Lactic Acid Bacteria Isolated from Fermented Doughs in Spain Produce Dextrans and Riboflavin

Many lactic acid bacteria (LAB) produce metabolites with applications in the food industry, such as dextran-type exopolysaccharides (EPS) and riboflavin (vitamin B2). Here, 72 bacteria were isolated from sourdoughs made by Spanish bread-makers. In the presence of sucrose, colonies of 22 isolates showed a ropy phenotype, and NMR analysis of their EPS supported that 21 of them were dextran producers. These isolates were identified by their random amplified polymorphic DNA (RAPD) patterns and their rrs and pheS gene sequences as LAB belonging to four species (Weissella cibaria, Leuconostoc citreum, Leuconostoc falkenbergense and Leuconostoc mesenteroides). Six selected strains from the Leuconostoc (3) and Weissella (3) genera grew in the absence of riboflavin and synthesized vitamin B2. The EPS produced by these strains were characterized as dextrans by physicochemical analysis, and the L. citreum polymer showed an unusually high degree of branching. Quantification of the riboflavin and the EPS productions showed that the W. cibaria strains produce the highest levels (585–685 μg/and 6.5–7.4 g/L, respectively). Therefore, these new LAB strains would be good candidates for the development of fermented foods bio-fortified with both dextrans and riboflavin. Moreover, this is the first report of riboflavin and dextran production by L. falkenbergense.This research was funded by the Spanish Ministry of Science, Innovation and Universities, (grants RTI2018-097114-B-I00 and PCIN-2017-075), by the Basque Government Industry and Education Department (grant PIBA_2020_1_0032) and by the University of the Basque Country (General Grant to Research Groups (GIU 19/014))

Lactic Acid Bacteria Isolated from Fermented Doughs in Spain Produce Dextrans and Riboflavin

Many lactic acid bacteria (LAB) produce metabolites with applications in the food industry, such as dextran-type exopolysaccharides (EPS) and riboflavin (vitamin B2). Here, 72 bacteria were isolated from sourdoughs made by Spanish bread-makers. In the presence of sucrose, colonies of 22 isolates showed a ropy phenotype, and NMR analysis of their EPS supported that 21 of them were dextran producers. These isolates were identified by their random amplified polymorphic DNA (RAPD) patterns and their rrs and pheS gene sequences as LAB belonging to four species (Weissella cibaria, Leuconostoc citreum, Leuconostoc falkenbergense and Leuconostoc mesenteroides). Six selected strains from the Leuconostoc (3) and Weissella (3) genera grew in the absence of riboflavin and synthesized vitamin B2. The EPS produced by these strains were characterized as dextrans by physicochemical analysis, and the L. citreum polymer showed an unusually high degree of branching. Quantification of the riboflavin and the EPS productions showed that the W. cibaria strains produce the highest levels (585–685 μg/and 6.5–7.4 g/L, respectively). Therefore, these new LAB strains would be good candidates for the development of fermented foods bio-fortified with both dextrans and riboflavin. Moreover, this is the first report of riboflavin and dextran production by L. falkenbergense.This research was funded by the Spanish Ministry of Science, Innovation and Universities, (grants RTI2018-097114-B-I00 and PCIN-2017-075), by the Basque Government Industry and Education Department (grant PIBA_2020_1_0032) and by the University of the Basque Country (General Grant to Research Groups (GIU 19/014))

A partial proteome reference map of the wine lactic acid bacterium Oenococcus oeni ATCC BAA-1163

Oenococcus oeni is the main lactic acid bacterium that carries out the malolactic fermentation in virtually all red wines and in some white and sparkling wines. Oenococcus oeni possesses an array of metabolic activities that can modify the taste and aromatic properties of wine. There is, therefore, industrial interest in the proteins involved in these metabolic pathways and related transport systems of this bacterium. In this work, we report the characterization of the O. oeni ATCC BAA-1163 proteome. Total and membrane protein preparations from O. oeni were standardized and analysed by two-dimensional gel electrophoresis. Using tandem mass spectrometry, we identified 224 different spots corresponding to 152 unique proteins, which have been classified by their putative function and subjected to bioinformatics analysis

