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Microbial food alterations lead to unfit products for consumption, and their discarding, to significant economic losses for the food industry. During storage, fresh foods offer available niches for the survival and growth of undesirable microorganisms. In dairy products, data regarding spoilage and/or pathogenic bacteria is better documented than those for molds and yeasts. Dairy products are less susceptible to mold's contamination than products such as fruits and vegetables, due to their refrigerated storage; their elaboration from heat-treated milk and, for fermented ones, the dominant microbiota that acidifies the medium. However, even cheeses and yogurts may be susceptible to mold contamination. Atypical cases of yogurt samples containing spoilage microorganisms not previously reported (molds producing gas and bacteria of the genus Gluconobacter) in Argentinean fermented milks are presented here. For yogurt, in particular, the “classic” altering organisms were always being yeasts, and in other countries, molds belonging to the genus Aspergillus. Fil: Capra, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Frisón, Laura Noemí. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Chiericatti, Carolina Andrea Antonia. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

In the present work, the functional roles of an exopolysaccharide (EPS) extract form Lactobacillus fermentum Lf2 were studied by means of in vitro and in vivo assays, individually or combined with a probiotic strain, Bifidobacterium animalis subsp. lactis INL1. From the in vitro assay (macrophages derived from THP-1 cell line), the EPS in its purified form caused an increase in the levels of the proinflammatory cytokine TNFα, while both forms of EPS (purified and crude) produced an increase in the regulatory cytokine IL-10, evidencing an immunomodulatory role. To study the functional role of EPS as a food ingredient, an in vivo assay was done with mice (BALB/c) that received yogurt with EPS (600 mg L-1, YE), with bifidobacteria (5x108 CFU mL-1, YB), a combination of both ingredients (YEB), or yogurt with no additives (Y), for 25 days. The level of diverse bacterial groups and Short Chain Faty Acids (SCFA) were estimated in faeces, and s-IgA and cytokines were determined in small intestine. Among the four groups, only the group YE presented significantly increased concentrations of acetic and butyric acids, together with an increase in the total SCFA (p< 0.05), through the time of treatment. The levels of the C. coccoides cluster (SCFA producing group) rose over time (p< 0.05) for this group as well. When the combination of both ingredients was studied (YEB), a possible bifidogenic role was observed, reflected in the increasing levels of the genus Bifidobacterium along time (p< 0.05), a behaviour that was not observed when the probiotic was administered solely (group YB). But, in this case, no significant differences were observed for the concentration of SCFA. These results highlight the promising application of this EPS as a functional food ingredient: with prebiotic or synbiotic potential roles, when administered individually (due to its effects on the SCFA levels) or combined with B. animalis subsp. lactis INL1 (considering the increase of Bifidobacteria during the time of treatment), respectively. Fil: Ale, Elisa Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Maxence J. Bourin. University College Cork; Irlanda Fil: Peralta, Guillermo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Avila, Olga Beatriz. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina Fil: Contini, Liliana Ester. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Using a mouse model of diet-induced obesity in males and females C57BL/6 mice, effects of a yoghurt enriched with proteins on pro-inflammatory cytokine and lipid profiles were assessed. A clear sex-dependent behaviour of the mice was shown; females gained less weight than males independent of the diet. When a high fat diet was implemented with yoghurt, a reduction of cholesterol and triglycerides in liver and blood serum of males, and triglycerides in the liver of females was observed. For male mice fed with yoghurt, a significant reduction of the levels of pro-inflammatory cytokines was detected; in female mice, the anti-inflammatory effect due to yoghurt consumption was observed only to a minor extent. Principal component analysis confirmed that gender or diet was able to group individual animals. A higher variability of data was observed in females compared with males, probably the reason why less significant differences were observed in the former.

Breast milk can be a source of potential probiotic bacteria, but the technological capacity of isolates obtained from this source is not always guaranteed. We aimed at isolating lactobacilli from breast milk samples collected in Argentina, focusing on isolates with functional and technological potential as probiotics. Fourteen Lactobacillus and one Bifidobacterium isolates were obtained from 164 samples donated by 104 mothers. The isolates preliminarily identified by MALDI-TOF, and then the identity was confirmed by partial 16S rRNA gene sequencing. Hydrophobicity was determined (hexadecane and xylene partition). The strains were also co-cultured with murine RAW 264.7 macrophages for screening the capacity to induce the anti-inflammatory cytokine interleukin (IL)-10. Hydrophobicity ranged from 7.4 and 95.9%. The strains Lactobacillus gasseri (70a and 70c) and Lactobacillus plantarum (73a and 73b) were the strains with a higher capacity to induce IL-10 production by macrophages. The technological application was evaluated by freezing dried in 10% lactose or 10% polydextrose. The survival was assessed after accelerated (37 °C, 4 weeks) or long-term (5 and 25 °C, 12 months) storage. Except for Lactobacillus gallinarum 94d, strains lost less than 1 Log10 order cfu/g after long-term (12 months) storage at 5 °C in lactose and polydextrose as protectants. A low correlation between survival to accelerated and long-term storage tests was observed. L. gasseri (70a and 70c) and L. plantarum (73a and 73b) deserve further studies as potential probiotics due to their capacity to induce IL-10 from murine macrophages and their hydrophobicity. In special, L. plantarum 73a was able to confer enhanced protection against Salmonella infection by promoting the immunity of the small intestine.

