Distribution and cellular localization of sea bream estrogen receptors in calcified tissues

In teleost fish, estradiol has been shown to induce calcium mobilization from internal stores, in particular the scales. In the present study, we have localized the estrogen receptor proteins (α, βa and βb) in the scales of juvenile and adult sea bream, using immunohistochemistry with ER isoform-specific antibodies. The ERs co-localized in cells of the scale posterior region that also expressed TRACP, the putative osteoclasts. These results suggest that the calcium mobilising action of estradiol on fish scales is via its direct action on osteoclasts.European Social Fund and National Funds under the project POCTI/CVT/39355/2001 from the Portuguese Foundation for Science and Technology (FCT). PP was funded by the FCT grant POCTI/SFRH/ BD/5198/2001. MDE was in receipt of a PRODEP grant, Programa de Desenvolvimento Educativo para Portugal (medida5/concurso 2/acção5.3/2001)info:eu-repo/semantics/publishedVersio

PTHrP-induced modifications of the sea bream (Sparus auratus) vertebral bone proteome

Endocrine factors play an essential role in the formation and turnover of the skeleton in vertebrates. In the present study sea bream vertebral bone transcripts for PTH1R and PTH3R were identified and the action of intermittent administration of parathyroid hormone related protein (PTHrP) on the proteome of vertebral bone was analysed. Treatment of immature sea bream (Sparus auratus, n = 6) for 5 days with homologous recombinant PTHrP(1–125; 150 ng/g body weight) modified bone metabolism and caused a significant (p < 0.05) reduction in both tartrate resistant acid phosphatase (TRACP) and alkaline phosphatase (ALP) in relation to control fish. However, the ratio of TRACP: ALP in PTHrP treated fish (1.3 to 2.2 cf. control) suggested it had an anabolic response. A sea bream vertebral bone proteome of 157 protein spots was generated and putative identity assigned to 118 (75.2%) proteins of which 72% had homology to proteins/transcripts from teleosts many of which have not previously been reported in teleost bone. Classification of bone proteins using gene ontology revealed those with protein or metal/ion (e.g., calcium, magnesium, zinc) binding (∼53%) activities were most abundant. The expression of eight proteins was significantly (p < 0.05) modified in the vertebra of PTHrP treated compared to control fish; three were up-regulated, betainehomocystein S-methyltransferase, glial fibrillary acidic protein, parvalbumin beta and five were down-regulated, annexin A5, apolipoprotein A1, myosin light chain 2, fast skeletal myosin light chain 3, troponin C. In conclusion, intermittent administration of PTHrP to sea bream is associated with an anabolic response in vertebral bone metabolism and modifies calcium binding proteins in the proteome

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

Cloning and expression of a codon-optimized gene encoding the infl uenza A virus nucleocapsid protein in Lactobacillus casei

Lactic acid bacteria (LAB) species are envisioned as promising vehicles for the mucosal delivery of therapeutic and prophylactic molecules, including the development of oral vaccines. In this study, we report on the expression of a synthetic nucleocapsid (NP) gene of infl uenza A virus in Lactobacillus casei. The NP gene was re-designed based on the tRNA pool and the codon usage preference of L. casei BL23. The codon-optimized NP gene was then cloned and expressed in L. casei RCEID02 under the control of a constitutive promoter, that of the lactate dehydrogenase (ldh) gene. The synthetic NP gene was further expressed in L. casei EM116 under the control of an inducible promoter, that of the structural gene of nisin (nisA) from Lactococcus lactis. Based on Western blot analysis, the specifi c protein band of NP, with a molecular mass of 56.0 kDa, was clearly detected in both expression systems. Thus, our study demonstrates the success of expressing a codon-optimized infl uenza A viral gene in L. casei. The suitability of the recombinant LAB strains for immunization purposes is currently under evaluation. [Int Microbiol 2013; 16(2):93-101]Keywords: Lactobacillus casei; lactic acid bacteria; infl uenza A virus; viral nucleocapsid proteins; heterologous expression; codon usag

Putrescine production by Lactococcus lactis subsp. cremoris CECT 8666 is reduced by NaCl via a decrease in bacterial growth and the repression of the genes involved in putrescine production

The reduction of NaCl in food is a public health priority; high NaCl intakes have been associated with serious health problems. However, it is reported that reducing the NaCl content of cheeses may lead to an increase in the content of biogenic amines (BAs). The present work examines the effect of NaCl on the accumulation of putrescine (one of the BAs often detected at high concentration in cheese) in experimental Cabrales-like cheeses containing Lactococcus lactis subsp. cremoris CECT 8666, a dairy strain that catabolises agmatine to putrescine via the agmatine deiminase (AGDI) pathway. The genes responsible for this pathway are grouped in the AGDI cluster. This comprises a regulatory gene (aguR) (transcribed independently), followed by the catabolic genes that together form an operon (aguBDAC). Reducing the NaCl concentration of the cheese led to increased putrescine accumulation. In contrast, increasing the NaCl concentration of both pH-uncontrolled and pH-controlled (pH 6) cultures of L. lactis subsp. cremoris CECT 8666 significantly inhibited its growth and the production of putrescine. Such production appeared to be inhibited via a reduction in the transcription of the aguBDAC operon; no effect on the transcription of aguR was recorded. The present results suggest that low-sodium cheeses are at risk of accumulating higher concentrations of putrescine.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 2013–2017 and the European Regional Development Funds.Peer reviewe

