The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
W Zhou - One of the best experts on this subject based on the ideXlab platform.
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A newly isolated strain Pediococcus parvulus from Xuanwei ham, a traditional Chinese fermented meat product
International Journal of Food Science and Technology, 2008Co-Authors: Pinglan Li, Qingwu Shen, Peng Fu, W ZhouAbstract:Summary A comparative study on technological suitability for fermented dry sausages of Pediococcus parvulus, a newly isolated strain from Xuanwei ham, a traditional Chinese fermented meat product, was carried out. One type of fermented dry sausage was produced with P. parvulus and the other without starter culture, using the same formulation and technological conditions. Thus, the evolutions of microbiological and physicochemical parameters during ripening, as well as colour, texture and sensory quality of end products, were measured and assessed. The results indicated that P. parvulus had an inhibitory effect on non-lactic acid bacteria, especially Enterobacteriaceae. It was thought that the use of P. parvulus could enhance the hygienic quality of fermented sausages, which could mainly be attributed to its acidification of fermented sausages. Differences in colour parameters, with higher value in lightness (L*) and lower in redness (a*), were also found (P
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a newly isolated strain Pediococcus parvulus from xuanwei ham a traditional chinese fermented meat product
International Journal of Food Science and Technology, 2008Co-Authors: Qingwu Shen, Ziyu Liu, W ZhouAbstract:Summary A comparative study on technological suitability for fermented dry sausages of Pediococcus parvulus, a newly isolated strain from Xuanwei ham, a traditional Chinese fermented meat product, was carried out. One type of fermented dry sausage was produced with P. parvulus and the other without starter culture, using the same formulation and technological conditions. Thus, the evolutions of microbiological and physicochemical parameters during ripening, as well as colour, texture and sensory quality of end products, were measured and assessed. The results indicated that P. parvulus had an inhibitory effect on non-lactic acid bacteria, especially Enterobacteriaceae. It was thought that the use of P. parvulus could enhance the hygienic quality of fermented sausages, which could mainly be attributed to its acidification of fermented sausages. Differences in colour parameters, with higher value in lightness (L*) and lower in redness (a*), were also found (P < 0.05). The most significant differences were observed in texture, informing the influence of P. parvulus on texture profile analysis characteristics of fermented sausages (P < 0.05). However, the evolutions of total nitrogen, fat and ash were the same. That meant the starter had no effects on these parameters during ripening of sausages. Free amino acid analysis showed that P. parvulus might have some proteolytic activity and more intense odour detected by our sensory judges. Our panelists also gave a higher score to the sausage with starter in terms of overall acceptability, indicating their preference of this product to the control. For all these results, we concluded that the newly isolated strain P. parvulus was a good starter for the production of fermented sausages.
Eva Nordberg Karlsson - One of the best experts on this subject based on the ideXlab platform.
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Xylooligosaccharides from hardwood and cereal xylans produced by a thermostable xylanase as carbon sources for Lactobacillus brevis and Bifidobacterium adolescentis.
Journal of agricultural and food chemistry, 2013Co-Authors: Peter Falck, Suthsiri Precha-atsawanan, Carl Grey, Peter Immerzeel, Henrik Stålbrand, Patrick Adlercreutz, Eva Nordberg KarlssonAbstract:To compare xylans from forestry with agricultural origins, hardwood xylan (birch) and cereal arabinoxylan (rye) were hydrolyzed using two variants of the xylanase RmXyn10A, full-length enzyme and catalytic module only, from Rhodothermus marinus . Cultivations of four selected bacterial species, using the xylooligosaccharide (XOS) containing hydrolysates as carbon source, showed selective growth of Lactobacillus brevis DSMZ 1264 and Bifidobacterium adolescentis ATCC 15703. Both strains were confirmed to utilize the XOS fraction (DP 2-5), whereas putative arabinoxylooligosaccharides from the rye arabinoxylan hydrolysate were utilized by only B. adolescentis. Escherichia coli did not grow, despite its capability to grow on the monosaccharides arabinose and xylose. It was also shown that Pediococcus parvulus strain 2.6 utilized neither xylose nor XOS for growth. In summary, RmXyn10A or its catalytic module proved suitable for high-temperature hydrolysis of hardwood xylan and cereal arabinoxylan, producing XOS that could qualify as prebiotics for use in functional food products.