Lactobacillus fermentum Lf2 produces high amounts of exopolysaccharides (EPS) (~1 g/L) with demonstrated functional and technological roles when applied as a food ingredient in dairy matrices, properties that made these EPS interesting in comparison with other similar molecules from lactic acid bacteria (LAB). Those characteristics encouraged us to optimise the production. The EPS extract is composed of a high molecular mass β-glucan and a medium molecular mass heteroglycan. In the present work, the optimal conditions that doubled the EPS yield using a semidefined medium (SDM, 0.63% yeast nitrogen base, 0.53% bacto casitone, 0.53% ammonium citrate, 6.25% sucrose, pH 6.5) were found by means of response surface methodology (RSM). The chemical characterisation indicated that under optimised conditions the synthesis of the heteroglycan was favoured compared with that of the β-glucan. Fil: Ale, Elisa Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Batistela, Virginia Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina Fil: Correa Olivar, Gabriela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Ferrado, Joana Belén. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina Fil: Sadiq, Sohaib. University Of Huddersfield; Reino Unido Fil: Ahmed, Hafiz I.. University Of Huddersfield; Reino Unido Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vera Candioti, Luciana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Ciencias Biológicas. Cátedra de Bromatología y Nutrición; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Laws, Andrew P.. University Of Huddersfield; Reino Unido Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

We aimed at isolating and characterising microorganisms present in human breast milk with probiotic potential. In an 8-week postpartum sampling period, two strains of bifidobacteria (Bifidobacterium longum LM7a and Bifidobacterium dentium LM8a’) and four strains of lactobacilli were isolated, all during the first 4-week postpartum. B. longum LM7a and B. dentium LM8a’, together with four strains previously isolated from breast milk (Bifidobacterium lactis INL1, INL2, INL4 and INL5), were considered for further studies. Susceptibility of the strains to tetracycline, erythromycin, clindamycin, streptomycin, vancomycin and chloramphenicol was evaluated and the isolates exhibited, in general, the same properties as previously reported for bifidobacteria. All isolates showed low hydrophobicity and B. lactis and B. longum strains had satisfactory resistance to gastric digestion and bile shock, but not to pancreatin. B. lactis INL1, B. longum LM7a and B. dentium LM8a’ were selected for some comparative technological studies. In particular, B. lactis INL1 displayed technological potential, with satisfactory growth in cheese whey-based media in biofermentor and resistance to freeze-drying, accelerated storage conditions and simulated gastric digestion. Fil: Zacarías, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Bockelmann, Wilhelm. Max Rubner-institut, Germany; Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Heller, Knut. Max Rubner-institut, Germany; Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Objective: To assess the variability of secretory immunoglobulin A (S-IgA) in the lumen and feces of mice along a working day. Results: Mice were maintained under a 12 h light-dark cycle, light period starting at 8 AM. S-IgA was determined in feces and intestinal content (after one or three washes) at three points along the day: at the beginning, in the middle and at the end of the light period (ELP). Significant reduction in the content of S-IgA in the small intestine fluid and in feces was observed at the end of the light cycle, which coincides with the end of a regular working day (8 PM) in any given animal facility. It was also observed that three washes of the small intestine were more effective than one flush to recover a significant higher amount of S-IgA, with the smallest coefficient of variation observed by the ELP. A smaller CV would imply a reduced number of animals needed to achieve the same meaningful results. The results may be useful when designing animal trials for the selection of probiotic candidates based on their capacity of activating S-IgA, since it would imply a more rational use of experimental animals. Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Oddi, Sofia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Forzani, Liliana Maria. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Tabacman, Eduardo. Somalogic Inc.; Estados Unidos Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

The aim of this study is to evaluate the influence of the technological processing on the functionality of the human breast milk probiotic strain Bifidobacterium lactisINL1. In vitroantagonistic activity of B. lactisINL1 was detected for Gram‐positive and Gram‐negative pathogens. B. lactisINL1 was administered to mice as fresh (F), frozen (Z), spray‐dried (S), or lyophilized (L) culture. Immune parameters (IgA, IL‐10, and IFN‐γ) were determined and histological analysis was performed to assess functionality and protection capacity against Salmonella. In BALB/c mice, F and S cultures induced an increase in the number of IgA‐producing cells in the small intestine and IL‐10 levels were increased for L culture in the large intestine. In Swiss mice, B. lactisINL1 increased secretory‐IgA levels in the small intestine before and after Salmonellainfection, both as F or dehydrated culture. Also, an attenuation of damage in the intestinal epithelium and less inflammatory infiltrates were observed in animals that received F and S cultures, whereas in liver only F showed some effect. The anti‐inflammatory effect was confirmed in both tissues by myeloperoxidase activity and by IFN‐γ levels in the intestinal content. B. lactisINL1 showed inhibitory activity against pathogens and confirmed its probiotic potential in animal models. Technological processing of the probiotic strain affected its functionality. This work provides evidence about the influence of technology on the functionality of probiotics, which may help probiotics and functional food manufacturers to take processing into consideration when assessing the functionality of new strains.

The aim of this study was to adjust technological parameters: acidification of the curd (pH 5.25) and time (2, 5, 10 and 20 min) and stretching temperature (58, 62.5 and 68 °C) in order to make a pasta filata cheese carrying a probiotic bacterium at levels higher than 107 CFU/g. A control and a probiotic cheese were produced. Lactobacillus rhamnosus GG was used and its resistance to simulated gastrointestinal digestion (SGD) was evaluated. Gross composition and pH, microbiological analysis, proteolysis, physicochemical and sensory characteristics, volatile compounds, organic acids and sugar profiles were also determined. The probiotic remained above 3 × 107 CFU/g during its shelf life and exhibited high resistance to SGD (matrix protection of about 60%). The addition of the probiotic increased secondary proteolysis (about 30% for SN fraction in trichloracetic and phosphotungstic acids) and the production of diacetyl, acetoin, lactic and acetic acids. Sensory characteristics (smell, astringency, acid taste and residual flavor) were also modified. The development of a probiotic Fior di Latte cheese that might contribute to disease prevention and generate improvements in sensory characteristics compared to traditional products would allow expanding the market of functional foods. Fil: Cuffia, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: George, Guillermo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Renzulli, Pablo. Mastellone Hnos. S.a.; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Meinardi, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