Aminas biógenas en alimentos: métodos moleculares para la detección e identificación de bacterias productoras

Biogenic amines are low molecular weight nitrogenous compounds with biological activity that are formed by decarboxylation of certain amino acids. Biogenic amines are present in all living organisms, in which they have important physiological functions. However, due to the metabolism of certain microorganisms, these compounds can accumulate in food at high concentrations, constituting a health risk for consumers. The presence of biogenic amine-producing microorganisms is the indispensable condition for the presence and further accumulation of biogenic amines in food. Because of this, several methods for the detection and identification of these biogenic amine-producing microorganisms have been developed. Among them, those based on culture independent techniques, such as the PCR, have several advantages such as their specificity, they are methods that are fast and easy to perform, and in many cases there is no need for pre-processing of food material which facilitates their incorporation at production plants. In this work, some available methods for the detection of biogenic amine-producing microorganisms are described, as well as their potential applications.Las aminas biógenas son compuestos nitrogenados de pequeño tamaño con actividad biológica que se forman por la descarboxilación enzimática de ciertos aminoácidos. Las aminas biógenas se encuentran presentes en todos los seres vivos, en los que participan en procesos biológicas de gran importancia. Sin em­bargo, debido al metabolismo de algunos microorganismos, estos compuestos se pueden acumular en alimentos en concentraciones elevadas, constituyendo un riesgo para la salud de los consumido­res. Para que las aminas biógenas alcancen estas concentraciones elevadas en los alimentos se requiere, como condición indispensa­ble, la presencia de microrganismos productores, por lo que se han desarrollado diferentes métodos para detectar la presencia de los mismos. Entre estos métodos, aquellos basados en técnicas inde­pendientes de cultivo, como la PCR, presentan ventajas como su gran especificidad, el hecho de ser rápidos y de fácil realización, y que en muchos casos ni siquiera es necesario un tratamiento previo de la muestra, lo que facilita su incorporación a las plantas de elabo­ración. En este trabajo se describen algunos de los métodos dispo­nibles en la actualidad para la detección de microorganismos pro­ductores de aminas biógenas, así como sus posibles aplicaciones

Different metabolic features 1 of Bacteroides fragilis growing in the presence of glucose and exopolysaccharides of bifidobacteria

Bacteroides is among the most abundant microorganism inhabiting the human intestine. They are saccharolytic bacteria able to use dietary or host-derived glycans as energy sources. Some Bacteroides fragilis strains contribute to the maturation of the immune system but it is also an opportunistic pathogen. The intestine is the habitat of most Bifidobacterium species, some of whose strains are considered probiotics. Bifidobacteria can synthesize exopolysaccharides (EPS), which are complex carbohydrates that may be available in the intestinal environment. We studied the metabolism of B. fragilis when an EPS preparation from bifidobacteria was added to the growth medium compared to its behavior with added glucose. 2D-DIGE coupled with the identification by MALDI-TOF/TOF evidenced proteins that were differentially produced when EPS was added. The results were supported by RT qPCR gene expression analysis. The intracellular and extracellular pattern of certain amino acids, the redox balance and the a-glucosidase activity were differently affected in EPS with respect to glucose. These results allowed us to hypothesize that three general main events, namely the activation of amino acids catabolism, enhancement of the transketolase reaction from the pentose-phosphate cycle, and activation of the succinate-propionate pathway, promote a shift of bacterial metabolism rendering more reducing power and optimizing the energetic yield in the form of ATP when Bacteroides grow with added EPS. Our results expand the knowledge about the capacity of B. fragilis for adapting to complex carbohydrates and amino acids present in the intestinal environment. © 2015 Rios-covian, Sanchez, Salazar, Martinez, Redruello, Gueimonde and De los Reyes-Gavilan.This work was financed by projects AGL2010-16525 and AGL2013-43770-R from Plan Nacional/Plan Estatal de I+D+I (Spanish Ministry of Economy and Competitiveness, MINECO). The activity of Probiotics and Prebiotics Group is being partly supported through the Grant GRUPIN14-043 from Plan Regional de Investigación del Principado de Asturias. Both, national and regional grants received cofounding from European Union FEDER funds. DR-C was the recipient of predoctoral FPI fellowship whereas BS enjoys a Ramon and Cajal contract from MINECO. NS benefits from a Clarin post-doctoral contract (Marie Curie European CoFund Program) cofinanced by Plan Regional de Investigación del Principado de Asturias, Spain. We acknowledge the excellent technical assistance of Lidia Alaez, whose technician contract was partially supported by the project AGL2010-16525 and by Plan Regional de Investigación del Principado de Asturias, through the grant COF 13-020.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

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