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Xylooligosaccharides from Hardwood and Cereal Xylans Produced by a Thermostable Xylanase as Carbon Sources for Lactobacillus brevis and Bifidobacterium adolescentis
2013Co-Authors: Peter Falck, Suthsiri Precha-atsawanan, Carl Grey, Peter Immerzeel, Patrick Adlercreutz, Henrik Stålbrand, Eva Nordberg KarlssonAbstract:To compare xylans from forestry with agricultural origins, hardwood xylan (birch) and cereal arabinoxylan (rye) were hydrolyzed using two variants of the xylanase RmXyn10A, full-length enzyme and catalytic module only, from Rhodothermus marinus. Cultivations of four selected bacterial species, using the xylooligosaccharide (XOS) containing hydrolysates as carbon source, showed selective growth of Lactobacillus brevis DSMZ 1264 and Bifidobacterium adolescentis ATCC 15703. Both strains were confirmed to utilize the XOS fraction (DP 2–5), whereas putative arabinoxylooligosaccharides from the rye arabinoxylan hydrolysate were utilized by only B. adolescentis. Escherichia coli did not grow, despite its capability to grow on the monosaccharides arabinose and xylose. It was also shown that Pediococcus parvulus strain 2.6 utilized neither xylose nor XOS for growth. In summary, RmXyn10A or its catalytic module proved suitable for high-temperature hydrolysis of hardwood xylan and cereal arabinoxylan, producing XOS that could qualify as prebiotics for use in functional food products
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Characterization of the properties of Pediococcus parvulus for probiotic or protective culture use.
Journal of food protection, 2010Co-Authors: Tina Immerstrand, Olle Holst, Rickard Öste, Catherine J. Paul, Anna Rosenquist, Sahar F. Deraz, Olof Mårtensson, Åsa Ljungh, Anna Blücher, Eva Nordberg KarlssonAbstract:Pediococcus parvulus 2.6 (previously Pediococcus damnosus 2.6, here confirmed as P. parvulus by 16S DNA sequencing) displayed antibacterial activity toward several bacterial species, including isolates found as contaminants in oats, herein genetically identified as Bacillus cereus. No inhibition of Listeria monocytogenes was found under the conditions used. Antibacterial activity was retrieved after ammonium sulfate or acetone precipitation showed it to be peptide mediated. P. parvulus 2.6 has previously shown good technological properties in oat-based products. This, together with the currently found inhibition of food spoilage microorganisms like B. cereus, makes it suitable as a food protective culture. Survival trials of P. parvulus 2.6 at conditions mimicking the gastrointestinal tract were prompted by previously found cholesterol-lowering effects in humans after consumption of oat products cofermented by using P. parvulus 2.6 and Bifidobacterium spp. Viability was measured with in vitro, gutlike simulations at 37 degrees C. High survival was shown under two of three conditions (gastric juice, bile, and small intestine juice), defined as main obstacles of the gastrointestinal tract. The critical step was bile exposure. At a concentration of 20%, viability was low, but 0.3% bile (mean concentration in the intestine) did not have a major influence on growth. Viability of P. parvulus 2.6 was significantly decreased in gastric juice at pH 1.5 (with pepsin), but it was not significantly affected at pH 2.5, and was also improved at a lower pH in 20% oat milk. Viability was judged sufficient for colonization at gutlike conditions, qualifying the strain for further probiotic studies.
Qingwu Shen - One of the best experts on this subject based on the ideXlab platform.