This study was aimed to evaluate the potential of high pressure homogenization for the microencapsulation of two probiotic lactic acid bacteria, Lactobacillus paracasei A13 and Lactobacillus salivarius subsp. salivarius CET 4063 to produce functional fermented milks. Microcapsules of the considered functional microorganisms were obtained by HPH treatments at 50 MPa in the presence of sodium alginate and vegetable oil. The microencapsulated microorganisms were then inoculated as adjuncts to produce fermented milks. As controls were used fermented milks in which the two probiotic lactobacilli were inoculated without encapsulation. The viability of the strains was monitored during almost 2 months of refrigerated storage. The survival of lactic acid bacteria after the gastric-duodenal simulated test was determined. Fermented milk texture parameters, the presence of exo-polysaccharides and the production of volatile molecules were also evaluated over storage. The microcapsules, for both the considered probiotic strains, were homogeneous and with a size

Probiotic products are becoming increasingly popular worldwide. Regulators and quality control personnel need a clear path to count viable cells within each product. We have reviewed progress on the enumeration of probiotics in foods and supplements. Today, no single culture medium or combination of culture media can accurately enumerate all probiotics available. Culture-independent techniques can speed the counting process compared with traditional agar plating, but their sophistication makes them unsuitable for routine quality control in many laboratories. The enumeration of probiotics in a given product needs to be tailor-made: the response of each probiotic and starter culture used in the food or supplement to a narrow set of culture media should be assessed first to identify the proper conditions for an accurate enumeration. A standardised procedure should be developed in the near future with the consensus of the scientific, industrial and regulator communities. Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Salminen, Seppo. University of Turku. Faculty of Medicine; Finlandia

Exopolysaccharides (EPS) production is a characteristic that has been widely described for many lactic acid bacteria (LAB) of different genera and species, but little is known about the relationship between the functional properties of the producing bacteria and EPS synthesis. Although many studies were addressed towards the application of EPS-producing LAB in the manufacture of several dairy products (fermented milk, cheese) due to their interesting technological properties (increased hardness, water holding capacity, viscosity, etc.), there are not many reports about the functional properties of the EPS extract itself, especially for the genus Lactobacillus. The aim of the present revision is to focus on the species Lactobacillus fermentum with reported functional properties, with particular emphasis on those strains capable of producing EPS, and try to establish if there is any linkage between this property and their functional/probiotic roles, considering the most recent bibliography. Fil: Ale, Elisa Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Rojas, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Samples (29) of natural whey starters used in the Santa Fe (Argentina) area for hard cheese production were examined. The microbial composition (including lactic microflora identification) and technological characteristics (acidifying and proteolytic activities) were determined. The cultures consisted mainly of thermophilic lactic acid bacteria belonging to the genus Lactobacillus . L. helveticus (66% the total strains) and L. delbrueckii subsp. lactis (33%) were the dominant species. In every sample, yeasts appeared as the only natural contaminants, at variable contents. The samples showed high acidity levels (1.2 to 1.4% lactic acid) with a mean pH value of 3.3. The acidifying and proteolytic activities were high at temperatures ranging from 37 to 50°C and negligible at 55°C.

