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Among vegetable functional products, soy-based foods stand out for their high content in protein and flavonoids,mainly isoflavones. The fermentation of soy beverages with selected bacterial strains is a way to obtain a product,enriched in isoflavone aglycones, alongside with other isoflavone derivates and other bioactive flavonoids. Two bacterial strains with high activity on the transformation of these compounds, Limosilactobacillus mucosae INIA P508 and Bifidobacterium pseudocatenulatum INIA P815, were tested for the fermentation of soy beverage. Both strains produced high concentration of the aglycones daidzein and genistein, in addition to a significant increase (P < 0.01) of glycitein, O-desmethylangolensin, 6′′ -hydroxy-O-desmethylangolensin, tetrahydrodaidzein and other flavonoid aglycones such as kaempferol, naringenin and luteolin. Two alternatives to conserve the developed functional beverages were explored, cold storage and thermal treatment. Refrigeration did not affect the concentration of isoflavones, even observing an increase in aglycones. Similarly, the thermal treatment and further room temperature storage did not reduce the amounts of daidzein and genistein. Therefore, both strains could be used for the development of soy beverages enriched in bioactive isoflavones and other bioactive flavonoids which would maintain their concentrations in refrigeration or at room temperature after heat treatment.

8 Pág. Departamento de Tecnología de Alimentos​​, Three strains with technological and probiotic properties (Lactococcus lactis INIA 650, Lacticaseibacillus paracasei INIA P272 and Bifidobacterium breve INIA P734) were used in different combinations as adjunct cultures for the manufacture of pasteurized ewe's milk. The three strains showed good viability during cheese manufacture and ripening. Moreover, they all were able to survive after the addition of the cheese samples to an in vitro colonic model. The nisin-producing strain L. lactis INIA 650 was able to produce the antimicrobial peptide nisin not only during cheese manufacture and ripening, but also in the colonic model. None of the strains combinations added to the cheese as adjunct cultures had a negative influence in their physicochemical or sensory characteristics when compared to control cheese. This work shows the suitability of cheese as vehicle for a multi-strain combination with potential dual effect in food and gut., This work was supported by project RTA2017-00002-00-00 from the Spanish Ministry of Science and Innovation

Centro de Investigación en Sanidad Animal (CISA), Fluorescent proteins are widely used for cell and protein tracking. Most of these proteins show a high signal and need the presence of oxygen to emit fluorescence. Among them, the fluorescent protein mCherry stands up because of its bright signal and fast maturation. Furthermore, the anaerobic cyan-green fluorescent protein Evoglow-Pp1 allows fluorescent detection under anaerobic conditions. In this work, we modified the pNZ:TuR.aFP plasmid, which harbors the gene encoding Evoglow-Pp1 and the promoter of elongation factor Tu from Limosilactobacillus reuteri CECT925, to obtain a plasmid containing the mrfp gene encoding the monomeric mCherry (pNZ:TuR.mCherry). Moreover, both genes were cloned together (pNZ:TuR.aFP.mCherry) developing a chimeric protein; and with a stop codon between them (pNZ:TuR.aFP.STOP.mCherry) resulting in the expression of both Evoglow-Pp1 and mCherry proteins separately under the influence of the same promoter. Lactococcus lactis, Lacticaseibacillus casei, Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Lacticaseibacillus rhamnosus, and L. reuteri strains were transformed with the previously mentioned plasmids, showing an excellent red (pNZ:TuR.mCherry), green (pNZ:TuR.aFP), and red combined with green (pNZ:TuR.aFP.mCherry and pNZ:TuR.aFP.STOP.mCherry) fluorescence signal. Both fluorescence emissions were stable in strains transformed with pNZ:TuR.aFP.STOP.mCherry, while differences in the red or green fluorescence emission were observed in some of the strains harboring pNZ:TuR.aFP.mCherry. Moreover, these plasmids allowed strains differentiation in a complex environment, such as fecal microbiota. Hence, we present the plasmid pNZ:TuR.aFP.STOP.mCherry as a useful tool for the labeling of lactobacilli strains, which would be functional under anoxic conditions, thanks to Evoglow-Pp1, while having the high brightness and good photostability of mCherry. KEY POINTS: • LAB transformed with pNZ:TuR.mCherry expressed the red fluorescent protein mCherry. • LAB transformed with pNZ:TuR.aFP.mCherry developed a fusion of both proteins Evoglow-Pp1 and mCherry. • LAB with pNZ:TuR.aFP.STOP.mCherry expressed both fluorescent proteins separately., This work was supported by RTA2017-00002–00-00 project from the Ministry of Economy and Competitiveness (Spain).

18 Pág. Departamento de Tecnología de Alimentos​​, Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain., This work was supported by project no. RTA2017-00002-00-00 from the Spanish Ministry of Science and Innovation, by the Junta de Andalucía (CTS 164) and Instituto de Salud Carlos III (PI19/01058) with funds from the European Union