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A newly isolated strain Pediococcus parvulus from Xuanwei ham, a traditional Chinese fermented meat product
International Journal of Food Science and Technology, 2008Co-Authors: Pinglan Li, Qingwu Shen, Peng Fu, W ZhouAbstract:Summary A comparative study on technological suitability for fermented dry sausages of Pediococcus parvulus, a newly isolated strain from Xuanwei ham, a traditional Chinese fermented meat product, was carried out. One type of fermented dry sausage was produced with P. parvulus and the other without starter culture, using the same formulation and technological conditions. Thus, the evolutions of microbiological and physicochemical parameters during ripening, as well as colour, texture and sensory quality of end products, were measured and assessed. The results indicated that P. parvulus had an inhibitory effect on non-lactic acid bacteria, especially Enterobacteriaceae. It was thought that the use of P. parvulus could enhance the hygienic quality of fermented sausages, which could mainly be attributed to its acidification of fermented sausages. Differences in colour parameters, with higher value in lightness (L*) and lower in redness (a*), were also found (P
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a newly isolated strain Pediococcus parvulus from xuanwei ham a traditional chinese fermented meat product
International Journal of Food Science and Technology, 2008Co-Authors: Qingwu Shen, Ziyu Liu, W ZhouAbstract:Summary A comparative study on technological suitability for fermented dry sausages of Pediococcus parvulus, a newly isolated strain from Xuanwei ham, a traditional Chinese fermented meat product, was carried out. One type of fermented dry sausage was produced with P. parvulus and the other without starter culture, using the same formulation and technological conditions. Thus, the evolutions of microbiological and physicochemical parameters during ripening, as well as colour, texture and sensory quality of end products, were measured and assessed. The results indicated that P. parvulus had an inhibitory effect on non-lactic acid bacteria, especially Enterobacteriaceae. It was thought that the use of P. parvulus could enhance the hygienic quality of fermented sausages, which could mainly be attributed to its acidification of fermented sausages. Differences in colour parameters, with higher value in lightness (L*) and lower in redness (a*), were also found (P < 0.05). The most significant differences were observed in texture, informing the influence of P. parvulus on texture profile analysis characteristics of fermented sausages (P < 0.05). However, the evolutions of total nitrogen, fat and ash were the same. That meant the starter had no effects on these parameters during ripening of sausages. Free amino acid analysis showed that P. parvulus might have some proteolytic activity and more intense odour detected by our sensory judges. Our panelists also gave a higher score to the sausage with starter in terms of overall acceptability, indicating their preference of this product to the control. For all these results, we concluded that the newly isolated strain P. parvulus was a good starter for the production of fermented sausages.
Isabel Pardo - One of the best experts on this subject based on the ideXlab platform.
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influence of freezing temperatures prior to freeze drying on viability of yeasts and lactic acid bacteria isolated from wine
Journal of Applied Microbiology, 2017Co-Authors: Lucia Polo, Sergi Ferrer, Rosario Maneslazaro, I Olmeda, L E Cruzpio, Angel Medina, Isabel PardoAbstract:Aims To determine the effect of three different freezing temperatures on post-freeze-drying survival rates of wine yeasts and lactic acid bacteria (LAB). To know if a similar freeze-drying protocol can be used for both micro-organisms. Methods and Results Cells from liquid culture media were recovered and concentrated in appropriate lyoprotectants. Aliquots of each strain were frozen at −20, −80 and −196°C before vacuum drying. Viable cell counts were done before freezing and after freeze-drying. Survival rates were calculated. Freezing temperatures differently affected yeast and bacteria survival. The highest survival rates were obtained at −20 and −80°C for yeasts, but at −196°C for LAB. Major differences in survival rates were recorded among freeze-dried yeasts, but were less drastic for LAB. Yeasts Pichia membranifaciens, Starmerella bacillaris and Metschnikowia pulcherrima, and LAB Lactobacillus paracasei, Pediococcus parvulus and Lactobacillus mali, were the most tolerant species to freeze-drying, regardless of freezing temperature. Conclusions Yeast and LAB survival rates differed for each tested freezing temperature. For yeasts, −20°C ensured the highest post-freeze-drying viability and −196°C for LAB. Significance and Impact of the Study Freezing temperature to freeze-dry cells is a crucial factor for ensuring good wine yeast and LAB survival. These results are important for appropriately preserving micro-organisms and for improving starter production processes.