The aim of this study was to manufacture pasta filata cheeses added with two probiotic lactobacilli: Lactobacillus rhamnosus GG and Lactobacillus acidophilus LA5, either individually or combined, and to evaluate the effect of the storage temperature (4 and 12 °C) on their chemical, microbiological, and sensorial characteristics. Three cheese types were made: (i) G: containing L. rhamnosus GG, (ii) L: containing L. acidophilus LA5, and (iii) GL: containing both probiotic strains. Gross composition, pH, microbiological, and sensory characteristics were determined. No differences in gross composition were found among them. pH values remained above 5.2 in cheeses stored at 4 °C. However, a postacidification was observed in cheeses ripened at 12 °C. L. acidophilus LA5 was not able to grow, while L. rhamnosus GG grew 1.5 log10 CFU/g in G and GL cheeses stored at 12 °C, reducing the pH from day 8 onwards. These results emphasize the importance of the storage temperature since the good characteristics of probiotic cheeses are kept if the cold-chain is respected. Thus, the selection of probiotics, together with the food matrix and the starter, should be carefully evaluated. Fil: Cuffia, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Pavón, Yanina Lorena. Universidad Nacional de Litoral; Facultad de Ingeniería Química; Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: George, Guillermo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Functional foods can be defined as foods and food components that provide a health benefitbeyond basic nutrition (IFT Expert Report, 2014). Nowadays, the demand for functional foods isincreasing all over the world and constitutes one of the most rapidly growing sectors of the foodindustry (Kearney, 2010). The current legislation indicates that food labels must have clear andaccurate information so that consumers are informed when choosing a food (Salminen and vanLoveren, 2012). Despite this, only few countries have their own directives and regulations regardingfunctional foods. Even though specific laws should exist about probiotic microorganisms and theirassociated health claims, it is a challenge for scientists and the industrial sector to demonstrate therelationship of probiotics with a health effect.Regulations governing the incorporation of novel probiotics may vary a lot with the geographicalregion considered. The greatest advances in this subject were done in European countries, Japan,Canada, and the United States. Latin America is one of the regions with more diverse andasymmetrical legislation among constituting countries. Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Tomei, Daniela. Meta Regulatoria; Brasil Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Aim: To characterize four novel autochthonous bifidobacteria isolated from monkey faeces and a Bifidobacterium lactis strain isolated from chicken faeces by evaluating their technological and biological/functional potential to be used as probiotics. Different stressors, including food process parameters and storage, can affect their viability and functionality. Methods and Results: The resistance to frozen storage, tolerance to lyophilization and viability during storage, thermal, acidic and simulated gastric resistance, surface hydrophobicity and antimicrobial activity against pathogens were studied. Bifidobacterium lactis Bb12 and INL1 were used as reference strains. The results obtained demonstrated that the new isolates presented strain-dependent behaviour. Good results were obtained for thermal resistance, frozen storage at −80°C and lyophilized powders maintained at 5°C. Cell viability during refrigerated storage was higher when the strains were resuspended in milk at pH 5·0 than at 4·5. The surface hydrophobicity ranged between 7 and 98% depending on the strain. The simulated gastric resistance was improved for the strains incorporated in cheese. Regarding antimicrobial activity, bifidobacteria isolated from monkey presented higher inhibitory capacity than the reference strains. Conclusion: This research provides a deeper insight into new strains of bifidobacteria isolated from primates and chicken that have not been previously characterized for their potential use in dairy products and confirm the most robust stress tolerance of B. lactis. Significance and Impact of the Study: The possibility of expanding the available bifidobacteria with the potential to be added to a probiotic food necessarily implies characterizing them from different points of view, especially when considering unknown species. For monkey isolates (which showed higher antimicrobial activity against pathogens), more in-depth knowledge is needed before applying strategies to improve their performance. On the contrary, the chicken isolate B. lactis P32/1 showed similar behaviour to the references B. lactis strains; therefore, it could be considered as a potential probiotic candidate. Fil: Sarquis, Maria de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Siroli, Lorenzo. Dipartimento Di Scienze E Tecnologie Agro-alimentari; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Modesto, Mónica. Universidad de Bologna; Italia Fil: Patrignani, Francesca. Dipartimento Di Scienze E Tecnologie Agro-alimentari; Italia Fil: Lanciotti, Rosalba. Dipartimento Di Scienze E Tecnologie Agro-alimentari; Italia Fil: Mattarelli, Paola. Universidad de Bologna; Italia Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

AIM:To determine the protective capacity against Salmonella infection in mice of the cell-free fraction (postbiotic) of fermented milk, produced at laboratory and industrial level.METHODS AND RESULTS:The proteolytic activity (PA) of five commercial cultures and eleven autochthonous Lactobacillus strains was evaluated. The DSM-100H culture displayed the highest PA and it was selected for further studies. The capacity of the postbiotics produced by pH-controlled fermentation to stimulate the production of secretory-IgA in faeces and to protect mice against Salmonella infection was evaluated. A significant increase of S-IgA in faeces of mice fed 14 days the postbiotic obtained at the laboratory (F36) was detected compared to control animals. A significantly higher survival was observed in mice fed the F36 and the FiSD (industrial product) compared to controls.CONCLUSION:The postbiotics obtained showed immunomodulatory and protective capacity against Salmonella infection in mice.SIGNIFICANCE AND IMPACT OF THE STUDY:The pH-controlled milk fermentation by the proteolytic DSM-100H culture could be a suitable strategy to obtain a food ingredient to be added to a given food matrix, not adequate to host viable cells of probiotics, to confer it enhanced functionality and thus expand the functional food market. This article is protected by copyright. All rights reserved. Fil: Dunnand, E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Bergamini, Carina Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Peralta, Guillermo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Forzani, Liliana Maria. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Functional properties of two Lactobacillus plantarum strains (Lp 813 and Lp 998) were evaluated ( in vitro) before and after heat adaptation and shock. The stress conditions were selected considering a previous work: 55 °C - 15 min (heat shock) and 45 °C - 30 min (thermal adaptation), both performed in MRS broth. The functional properties evaluated were: a-survival to simulated gastrointestinal tract (GIT: saliva + bovine pepsina solution brought to pH 2.3 in 90 min, bile solution 1% w/v pH 8-10 min and bile + pancreatin solution pH 8-30 min), b-co-aggregation with Saccharomyces cerevisiae to simulate intestinal epithelia adhesion, c- auto- and co-aggregation with enteric pathogens ( Escherichia coli and Salmonella enteritidis) and d-use of prebiotic compounds (inulin, soluble corn fiber, lactulose and raffinose) evaluated for kinetics of growth. Heat treatments (generally) affected the studied functional properties as follows: a-diminished the resistance to acidic step and improved survival undergoing bile-pancreatin step in GIT simulation, b-mean values of auto-aggregation and co-aggregation with yeast or pathogens were not significantly modified, despite an increase in variability and c-prebiotic use diminished in the case of strains subjected tothermal treatments except for raffinose, which showed to have been better employed in this last case. These results could be very useful when it comes to the selection of microorganisms to be used and conserved in processes and methodologies that involve high temperatures as a stress factor (spray drying or cheese elaboration). Fil: Ferrando, Verónica Andrea. Universidad Nacional del Litoral; Argentina Fil: Quiberoni, Andrea del Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Suárez, Viviana Beatriz. Universidad Nacional del Litoral; Argentina

