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).This work was performed with the financial support of the Spanish Ministry of Economy and Competitiveness (AGL2013-45431-R) and the Plan for Science, Technology and Innovation 2013–2017 of the Principality of Asturias, which is co-funded by the European Regional Development Fund (GRUPIN14-137).Peer reviewe

The tyrosyl-tRNA synthetase like gene located in the tyramine biosynthesis cluster of Enterococcus durans is transcriptionally regulated by tyrosine concentration and extracellular pH

<p>Abstract</p> <p>Background</p> <p>The tyramine producer <it>Enterococcus durans </it>IPLA655 contains all the necessary genes for tyramine biosynthesis, grouped in the TDC cluster. This cluster includes <it>tyrS</it>, an aminoacyl-tRNA synthetase like gene.</p> <p>Results</p> <p>This work shows that <it>tyrS </it>was maximally transcribed in absence of tyrosine at acidic pH, showing a greater than 10-fold induction in mRNA levels over levels occurring in presence of tyrosine. Mapping of the <it>tyrS </it>transcriptional start site revealed an unusually long untranslated leader region of 322 bp, which displays the typical features of the T box transcriptional attenuation mechanism. The tyrosine concentration regulation of <it>tyrS </it>was found to be mediated by a transcription antitermination system, whereas the specific induction at acidic pH was regulated at transcription initiation level.</p> <p>Conclusions</p> <p>The expression of the <it>tyrS </it>gene present in the TDC cluster of <it>E. durans </it>is transcriptionally regulated by tyrosine concentration and extracelular pH. The regulation is mediated by both an antitermination system and the promoter itself.</p

Bacteriophages in Dairy Industry: PCR Methods as Valuable Tools

Under CC BY 3.0 license. © The Author(s).Microorganisms have been empirically used since ancestral times to produce fermented dairy products from milk. In the actual dair y industry, milk is subjected to large scale fermentation processes that involve microorgan isms mostly belonging to the Lactic Acid Bacteria (LAB) group. Bacteriophages that in fect LAB have been claimed as one of the principal sources of fermentation failure (spo ilage or delay) on the manufacture of many dairy products (Brüssow et al., 1998; Josephsen & Neve, 1998; Garneau & Moineau, 2011). Some estimates assume that virulent phages are the primary direct responsible of the largest-economic loss of dairy factories, since th ey affect negatively up to the 10% of all milk fermentations (Moineau & Levesque, 2005).This work was performed with financial support from the Ministry of Science and Innovation, Spain (AGL2010- 18430). B. del Río an d N. Martínez are beneficiary of a JAE DOC-CSIC contract (Spain). D. M. Linares is beneficiary of a FICYT contract (Asturias, Spain).Peer Reviewe

Mastitis modifies the biogenic amines profile in human milk, with significant changes in the presence of histamine, putrescine and spermine

Biogenic amines (BAs) are low molecular weight nitrogenous organic compounds with different biological activities. Putrescine, spermidine and spermine are essential for the development of the gut and immune system of newborns, and are all found in human milk. Little is known, however, about the role of histamine, tyramine or cadaverine in breast milk. Nor is it known whether mastitis alters the BA composition of milk. The BA profile of human milk, and the influence of mastitis on BA concentrations, were therefore investigated. Putrescine, spermidine and spermine were the main BAs detected. In mastitis-affected milk, the concentrations of putrescine, spermine and histamine were higher.This work was performed with the financial support of the Spanish Ministry of Economy and Competitiveness (AGL2013-45431-R and AGL2013-41980P) and the GRUPIN14-137 project (which is co-financed by the Plan for Science, Technology and Innovation of the Principality of Asturias 2014-2017 and the European Regional Development Funds). M.P. was the recipient of an FPU (Programa de Formacion del Profesorado Universitario) fellowship from the Spanish Ministry of Education, Culture and Sport.Peer Reviewe

Tyramine biosynthesis is transcriptionally induced at low pH and improves the fitness of Enterococcus faecalis in acidic environments

© 2014, Springer-Verlag Berlin Heidelberg. Enterococcus faecalis is a commensal bacterium of the human gut that requires the ability to pass through the stomach and therefore cope with low pH. E. faecalis has also been identified as one of the major tyramine producers in fermented food products, where they also encounter acidic environments. In the present work, we have constructed a non-tyramine-producing mutant to study the role of the tyramine biosynthetic pathway, which converts tyrosine to tyramine via amino acid decarboxylation. Wild-type strain showed higher survival in a system that mimics gastrointestinal stress, indicating that the tyramine biosynthetic pathway has a role in acid resistance. Transcriptional analyses of the E. faecalis V583 tyrosine decarboxylase cluster showed that an acidic pH, together with substrate availability, induces its expression and therefore the production of tyramine. The protective role of the tyramine pathway under acidic conditions appears to be exerted through the maintenance of the cytosolic pH. Tyramine production should be considered important in the adaptability of E. faecalis to acidic environments, such as fermented dairy foods, and to survive passage through the human gastrointestinal tract.This work was funded by the Ministry of Economy and Competitiveness, Spain (AGL2013-45431-R) and the Spanish National Research Council (CSIC201270E144). M.P. is beneficiary of an FPU fellowship from the Spanish Ministry of Education.Peer Reviewe