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Influence of freezing temperatures prior to freeze‐drying on viability of yeasts and lactic acid bacteria isolated from wine
Journal of applied microbiology, 2017Co-Authors: Lucia Polo, Sergi Ferrer, I Olmeda, Angel Medina, Rosario Mañes-lázaro, L.e. Cruz‐pio, Isabel PardoAbstract:Aims To determine the effect of three different freezing temperatures on post-freeze-drying survival rates of wine yeasts and lactic acid bacteria (LAB). To know if a similar freeze-drying protocol can be used for both micro-organisms. Methods and Results Cells from liquid culture media were recovered and concentrated in appropriate lyoprotectants. Aliquots of each strain were frozen at −20, −80 and −196°C before vacuum drying. Viable cell counts were done before freezing and after freeze-drying. Survival rates were calculated. Freezing temperatures differently affected yeast and bacteria survival. The highest survival rates were obtained at −20 and −80°C for yeasts, but at −196°C for LAB. Major differences in survival rates were recorded among freeze-dried yeasts, but were less drastic for LAB. Yeasts Pichia membranifaciens, Starmerella bacillaris and Metschnikowia pulcherrima, and LAB Lactobacillus paracasei, Pediococcus parvulus and Lactobacillus mali, were the most tolerant species to freeze-drying, regardless of freezing temperature. Conclusions Yeast and LAB survival rates differed for each tested freezing temperature. For yeasts, −20°C ensured the highest post-freeze-drying viability and −196°C for LAB. Significance and Impact of the Study Freezing temperature to freeze-dry cells is a crucial factor for ensuring good wine yeast and LAB survival. These results are important for appropriately preserving micro-organisms and for improving starter production processes.
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Regulation of hdc expression and HDC activity by enological factors in lactic acid bacteria
Journal of applied microbiology, 2008Co-Authors: José María Landete, Isabel Pardo, Sergi FerrerAbstract:Aims: The aim of this work was to study the influence of enological factors on the histidine decarboxylase gene (hdc) expression and on histidine decarboxylase enzyme (HDC) activity in Lactobacillus hilgardii, Pediococcus parvulus and Oenococcus oeni. Methods and Results: Cell extracts and whole cells were used. Glucose, fructose, malic acid and citric acid diminished the hdc expression. Ethanol did not increase hdc expression or activity in cells, but increased HDC activity. Temperature and pH had effect on the activity of HDC but not on hdc expression. Tartaric acid and l-lactic acid, and sulphur dioxide (SO2) had no effect on enzyme synthesis and activity. Bacterial species differ in the relative enzymatic activity but all the factors affected similarly to L. hilgardii, P. parvulus and O. oeni. Conclusions: The hdc gene expression was lowered by glucose, fructose, malic acid, and citric acid, whereas ethanol enhanced the HDC enzyme activity. The conditions that normally occur during malolactic fermentation and later on, could favour histamine production. SO2 could prevent bacterial growth, but does not diminish the HDC enzyme activity. Significance and Impact of the Study: Information on hdc expression and HDC activity can contribute to the prevention of histamine formation during wine production and storage.