Bifidobacterium animalis subsp. lactis IPLA 20020 and Lactobacillus gasseri IPLA 20212, two strains isolated from human samples, were evaluated for safety and influence over the intestinal microbiota and cytokine production by the intestinal tissue of adult BALB/c mice. Mice were divided into four groups receiving during 8 days PBS or a suspension of each strain, prepared fresh or lyophilized (bifidobacteria), at an amount of 4x108 viable cells/day. This dose could be comparable to the probiotic intake of a human adult who consumed about 100-200 mL of functional fermented milk per day, considering the usual level of probiotics in commercial products. No microbial translocation to liver or alterations in food intake, weight, and behavior were observed in treated mice. Intestinal content of secretory immunoglobulin A (s-IgA) was not affected, discarding any adverse effect on the mucosa-associated immunity. The profile of intestinal proinflammatory/regulatory cytokines after intervention evidenced that the microbial strain administered and its cellular state (fresh or lyophilized) as well as the host tissue analyzed (small or large intestine) influenced the immune response and suggests a moderate shift towards a T helper 1 profile (Th1) in the large intestine after the administration of both strains. Changes on relative levels of some intestinal microbial groups were evidenced after intervention. It is noteworthy that butyrate was positively associated with a balanced pro-Th1 immune response. Therefore, B. animalis subsp. lactis IPLA20020 and L. gasseri IPLA 20212 could be considered potential probiotic candidates to be included in functional foods for balancing the intestinal immune response., The present work was financed by the following projects: AGL2013-43770-R and PCIN-2015-233 (Project EarlyMicroHealth from the EU Joint Program Initiative HDHL), funded by the Spanish Plan Estatal de I+D+I (Ministry of Economy and Competitiveness; MINECO), Project PICT-2016-0256 supported by the Argentinian Scientific and Technological Research Funds (FonCyT), and grant GRUPIN14-043 funded by Plan Regional de Investigación del Principado de Asturias, Spain. Alicja M. Nogacka benefits from a predoctoral contract granted by MINECO. Nuria Salazar was the recipient of a Juan de la Cierva postdoctoral contract granted by MINECO and she is currently the recipient of a postdoctoral contract awarded by the Fundación para la Investigación Biosanitaria de Asturias (FINBA). The critical reading of the manuscript and useful comments of Dr. Sonia González (Department of Functional Biology, University of Oviedo, Spain) are acknowledged.

This study aimed to evaluate the resistance, viability, and functionality of two strains of probiotics immobilizedin solid lipid microparticles covered by a complex of gelatin and gum Arabic. Microcapsules were evaluatedregarding their size, morphology, and resistance under stress conditions. Encapsulated microorganisms wereevaluated concerning during storage for 120 days. Additionally, the effect of encapsulation on the functionalityof the microorganisms was investigated using an in vivo assay. Microcapsules had sizes around 80 μm and extreme pH and temperature of 50 °C destabilized them. Encapsulation improved the stability of these microorganisms in the presence of salt and in gastrointestinal conditions. Encapsulated microorganisms maintainedtheir viability during storage and the dosage of S-IgA and cytokines (IL-2, IL-6, IL-10, and TNF-α) in miceindicated that encapsulated microorganisms maintained their functionality. Therefore, the microencapsulationtechnique may be promising for the improvement of the viability of probiotics under adverse conditions withoutcompromising their immunomodulating capacity. Fil: Matos-Jr, Fernando Eustáquio. Faculdade de Zootecnia E Engenharia de Alimentos; Brasil Fil: Silva, Marluci Palazzolli. Faculdade de Zootecnia E Engenharia de Alimentos; Brasil Fil: Kasemodel, Marcia Gabriela Consiglio. Faculdade de Zootecnia E Engenharia de Alimentos; Brasil Fil: Santos, Tizá Teles. Universidade Estadual de Santa Cruz; Brasil Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Favaro-Trindade, Carmen Sílvia. Faculdade de Zootecnia E Engenharia de Alimentos; Brasil

Lactobacillus fermentum Lf2, an Argentine cheese isolate, can produce high concentrations of exopolysaccharides (EPS). These EPS were shown to improve the texture and rheology of yogurt, as well as to play a protective role in mice exposed to Salmonella enterica serovar Typhimurium., Lactobacillus fermentum Lf2, an Argentine cheese isolate, can produce high concentrations of exopolysaccharides (EPS). These EPS were shown to improve the texture and rheology of yogurt, as well as to play a protective role in mice exposed to Salmonella enterica serovar Typhimurium. Three gene clusters potentially involved in EPS production were identified in different locations of the L. fermentum Lf2 genome.

