing tryptamine, a neuromodulator biogenic amine (BA) that can accumulate in cheese. Since lactic acid bacteria (LAB) are largely responsible for the production of other BA in this product, it was hypothesised that they would also be the main agents of tryptamine production. Using a rapid test based on the natural fluorescence of tryptamine, thousands of bacterial isolates from several cheese samples were screened.

Do the biogenic amines ethylamine, ethanolamine and methylamine reach toxic concentrations in foods?

Ethylamine, ethanolamine and methylamine are biogenic amines (BA) - active metabolites that, despite having important biological functions, may accumulate at toxic concentrations in certain foods. Very little information exists on the toxicity of these BA in this context. This study provides new insights into their cytotoxicity with respect to a human intestinal epithelial cell line, as assessed using real-time cell analyzer technology.

Identification of technological/metabolic/environmental profiles associated with cheeses accumulating the neuroactive compound tryptamine.

Tryptamine is a neuromodulator of the central nervous system. It is also a biogenic amine, formed by the microbial decarboxylation of L-tryptophan. Tryptamine accumulation in cheese has been scarcely examined.

Brazilian indigenous nonstarter lactic acid bacteria enhance the diversification of volatile compounds in short-aged cheese.

There is growing interest in using autochthonous lactic acid bacteria (LAB) that provide unique sensory characteristics to dairy products without affecting their safety and quality. This work studied the capacity of three Brazilian indigenous nonstarter LABs (NSLAB) to produce biogenic amines (BAs) and evaluated their effect on the volatile organic compounds (VOCs), microbial LAB communities, and physicochemical profile of short-aged cheese. Initially, the strain's potential for biosynthesis of BAs was assessed by PCR and in vitro assays.

New insights into the toxicological effects of dietary biogenic amines.

Biogenic amines (BA) are molecules with biological functions, which can accumulate at toxic concentrations in foods. Several microorganisms have been identified as responsible for their accumulation at elevated concentrations. Histamine, tyramine and putrescine are the BA most commonly found at highest concentrations.

An Overview on Fecal Profiles of Amino Acids and Related Amino-Derived Compounds in Children with Autism Spectrum Disorder in Tunisia.

Autism spectrum disorder (ASD) is a neurodevelopmental pathology characterized by the impairment of social interaction, difficulties in communication, and repetitive behaviors. Alterations in the metabolism of amino acids have been reported. We performed a chromatographic analysis of fecal amino acids, ammonium, biogenic amines, and gamma aminobutyric acid (GABA) in Tunisian autistic children from 4 to 10 years, and results were compared with their siblings (SIB) and children from the general population (GP).

Fecal Metabolome and Bacterial Composition in Severe Obesity: Impact of Diet and Bariatric Surgery.

The aim of this study was to monitor the impact of a preoperative low-calorie diet and bariatric surgery on the bacterial gut microbiota composition and functionality in severe obesity and to compare sleeve gastrectomy (SG) Roux-en-Y gastric bypass (RYGB). The study also aimed to incorporate big data analysis for the omics results and machine learning by a Lasso-based analysis to detect the potential markers for excess weight loss. Forty patients who underwent bariatric surgery were recruited (14 underwent SG, and 26 underwent RYGB).

Investigating the biotechnological potential of lactic acid bacteria strains isolated from different Algerian dairy and farm sources.

Currently, consumption of spontaneously fermented milks is common in Algeria, making it a feasible source of diverse lactic acid bacteria (LAB) with the potential to be used as adjunct cultures to improve quality and safety of fermented dairy products. In this context, to select eligible indigenous strains which could be applied as bioprotective and/or starter cultures, the present study aimed to characterize the genomic variability, biotechnological potential, and safety of thirty-eight LAB isolated from Algerian dairy and farm sources of western Algeria. The isolates were unequivocally identified by 16S rRNA gene and fingerprint-based methods.