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Which lactic acid bacteria are responsible for histamine production in wine
Journal of applied microbiology, 2005Co-Authors: José María Landete, Sergi Ferrer, Isabel PardoAbstract:Aims: To quantify the ability of 136 lactic acid bacteria (LAB), isolated from wine, to produce histamine and to identify the bacteria responsible for histamine production in wine. Methods and Results: A qualitative method based on pH changes in a plate assay was used to detect wine strains capable of producing high levels of histamine. Two quantitative, highly sensitive methods were used, an enzymatic method and HPLC, to quantify the histamine produced by LAB. Finally, an improved PCR test was carried out to detect the presence of histidine decarboxylase gene in these bacteria. The species exhibiting the highest frequency of histamine production is Oenococcus oeni. However, the concentration of histamine produced by this species is lower than that produced by strains belonging to species of Lactobacillus and Pediococcus. A correlation of 100% between presence of histidine decarboxylase gene and histamine production was observed. Wines containing histamine were analysed to isolate and characterize the LAB responsible for spoilage. Conclusions: Oenococcus was able to synthesize low concentrations of histamine in wines, while Pediococcus parvulus and Lactobacillus hilgardii have been detected as spoilage, high histamine-producing bacteria in wines. Significance and Impact of the Study: Information regarding histamine-producing LAB isolated from wines can contribute to prevent histamine formation during winemaking and storage.
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16s ardra a tool for identification of lactic acid bacteria isolated from grape must and wine
Systematic and Applied Microbiology, 2003Co-Authors: Ana Maria Rodas, Sergi Ferrer, Isabel PardoAbstract:Summary Lactic acid bacteria (LAB) are found in a great variety of habitats, including grape must and wines. There is a close relationship between the species of LAB which develop during fermentation and the eventual quality of the wine. For these reasons analytical techniques allowing fast and reliable identification of wine LAB are needed. In this work a simple and accurate protocol for identifying species of LAB isolated from grape must and wine is presented. This protocol is based on the amplification, directly from colony, of 16S rDNA and later digestion with one of the following restriction enzymes Bfa I, Mse I and Alu I. A sequential use of the three enzymes is proposed to simplify LAB wine identification, first Mse I, then Bfa I and finally, if necessary, Alu I digestion. The technique was able to discriminate 32 of the 36 LAB reference species tested and allowed the identification of 342 isolates from musts and wines. The isolates belonged to the species: Lactobacillus brevis, L. collinoides, L. coryniformis, L. hilgardii, L. mali, L. paracasei, Leuconostoc mesenteroides, Oenococcus oeni, Pediococcus parvulus and P. pentosaceus.
Paloma López - One of the best experts on this subject based on the ideXlab platform.
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evaluation of an o2 substituted 1 3 β d glucan produced by Pediococcus parvulus 2 6 in ex vivo models of crohn s disease
Frontiers in Microbiology, 2021Co-Authors: Sara Notararigo, E Varela, Anna Otal, Ivan Cristobo, Maria Antolin, Francisco Guarner, Alicia Prieto, Paloma LópezAbstract:1,3-β-glucans are extracellular polysaccharides synthesized by microorganisms and plants, with therapeutic potential. Among them, the O2-substituted-(1-3)-β-D-glucan, synthesized by some lactic acid bacteria (LAB), has a prebiotic effect on probiotic strains, an immunomodulatory effect on monocyte-derived macrophages, and potentiates the ability of the producer strain to adhere to Caco-2 cells differentiated to enterocytes. In this work, the O2-substituted-(1-3)-β-D-glucan polymers produced by GTF glycoyltransferase in the natural host Pediococcus parvulus 2.6 and in the recombinant strain Lactococcus lactis NZ9000[pNGTF] were tested. Their immunomodulatory activity was investigated in an ex vivo model using human biopsies from patients affected by Crohn's disease (CD). Both polymers had an anti-inflammatory effect including, a reduction of Interleukine 8 both at the level of its gene expression and its secreted levels. The overall data indicate that the O2-substituted-(1-3)-β-D-glucan have a potential role in ameliorating inflammation via the gut immune system cell modulation.