The aim of this study was to isolate, identify and characterize lactic acid bacteria (LAB) from spontaneously fermented maize silage, and evaluate their performance as spray-dried (SD) cultures to enhance the fermentation and the aerobic stability of maize micro-silos. Eleven strains of LAB were characterized for growth kinetics, the capability to grow in vegetable-based medium (VBM), production of organic acids and the ability to tolerate heat–stress. Three strains (Lactobacillus plantarum Ls71, Pediococcus acidilactici Ls72, and Lactobacillus buchneri Ls141) were selected and further characterized for the ability to grow as single strain or in co-culture in MRS and VMB medium, to survive at freeze and spray-drying process, for their performance as SD bacteria in micro-silos and for the aerobic stability in bucket silos. L. buchneri Ls141 showed the highest growth capability in VBM and produced the highest amount of acetic acid, while L. plantarum Ls71 produced the highest amounts of lactic acid. P. acidilactici Ls72 was the most heat-resistant strain, with a reduction of 0.2 log10 CFU/mL (15 min at 55°C). The three strains satisfactorily tolerated both spray and freeze-drying. After 4 days of fermentation, all the samples reached a pH value of about 3.7–3.8. A significantly lower cell load of filamentous fungi and yeasts (< 3 log10 CFU/g) and a higher concentration of total LAB (> 8.7 log10 CFU/g) was observed after 30 days of fermentation. A greater amount of acetic acid, crude protein, ash and ammonia nitrogen/total nitrogen was detected in inoculated silages. A significant reduction of filamentous fungi and yeasts was also observed in inoculated bucket silos after 50 d of fermentation. The aerobic stability was significantly improved in inoculated silage since the temperature remained stable after 16 days (384 h). On the contrary, an increase of 5°C was observed in control samples after 1 day. The selected strains have the potential to be produced as SD silage inoculant as they were able to accelerate the fermentation process, to control filamentous fungi and yeasts, to improve some nutritional and chemical parameters of silage and to improve aerobic stability. Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Borgo, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Puntillo, Melisa Anahí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Bergamini, Carina Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Páez, Roxana. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Mazzoni, Rodolfo. Fragaria Srl; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Caseinomacropeptide (CMP) is the 64 C-terminal amino acid residue of κ-casein, formed by chymosin cleavage during cheese manufacture. This study examined the effects of oral administration of a CMP-enriched extract (CMPEE), obtained from a local dairy plant, on the Ca content of mouse femurs. Animals received low (0.1%, w/v), normal (0.5%, w/v) or high (1.2%, w/v) Ca diet for 3 or 8 weeks and CMPEE diluted (1:10) in their drinking water. No significant differences in Ca content were observed in faeces, kidney, urine or blood serum compared with control animals. The oral administration of CMP to mice significantly enhanced the Ca content in femur under a low-Ca diet model, especially during the period of full body development (3 weeks), in which case a significant 12% Ca increase was observed. These findings pave the way for further studies aimed at supplementing infant food with industrially-obtained CMP-enriched extract for enhanced bone health.

Aims: To evaluate the effects of spray drying of Lactobacillus rhamnosus 64 on its capacity to modulate the gut immune response and on the attenuation of TNBS-induced colitis in mice. Methods and Results: Lactobacillus rhamnosus 64 was spray dried in cheese whey-starch solution and administered to mice for 3, 6 or 10 consecutive days. Peritoneal macrophage phagocytic activity, secretory IgA levels in the small intestinal fluid and TNFα, IFNγ, IL-10, IL-6 and IL-2 levels in homogenates of the small and large intestine were determined. The effects of spray drying were also evaluated in an acute model of Trinitrobenzenesulfonic acid (TNBS)-induced colitis. A shift in the regulation of immune parameters, particularly the cytokine profile, was observed for mice treated with the spray-dried culture, compared to the profile observed in animals that received the strain as fresh culture (FC). The spray-dried culture of L. rhamnosus 64 showed anti-inflammatory properties in murine model of TNBS-induced colitis. Conclusions: The spray-drying process of L. rhamnosus 64 in whey-starch modified its immunomodulating capacity in healthy animals and conferred enhanced protection in an in vivo model of inflammation. Significance and Impact of the Study: Probiotic capacity can be affected by spray drying in relation to the properties observed for the strain as an overnight FC. This fact should be taken into account when producing the culture for its application in the industry. Fil: Lavari, Luisina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Páez, R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Technological, biological and functional attributes of two groups of spontaneous bacteriophage-resistant mutants were investigated to verify features similar to those of their respective phage-sensitive parent probiotic strains (Lactobacillus casei/paracasei). A derivative from each group was challenged with phages in simulated probiotic product fermentation. Technological performance, compared with the original strains, was demonstrated. Minimal variations were detected in acidifying and enzymatic profiles. No β-glucuronidase activity was observed, but very high α-glucosidase and β-galactosidase activities were recorded. Low proteolytic activities and inability to ferment prebiotics were observed. Within one group, significant differences throughout simulated gastrointestinal-transit were observed. Neither of the strains deconjugated bile salts, but all showed inhibitory activity against four pathogens. Both mutants increased IgA-producing cell numbers in vivo in a manner similar to that of the parent strains. Two derivatives demonstrated improved phage-resistance phenotype compared with the parental strains, resulting in alternatives for industrial rotation schemes. Fil: Capra, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Tibaldo, Maximiliano M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Quiberoni, Andrea del Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Lactologia Industrial; Argentina

The aim of this study was to evaluate the influence of microbiological and technological factors on the viability and functionality of probiotic Lactobacillus strains. In particular, the influence of harvesting time, food matrix, refrigerated storage, time of inoculation and refrigerated storage in fermented milk on the resistance to simulated gastric digestion (RSGD) was evaluated. Moreover, strain resistance to simulated gastric digestion was compared to human gastric fluid. Results showed that the variables studied affected, in a different way and in a strain-dependent manner, the RSGD. No direct relation was observed between cell viability and RSGD.