Probiotic properties of EPS-producing Pediococcus strains

3 p.International Symposium on Immunonutrition 2017 Madrid, 17th–19th July, 2017 10th AnniversaryA. Pérez-Ramos was supported by the FPI grant BES-2013-065157 from the Spanish Ministry of Economy and Competitiveness. M.G. Llamas is recipient of a grant of the Basque Country Government for junior researchers in the scientific-technological environment of the fish farming and food basque sector. This work was supported by the Spanish Ministry of Economy and Competitiveness (grants AGL2012- 40084-C03 and AGL2015-65010-C3-1-R).Peer reviewe

Mídia Ninja, mídia tradicional e accountability

Created in 2011, the alternative mediatic group "Mídia Ninja" gained more visibility in June this year, covering and participating in marches and outdoor demonstrations in Brazil. Their streaming recordings were aired live and mostly uninterruptedly via internet, generating a large audience. As a consequence, those images and their impact ended up guiding the mainstream press and were responsible for some of the shifts of mainstream media framing about the fact. The alternativa media nourish itself from and at the same time, opposing the mainstream media. On the other hand, the mainstream media is guided by images the coverage of alternative media. Society has suspicions on the hegemonic discourse but also suspects the motives and funds of Mídia Ninja. In the midst of those issues, can we ask who has the ultimate accountability?Surgido em 2011, o grupo Mídia Ninja ganhou mais visibilidade em junho de 2013, cobrindo e participando das manifestações de rua ocorridas no Brasil neste período. Suas imagens, veiculadas ao vivo e ininterruptamente pela internet, obtiveram grande audiência, pautaram a grande imprensa e tiveram grande influência na mudança de discurso da mídia hegemônica sobre o fato. A mídia alternativa se alimentou contrapondo-se ao discurso hegemônico e a grande mídia foi pautada por imagens e coberturas da mídia alternativa, fato que fugiu do habitual. A sociedade desconfiou do discurso hegemônico, mas também dos motivos e financiamento dos “ninjas”. Em meio a essas questões, nossa intenção é refletir sobre o accountability noticioso.Surgido en 2011, el grupo "Mídia Ninja" ganó más visibilidad en junio deste año, cuando cubre y participa de las manifestaciones callejeras en Brasil. Estas imágenes fueran emitidas en directo y sin interrupciones por la Internet, han tenido amplia audiencia, han guiado a la gran prensa y fueron responsables por algunos de los cambios del discurso hegemónico de los medios sobre el hecho. Los medios de comunicación alternativa se alimentan en oposición al discurso hegemónico de los médios dominantes mientras estos son pautados por imágenes y coberturas de los medios alternativos. La sociedad sospecha del discurso hegemónico, sino también de las motivaciones y financiación del grupo Ninja. En medio de estas cuestiones, reflejamos con quien se queda la responsabilidad final

In Situ β-Glucan Fortification of Cereal-Based Matrices by Pediococcus parvulus 2.6: Technological Aspects and Prebiotic Potential

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

A specific immunological method to detect and quantify bacterial 2-substituted (1,3)- β-D-glucan

30 p.-1 tab.-5 fig.-2 fig. supl.Exopolysaccharides synthesized by lactic acid bacteria have prebiotic properties and contribute to the rheology and texture of fermented foods. Here, we have standardized an immunological method for the specific detection of 2-substituted (1,3)β-d-glucans. The method allows direct detection and quantification of this exopolysaccharide in culture supernatants containing other mono- and poly-saccharides. Moreover, it allows specific detection of the biomolecules synthesized in vitro in enzymatic reactions. Thus, this method allows the fast identification of producing bacteria, as well as biochemical characterization of the glycosyltransferases responsible for their synthesis.This work was supported by the Spanish Ministry of Economy and Competiveness grants AGL2009-12998 and AGL2012-40084.Peer reviewe

Enhancement of 2-methylbutanal formation in cheese by using a fluorescently tagged Lacticin 3147 producing Lactococcus lactis strain