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β-Glucan-Producing Pediococcus parvulus 2.6: Test of Probiotic and Immunomodulatory Properties in Zebrafish Models
Frontiers Media S.A., 2018Co-Authors: Adrián Pérez-ramos, Maria L. Mohedano, Miguel Á. Pardo, Paloma LópezAbstract:Lactic acid bacteria synthesize exopolysaccharides (EPS), which could benefit the host’s health as immunomodulators. Furthermore, EPS could protect bacteria against gastrointestinal stress, favoring gut colonization, thus protecting the host against pathogenic infections. Pediococcus parvulus 2.6, produces a 2-substituted (1,3)-β-D-glucan and, in this work, its probiotic properties as well as the immunomodulatory capability of its EPS have been investigated using Danio rerio (zebrafish). To this end and for a comparative analysis, P. parvulus 2.6 and its isogenic β-glucan-non-producing 2.6NR strain were fluorescently labeled by transfer of the pRCR12 plasmid, which encodes the mCherry protein. For the in vivo studies, there were used: (i) a gnotobiotic larvae zebrafish model for bacterial colonization, pathogen competition, and evaluation of the β-glucan immunomodulation capability and (ii) a transgenic (mpx:GFP) zebrafish model to determine the EPS influence in the recruitment of neutrophils under an induced inflammation. The results revealed a positive effect of the β-glucan on colonization of the zebrafish gut by P. parvulus, as well as in competition of the bacterium with the pathogen Vibrio anguillarum in this environment. The larvae treatment with the purified β-glucan resulted in a decrease of expression of genes encoding pro-inflammatory cytokines. Moreover, the β-glucan had an anti-inflammatory effect, when it was evaluated in an induced inflammation model of Tg(mpx:GFP) zebrafish. Therefore, P. parvulus 2.6 and its EPS showed positive health properties in in vivo fish models, supporting their potential usage in aquaculture
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Data_Sheet_1_β-Glucan-Producing Pediococcus parvulus 2.6: Test of Probiotic and Immunomodulatory Properties in Zebrafish Models.PDF
2018Co-Authors: Adrián Pérez-ramos, Maria L. Mohedano, Miguel Á. Pardo, Paloma LópezAbstract:Lactic acid bacteria synthesize exopolysaccharides (EPS), which could benefit the host’s health as immunomodulators. Furthermore, EPS could protect bacteria against gastrointestinal stress, favoring gut colonization, thus protecting the host against pathogenic infections. Pediococcus parvulus 2.6, produces a 2-substituted (1,3)-β-D-glucan and, in this work, its probiotic properties as well as the immunomodulatory capability of its EPS have been investigated using Danio rerio (zebrafish). To this end and for a comparative analysis, P. parvulus 2.6 and its isogenic β-glucan-non-producing 2.6NR strain were fluorescently labeled by transfer of the pRCR12 plasmid, which encodes the mCherry protein. For the in vivo studies, there were used: (i) a gnotobiotic larvae zebrafish model for bacterial colonization, pathogen competition, and evaluation of the β-glucan immunomodulation capability and (ii) a transgenic (mpx:GFP) zebrafish model to determine the EPS influence in the recruitment of neutrophils under an induced inflammation. The results revealed a positive effect of the β-glucan on colonization of the zebrafish gut by P. parvulus, as well as in competition of the bacterium with the pathogen Vibrio anguillarum in this environment. The larvae treatment with the purified β-glucan resulted in a decrease of expression of genes encoding pro-inflammatory cytokines. Moreover, the β-glucan had an anti-inflammatory effect, when it was evaluated in an induced inflammation model of Tg(mpx:GFP) zebrafish. Therefore, P. parvulus 2.6 and its EPS showed positive health properties in in vivo fish models, supporting their potential usage in aquaculture.