Nowadays, there is a great interest of food industries on the development of innovative dairy products containing probiotic bacteria. Beyond yoghurt, cheeses could be a suitable matrix for the incorporation of probiotics. This work aimed to study the impact of the addition of two probiotic lactobacilli (L. rhamnosus GG and L. acidophilus LA5), either individually or combined, on the physicochemical and sensory characteristics of pasta filata soft cheeses and to evaluate the immunomodulating capacity of the product using an in vivo model. Four cheese types were produced: C-C (control cheese); L-C (added with L. acidophilus LA5); GG-C (added with L.rhamnosus GG) and GGL-C (added with both probiotics). No differences in gross composition were found. An increase in secondary proteolysis was observed in GGL-C cheeses which correlated with a greater bitter and aftertaste. On the contrary, the L-C cheese received the highest overall quality score. The translocation assay was negative. Moreover, the three experimental cheeses were able to modulate the immune system of mice by reducing the secretion of pro-inflammatory cytokines in the intestine, downregulating the levels of interleukin(IL)-10 and increasing the secretion of Secretory Immunoglobulin A (S-IgA). No synergistic effect was detected when both probiotics were added. Fil: Cuffia, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: George, Guillermo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Godoy, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Some strains of the genus Bifidobacterium are considered probiotics and can be added as adjunct cultures to functional dairy products. Lactobacillus delbrueckii subsp. lactis is used as a starter in food fermentations. The influence of co-culturing strains Bifidobacterium longum NCIMB 8809 and L. delbrueckii subsp. lactis 193 on the physiology and heat tolerance of these microorganisms was studied. 2DE coupled to MS protein analysis allowed the identification of several proteins from each bacterium whose expression changed when cells were grown in compartmentalized co-cultures compared to mono-cultures. Remarkably, production of stress response chaperones was enhanced in both strains and was related with increased survival to heat shock, a technologically suitable property in the manufacture of some dairy products. This study provides the first insight in understanding communication between B. longum and L. delbrueckii subsp. lactis. © 2013 Elsevier Ltd. Fil: Sanchez, Borja. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España; Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Ruiz, Lorena. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España; Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; Argentina Fil: Margolles, Abelardo. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España; Fil: Ruas Madiedo, Patricia. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España; Fil: de Los Reyes-Gavilan, Clara G.. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España

The aim of this work was to assess if a sub-lethal high pressure homogenization (HPH) treatment could modulate in vitro functional and biological properties of probiotic bacteria. Lactobacillus paracasei A13, Lactobacillus acidophilus 08 and Dru, Lactobacillus delbrueckii subsp. lactis 200 and bile-resistant derivatives L. acidophilus Druþ and L. delbrueckii subsp. lactis 200þ were suspended in phosphate buffered saline solution and treated at 50 MPa. Data obtained showed that HPH can modulate hydrophobicity and auto-aggregation without modification of viability and decarboxylase activity. Resistance to simulated gastric conditions resulted strain-dependent. High resistance was observed for treated L. paracasei A13, L. acidophilus Dru and 08 and L. delbrueckii subsp. lactis 200. The HPH-treatment reduced the resistance to simulated stomach duodenum-passage of L. acidophilus Dru while increased it for L. paracasei A13. Strain viability and resistance to simulated gastric conditions were evaluated treating at 50 MPa cells suspended in acidified buttermilk (pH 4.6) and stored at 4 C for 30 days. The highest cell viability loss, after 30 d of refrigerated storage, was observed for L. acidophilus Dru, independently of the application of HPH. However, after 30 days of storage, the resistance of L. paracasei A13 to simulated gastric digestion significantly increased in HPH treated cells.

Buttermilk is a suitable substrate for fermentation with proteolytic strains of Lactobacillus in order to release peptide fractions able to enhance the gut mucosal immune system. We aimed to determine the influence of the degree of proteolysis of buttermilk proteins on their functionality. Animals received for seven consecutive days the cell-free fraction of 10 or 20% (w/v) buttermilk fermented with Lactobacillus delbrueckii subsp. lactis 210 at pH 6. The pH was controlled either with NaOH or Ca(OH)2. No significant differences in the number of IgA-producing cells in the small intestine of mice were found. The functional capacity of the product under study was not affected by the technological variables considered.

Specific strains should only be regarded as probiotics if they fulfill certain safety, technological and functional criteria. The aim of this work was to study, from a comprehensive point of view (in vitro and in vivo tests), three Lactobacillus strains (L. paracasei JP1, L. rhamnosus 64 and L. gasseri 37) isolated from feces of local newborns, determining some parameters of technological, biological and functional relevance. All strains were able to adequately grow in different economic culture media (cheese whey, buttermilk and milk), which were also suitable as cryoprotectants. As selective media, LP-MRS was more effective than B-MRS for the enumeration of all strains. The strains were resistant to different technological (frozen storage, high salt content) and biological (simulated gastrointestinal digestion after refrigerated storage in acidified milk, bile exposure) challenges. L. rhamnosus 64 and L. gasseri 37, in particular, were sensible to chloramphenicol, erythromycin, streptomycin, tetracycline and vancomycin, increased the phagocytic activity of peritoneal macrophage and induced the proliferation of IgA producing cells in small intestine when administered to mice. Even when clinical trails are still needed, both strains fulfilled the main criteria proposed by FAO/WHO to consider them as potential probiotics for the formulation of new foods. Fil: Gregoret, Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Perezlindo, M. J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Probiotic microorganisms are mainly bacteria from the genera Lactobacillus and Bifidobacterium that exert a health benefit on the host when consumed on a regular basis as dietary supplements or in foods. The fermented dairy industry was the first in successfully marketing specific strains of probiotic bacteria in products such as yogurts and fresh cheeses. Factors such as growing vegetarianism including veganism among consumers, lactose intolerance, allergy to milk proteins, cholesterol content of dairy products, and religious or dietary habits have limited the growth of the market of probiotics in dairy products and impaired their consumption by people interested in a healthier diet. Plant material such as cereal, legumes, fruits, and vegetables, and their combinations, offer a plethora of possibilities for the development of probiotic products, fermented or not. Much of the knowledge learned in the last 30 years about probiotics in dairy products is paving the way for the development of new nondairy foods and drinks.