GABA-Producing Strains Isolated from Camel's Milk as Starters for the Production of GABA-Enriched Cheese.

The multiple health benefits attributed to the bioactive compound γ-aminobutyric acid (GABA) have prompted the food industry to investigate the development of functional GABA-rich foods via the use of GABA-producing microorganisms. This study reports the isolation of six GABA-producing strains from camel's milk; this is the first time that such microorganisms have been isolated from milk. The sequencing and analysis of their genomes, and the characterisation of their technological and safety properties, confirmed their potential as starters.

Polyphasic Characterisation of Non-Starter Lactic Acid Bacteria from Algerian Raw Camel's Milk and Their Technological Aptitudes.

Research Background: Consumption of spontaneously fermented camel´s milk is common in Algeria, making it a feasible source of diverse lactic acid bacteria (LAB) with the potential to be used as adjunct cultures to improve quality and safety of fermented dairy products.

Experimental Approach: Twelve raw camel´s milk samples were used as a source of indigenous LAB, which were further characterised by examining39 phenotypic traits with technological relevance.

Results And Conclusions: Thirty-five non-starter LAB (NSLAB) were isolated from 12 Algerian raw camel's milk samples and they were microbiologically, biochemically and genetically characterised.

Metabolism of Soy Isoflavones by Intestinal Bacteria: Genome Analysis of an Strain That Does Not Produce Equol.

Isoflavones are transformed in the gut into more estrogen-like compounds or into inactive molecules. However, neither the intestinal microbes nor the pathways leading to the synthesis of isoflavone-derived metabolites are fully known. In the present work, 73 fecal isolates from three women with an equol-producing phenotype were considered to harbor equol-related genes by qPCR.

The biogenic amine tryptamine, unlike β-phenylethylamine, shows in vitro cytotoxicity at concentrations that have been found in foods.

β-phenylethylamine and tryptamine are biogenic amines (BA) often found in foods. In general, BA are assumed to be toxic and their accumulation in food is not recommended. However, present knowledge regarding the toxicity of β-phenylethylamine and tryptamine is limited; more information is needed if qualitative and quantitative risk assessments of foods are to be successfully conducted.

Histamine production in Lactobacillus vaginalis improves cell survival at low pH by counteracting the acidification of the cytosol.

Histamine, one of the most toxic and commonly encountered biogenic amines (BA) in food, is produced by the microbial decarboxylation of histidine. It may accumulate at high concentrations in fish and fermented food. Cheese has some of the highest histamine concentrations, the result of the histidine-decarboxylase activity of certain lactic acid bacteria (LAB).

Construction and characterization of a double mutant of Enterococcus faecalis that does not produce biogenic amines.

Enterococcus faecalis is a lactic acid bacterium characterized by its tolerance of very diverse environmental conditions, a property that allows it to colonize many different habitats. This species can be found in food products, especially in fermented foods where it plays an important role as a biopreservative and influences the development of organoleptic characteristics. However, E.

Transcriptional Regulation of the Equol Biosynthesis Gene Cluster in DSM19450.

Given the emerging evidence of equol's benefit to human health, understanding its synthesis and regulation in equol-producing bacteria is of paramount importance. DSM19450 is a human intestinal bacterium -for which the whole genome sequence is publicly available- that produces equol from the daidzein isoflavone. In the present work, daidzein (between 50 to 200 μM) was completely metabolized by cultures of DSM19450 after 10 h of incubation.

Bacteriophage 156 Is an Effective Biotechnological Tool for Reducing the Presence of Tyramine and Putrescine in an Experimental Cheese Model.

Biogenic amines (BA) - nitrogenous compounds of low molecular weight - are the result of metabolism of certain amino acids. They are biologically present in all living organisms and play essential physiological roles. However, their accumulation in foodstuffs due to the metabolic activity of certain microorganisms represents a toxicological risk.

The biogenic amines putrescine and cadaverine show in vitro cytotoxicity at concentrations that can be found in foods.