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characterization of the sorbitol utilization cluster of the probiotic Pediococcus parvulus 2 6 genetic functional and complementation studies in heterologous hosts
Frontiers in Microbiology, 2017Co-Authors: Adrian Perezramos, Giuseppe Spano, Maria Laura Werning, M.m.l. Mohedano, Alicia Prieto, Pasquale Russo, Paloma LópezAbstract:Pediococcus parvulus 2.6 secretes a 2-substituted (1,3)-β-D-glucan with prebiotic and immunomodulatory properties. It is synthesized by GTF glycosyltransferase using UDP-glucose as substrate. Analysis of the P. parvulus 2.6 draft genome revealed the existence of a sorbitol utilization cluster of six genes (gutFRMCBA), whose products should be involved in sorbitol utilization and could generate substrates for UDP-glucose synthesis. Southern blot hybridization analysis showed that the cluster is located in a plasmid. Analysis of metabolic fluxes and production of the exopolysaccharide revealed that: (i) P. parvulus 2.6 is able to metabolize sorbitol, (ii) sorbitol utilization is repressed in the presence of glucose and (iii) sorbitol supports the synthesis of 2-substituted (1,3)-β-D-glucan. The sorbitol cluster encodes two putative regulators, GutR and GutM, in addition to a phosphoenolpyruvate-dependent phosphotransferase transport system and sorbitol-6-phosphate dehydrogenase. Therefore, we investigated the involvement of GutR and GutM in the expression of gutFRMCBA. The promoter-probe vector pRCR based on the mrfp gene, which encodes the fluorescence protein mCherry, was used to test the potential promoter of the cluster (Pgut) and the genes encoding the regulators. This was performed by transferring by electrotransformation the recombinant plasmids into two hosts, which metabolize sorbitol: Lactobacillus plantarum and Lactobacillus casei. Upon growth in the presence of sorbitol, but not of glucose, only the presence of Pgut was required to support expression of mrfp in L. plantarum. In L. casei the presence of sorbitol in the growth medium and the pediococcal gutR or gutR plus gutM in the genome was required for Pgut functionality. This demonstrates that: (i) Pgut is required for expression of the gut cluster, (ii) Pgut is subjected to catabolic repression in lactobacilli, (iii) GutR is an activator, and (iv) in the presence of sorbitol, trans-complementation for activation of Pgut exists in L. plantarum but not in L. casei.
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in situ β glucan fortification of cereal based matrices by Pediococcus parvulus 2 6 technological aspects and prebiotic potential
International Journal of Molecular Sciences, 2017Co-Authors: Adrian Perezramos, Giuseppe Spano, Paloma López, Maria Luz Mohedano, Daniela Fiocco, Pasquale Russo, Vittorio CapozziAbstract:Bacterial exopolysaccharides produced by lactic acid bacteria are of increasing interest in the food industry, since they might enhance the technological and functional properties of some edible matrices. In this work, Pediococcus parvulus 2.6, which produces an O2-substituted (1,3)-β-d-glucan exopolysaccharide only synthesised by bacteria, was proposed as a starter culture for the production of three cereal-based fermented foods. The obtained fermented matrices were naturally bio-fortified in microbial β-glucans, and used to investigate the prebiotic potential of the bacterial exopolysaccharide by analysing the impact on the survival of a probiotic Lactobacillus plantarum strain under starvation and gastrointestinal simulated conditions. All of the assays were performed by using as control of the P. parvulus 2.6's performance, the isogenic β-glucan non-producing 2.6NR strain. Our results showed a differential capability of P. parvulus to ferment the cereal flours. During the fermentation step, the β-glucans produced were specifically quantified and their concentration correlated with an increased viscosity of the products. The survival of the model probiotic L. plantarum WCFS1 was improved by the presence of the bacterial β-glucans in oat and rice fermented foods under starvation conditions. The probiotic bacteria showed a significantly higher viability when submitted to a simulated intestinal stress in the oat matrix fermented by the 2.6 strain. Therefore, the cereal flours were a suitable substrate for in situ bio-fortification with the bacterial β-glucan, and these matrices could be used as carriers to enhance the beneficial properties of probiotic bacteria.