Biofilm-forming capacity in biogenic amine-producing bacteria isolated from dairy products

Biofilms on the surface of food industry equipment are reservoirs of potentially food-contaminating bacteria-both spoilage and pathogenic. However, the capacity of biogenic amine (BA)-producers to form biofilms has remained largely unexamined. BAs are low molecular weight, biologically active compounds that in food can reach concentrations high enough to be a toxicological hazard. Fermented foods, especially some types of cheese, accumulate the highest BA concentrations of all. The present work examines the biofilm-forming capacity of 56 BA-producing strains belonging to three genera and 10 species (12 Enterococcus faecalis, 6 Enterococcus faecium, 6 Enterococcus durans, 1 Enterococcus hirae, 12 Lactococcus lactis, 7 Lactobacillus vaginalis, 2 Lactobacillus curvatus, 2 Lactobacillus brevis, 1 Lactobacillus reuteri, and 7 Lactobacillus parabuchneri), all isolated from dairy products. Strains of all the tested species - except for L. vaginalis-were able to produce biofilms on polystyrene and adhered to stainless steel. However, the biomass produced in biofilms was strain-dependent. These results suggest that biofilms may provide a route via which fermented foods can become contaminated by BA-producing microorganisms.This work was funded by the Spanish Ministry of the Economy and Competitiveness (AGL2013-45431-R) and the Plan for Science, Technology and Innovation 2013–2017 financed by the European Regional Development Fund and the Principality of Asturias (GRUPIN14-137). MD is a beneficiary of an FPI fellowship from the Spanish Ministry of the Economy and Competitiveness.Peer Reviewe

Comparative analysis of the in vitro cytotoxicity of the dietary biogenic amines tyramine and histamine

Tyramine and histamine, the most toxic biogenic amines (BA), are often found in high concentrations in certain foods. Prompted by the limited knowledge of BA toxicity, and increasing awareness of the risks associated with high intakes of dietary BA, the in vitro cytotoxicity of tyramine and histamine was investigated. Tyramine and histamine were toxic for HT29 intestinal cell cultures at concentrations commonly found in BA-rich food, as determined by real-time cell analysis. Surprisingly, tyramine had a stronger and more rapid cytotoxic effect than histamine. Their mode of action was also different, while tyramine caused cell necrosis, histamine induced apoptosis. To avoid health risks, the BA content of foods should be reduced and legal limits established for tyramine.This work was funded by the Spanish Ministry of Economy and Competitiveness (AGL2013-45431-R) and by the GRUPIN14-137 project, which is co-financed by the Plan for Science, Technology and Innovation of the Principality of Asturias 2014-2017 and the European Regional Development Funds.Peer reviewe

Genetic and functional analysis of biogenic amine production capacity among starter and non-starter lactic acid bacteria isolated from artisanal cheeses

© 2015, Springer-Verlag Berlin Heidelberg. This work reports the capacity of 137 strains of starter and non-starter LAB belonging to nine species of the genera Lactobacillus, Lactococcus, Streptococcus and Leuconostoc (all isolated from artisanal cheeses) to produce histamine, tyramine, putrescine and β-phenylethylamine, the biogenic amines (BA) most commonly found in dairy products. Production assays were performed in liquid media supplemented with the appropriate precursor amino acid; culture supernatants were then tested for BA by (U)HPLC. In addition, the presence of key genes involved in the biosynthetic pathways of the target BA, including the production of putrescine via the agmatine deiminase pathway, was assessed by PCR. Twenty strains were shown to have genes involved in the synthesis of BA; these belonged to the species Lactobacillus brevis (4), Lactobacillus curvatus (3), Lactococcus lactis (11) and Streptococcus thermophilus (2). With the exception of the two S. thermophilus strains, all those possessing genes involved in BA production synthesized the corresponding compound. Remarkably, all the putrescine-producing strains used the agmatine deiminase pathway. Four L. brevis and two L. curvatus strains were found able to produce both tyramine and putrescine. There is increasing interest in the use of autochthonous LAB strains in starter and adjunct cultures for producing dairy products with ‘particular geographic indication’ status. Such strains should not produce BA; the present results show that BA production capacity should be checked by (U)HPLC and PCR.This work was funded by the Ministry of Economy and Competitiveness, Spain (AGL2013-45431-R), the Fundación para el Fomento en Asturias de la Investigación Científica Aplicada y la Tecnología (FICYT), cofunded by FEDER (GRUPIN14-137) and the INIA (RM2011-00005-00-00).Peer Reviewe