Putrescine and cadaverine are among the most common biogenic amines (BA) in foods, but it is advisable that their accumulation be avoided. Present knowledge about their toxicity is, however, limited; further research is needed if qualitative and quantitative risk assessments for foods are to be conducted. The present work describes a real-time analysis of the cytotoxicity of putrescine and cadaverine on intestinal cell cultures.

Putrescine biosynthesis and export genes are essential for normal growth of avian pathogenic Escherichia coli.

Background: Avian pathogenic Escherichia coli (APEC) is the infectious agent of a wide variety of avian diseases, which causes substantial economic losses to the poultry industry worldwide. Polyamines contribute to the optimal synthesis of nucleic acids and proteins in bacteria. The objectives of this study were to investigate; i) whether APEC E.

An altered gene expression profile in tyramine-exposed intestinal cell cultures supports the genotoxicity of this biogenic amine at dietary concentrations.

Tyramine, histamine and putrescine are the most commonly detected and most abundant biogenic amines (BA) in food. The consumption of food with high concentrations of these BA is discouraged by the main food safety agencies, but legal limits have only been set for histamine. The present work reports a transcriptomic investigation of the oncogenic potential of the above-mentioned BA, as assessed in the HT29 human intestinal epithelial cell line.

Spermine and spermidine are cytotoxic towards intestinal cell cultures, but are they a health hazard at concentrations found in foods?

Spermine and spermidine are polyamines (PA) naturally present in all organisms, in which they have important physiological functions. However, an excess of PA has been associated with health risks. PA accumulates at quite high concentrations in some foods, but a quantitative assessment of the risk they pose has been lacking.

Lactobacillus rossiae strain isolated from sourdough produces putrescine from arginine.

This work reports a Lactobacillus rossiae strain (L. rossiae D87) isolated from sourdough that synthesizes putrescine - a biogenic amine that raises food safety and spoilage concerns - from arginine via the ornithine decarboxylase (ODC) pathway. The odc and potE genes were identified and sequenced.

The Relationship among Tyrosine Decarboxylase and Agmatine Deiminase Pathways in .

Enterococci are considered mainly responsible for the undesirable accumulation of the biogenic amines tyramine and putrescine in cheeses. The biosynthesis of tyramine and putrescine has been described as a species trait in Tyramine is formed by the decarboxylation of the amino acid tyrosine, by the tyrosine decarboxylase (TDC) route encoded in the cluster. Putrescine is formed from agmatine by the agmatine deiminase (AGDI) pathway encoded in the cluster.

The dietary biogenic amines tyramine and histamine show synergistic toxicity towards intestinal cells in culture.

Tyramine and histamine are the biogenic amines (BA) most commonly found at high concentrations in food; they may even appear together at toxic concentrations. The present work examines, via real-time cell analysis, whether histamine and tyramine show synergistic toxicity towards intestinal cell cultures. Employing a constant equipotency ratio, their interaction was examined via the combination index (CI) method of Chou & Talalay.

Data on recovery of 21 amino acids, 9 biogenic amines and ammonium ions after spiking four different beers with five concentrations of these analytes.

A novel chromatographic method for the simultaneous analysis of nine biogenic amines, 21 amino acids and ammonium ions in beer has been recently described in "A UHPLC method for the simultaneous analysis of biogenic amines, amino acids and ammonium ions in beer" (Redruello et al., 2017) [1]. The present article provides recovery data of the 31 analytes after spiking four different beers with five concentrations of each analyte (15, 30, 60, 120 and 240 µM).

A UHPLC method for the simultaneous analysis of biogenic amines, amino acids and ammonium ions in beer.

This paper reports a novel UHPLC method for simultaneously quantifying nine biogenic amines, 21 amino acids, and ammonium ions, in beer. Precision values of standard curves slopes were lower than 3.4% and recovery was between 85% and 106%, indicating the absence of matrix effect.