30 p.-6 fig.The amino acid conversion to volatile compounds by lactic acid bacteria is important for aroma formation in cheese. In this work, we analyzed the effect of the lytic bacteriocin Lacticin 3147 on transamination of isoleucine and further formation of the volatile compound 2-methylbutanal in cheese. The Lacticin 3147 producing strain Lactococcus lactis IFPL3593 was fluorescently tagged (IFPL3593-GFP) by conjugative transfer of the plasmid pMV158GFP from Streptococcus pneumoniae, and used as starter in cheese manufacture. Starter adjuncts were the bacteriocin-sensitive strains L. lactis T1 and L. lactis IFPL730, showing branched chain amino acid aminotransferase and α-keto acid decarboxylase activity, respectively. Adjunct strains were selected to complete the isoleucine conversion pathway and, hence, increase formation of 2-methylbutanal conferring aroma to the cheese. The non-bacteriocin-producing strain L. lactis IFPL359-GFP was included as starter in the control batch. Fluorescent tagging of the starter strains allowed their tracing in cheese during ripening by fluorescence microscopy and confocal scanning laser microscopy. The bacteriocin produced by L. lactis IFPL3593-GFP enhanced lysis of the adjuncts with a concomitant increase in isoleucine transamination and about a two-fold increase of the derived volatile compound 2-methylbutanal. This led to an enhancement of the cheese aroma detected by a sensory panel. The improvement of cheese flavour and aroma may be of significant importance for the dairy industry. © 2003 Elsevier B.V. All rights reserved.The research was supported by the NRI Competitive Grants Program of the United States Department of Agriculture (Grant no. 2002-35204-11662) and Schering-Plough Animal Health CorpPeer Reviewe

A methodology for the selection and characterization of riboflavin-overproducing Weissella cibaria strains after treatment with roseoflavin

21 p.-9 fig.-3 tab.Fermentative processes by lactic acid bacteria can produce metabolites of interest to the health and food industries. Two examples are the production of B-group vitamins, and of prebiotic and immunomodulatory dextran-type exopolysaccharides. In this study, three riboflavin- and dextran-producing Weissella cibaria strains (BAL3C-5, BAL3C-7 and BAL3C-22) were used to develop a new method for selection and isolation of spontaneous riboflavin-overproducing W. cibaria mutants. This method was based on the selection of strains resistant to roseoflavin. The DNA sequencing of the FMN riboswitch of bacterial cell populations treated with various roseoflavin concentrations, revealed the existence of at least 10 spontaneous and random point mutations at this location. Folding and analysis of the mutated FMN riboswitches with the RNA fold program predicted that these mutations could result in a deregulation of the rib operon expression. When the roseoflavin-treated cultures were plated on medium supporting dextran synthesis, the most promising mutants were identified by the yellow color of their mucous colonies, exhibiting a ropy phenotype. After their isolation and recovery in liquid medium, the evaluation of their riboflavin production revealed that the mutant strains synthesized a wide range of riboflavin levels (from 0.80 to 6.50 mg/L) above the wild-type level (0.15 mg/L). Thus, this was a reliable method to select spontaneous riboflavin-overproducing and dextran-producing strains of W. cibaria. This species has not yet been used as a starter or adjunct culture, but this study reinforces the potential that it has for the food and health industry for the production of functional foods or as a probiotic. Furthermore, analysis of the influence of FMN present in the growth medium, on rib mRNA and riboflavin levels, revealed which mutant strains produce riboflavin without flavin regulation. Moreover, the BAL3C-5 C120T mutant was identified as the highest riboflavin-overproducer. Determination of its chromosomal DNA sequence and that of BAL3C-5, revealed a total identity between the 2 strains except for the C120T mutation at the FMN riboswitch. To our knowledge, this work is the first demonstration that only a single alteration in the genome of a lactic acid bacteria is required for a riboflavin-overproducing phenotype.This research was funded by the Spanish Ministry of Science, Innovation and Universities (grant RTI2018-097114-B-I00), CSIC (grant COOPA20488), the University of Basque Government (grants IT1662-22 and PIBA_2020_1_0032), and the University of Basque Country (UPV-EHU; GIU19/014). ID-O is the beneficiary of a postdoctoral grant Margarita Salas by UPV-EHU (MARSA21/25) in the framework of “the requalification of the Spanish university system” funded by the European Union-Next Generation EU.Peer reviewe