Lactobacillus fermentum Lf2 is a strain which is able to produce high levels (approximately 1 g/l) of crude exopolysaccharide (EPS) when it is grown in optimised conditions. The aim of this work was to characterize the functional aspects of this EPS extract, focusing on its application as a dairy food additive. Our findings are consistent with an EPS extract that acts as moderate immunomodulator, modifying s-IgA and IL-6 levels in the small intestine when added to yogurt and milk, respectively. Furthermore, this EPS extract, in a dose feasible to use as a food additive, provides protection against Salmonella infection in a murine model, thus representing a mode of action to elicit positive health benefits. Besides, it contributes to the rheological characteristics of yogurt, and could function as a food additive with both technological and functional roles, making possible the production of a new functional yogurt with improved texture. Fil: Ale, Elisa Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Perezlindo, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Tabacman, Eduardo. Somalogic, Inc.; Estados Unidos Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina

Lactobacillus fermentum Lf2, an autochthonous strain isolated as a non starter culture in Cremoso cheese, produces high EPS levels (~ 1 g/L) in optimized conditions (SDM broth, pH 6.0, 30 °C, 72 h). Technological (texture profile and rheological analysis) and sensory properties of non-fat yogurts with 300 and 600 mg EPS/L were studied at 3 and 25 days after manufacture. Yogurts with different EPS concentrations showed higher hardness values than the control group at both periods of time, being the only significant difference that remained stable during time. The consistency index was also higher for the treated samples at both times evaluated, being significantly different for samples with 300 mg/L of EPS extract, while the flow behavior index was lower for EPS-added yogurts. The thixotropic index was lower (P

The effect of high pressure homogenization (HPH) with respect to a traditional heat treatment on the inactivation, growth at 8°C after treatments, and volatile profile of adventitious Leuconostoc strains isolated from Cremoso Argentino spoiled cheeses and ingredients used for their manufacture was evaluated. Most Leuconostoc strains revealed elevated resistance to HPH (eight passes, 100 MPa), especially when resuspended in skim milk. Heat treatment was more efficient than HPH in inactivating Leuconostoc cells at the three initial levels tested. The levels of alcohols and sulfur compounds increased during incubation at 8°C in HPH-treated samples, while the highest amounts of aldehydes and ketones characterized were in heated samples. Leuconostoc cells resuspended in skim milk and subjected to one single-pass HPH treatment using an industrial-scale machine showed remarkable reductions in viable cell counts only when 300 and 400 MPa were applied. However, the cell counts of treated samples rose rapidly after only 5 days of storage at 8°C. The Leuconostoc strains tested in this work were highly resistant to the inactivation treatments applied. Neither HPH nor heat treatment assured their total destruction, even though they were more sensitive to the thermal treatment. To enhance the inhibitory effect on Leuconostoc cells, HPH should be combined with a mild heat treatment, which in addition to efficient microbial inactivation, could allow maximal retention of the physicochemical properties of the product.

A novel treatment using polyphosphates to protect cheeses against superficial mould growth was assayed. The treatments were: control commercial paint with natamycin (I), commercial paint based on polyvinyl–water (II), immersion in a saturated solution of polyphosphate (III), immersion and commercial paint (IV), commercial paint of polyphosphate solutions (V) and immersion and commercial paint of a saturated solution of polyphosphates (VI). The cheeses were ripened for 6 months. Superficial mould growth was inhibited in groups IV and VI when compared to cheeses from the control group (I). Statistical sensory analysis made between cheeses from groups IV and I (control) showed no significant differences.

A total of 81 spontaneous phage-resistant mutants were isolated from two sensitive Lactobacillus plantarum strains (ATCC 8014 and PLN) using two lytic bacteriophages (ATCC 8014-B1 and ATCC 8014-B2), either separately or mixed in a phage cocktail. Phenotypic characteristics related to their phage resistance abilities, as well as their technological properties, were determined. Random amplification of polymorphic DNA (RAPD-PCR) was used to determine genetic diversity among the selected isolates and their respective parent strains. Most of the mutants isolated were completely or partially unable to adsorb phage particles. Stability, high level of resistance and adequate technological properties were exhibited by the isolates of Lb. plantarum ATCC 8014. A selected variant, MC4, was able to resist the mixture of both lytic phages during fermented milk manufacture and the subsequent refrigerated storage. This phage-resistant derivative might be used in culture rotation programs when commercial strains become sensitive to phages present in industrial environments.

In this paper, the photocatalytic inactivation efficiency of phages infecting lactic acid bacteria (LAB) was evaluated. Ten bacteriophages (ATCC 15807-B1, 832-B1, 0241, 204, 342, MLC-A, J-1, OBJ, CHD and QF9) dispersed on TiO 2 -coated plates were exposed to UV-A radiation during different periods of time. Two kinds of efficiencies were defined and assessed: (i) the apparent photonic yield and (ii) the quantum yield of inactivation. Considering all phages studied in this work, dissimilar values of inactivation efficiencies were found; the results differ in more than one order of magnitude. The highest inactivation efficiency was found for the bacteriophage J-1, whereas the lowest one was obtained for the phage 342. The data presented in this work can provide useful information to design innovative and effective treatments to be applied in laboratories and industrial plants which handle LAB strains.

Ninety-eight Lactobacillus plantarum strains isolated from Italian and Argentinean cheeses were evaluatedfor probiotic potential. After a preliminary subtractive screening based on the presence of msa andbsh genes, 27 strains were characterized. In general, the selected strains showed high resistance tolysozyme, good adaptation to simulated gastric juice, and a moderate to low bile tolerance. The capacityto agglutinate yeast cells in a mannose-specific manner, as well as the cell surface hydrophobicity wasfound to be variable among strains. Very high b-galactosidase activity was shown by a considerablenumber of the tested strains, whereas variable prebiotic utilization ability was observed. Only tetracyclineresistance was observed in two highly resistant strains which harbored the tetM gene, whereasnone of the strains showed b-glucuronidase activity or was capable of inhibiting pathogens. Three strains(Lp790, Lp813, and Lp998) were tested by in vivo trials. A considerable heterogeneity was found amonga number of L. plantarum strains screened in this study, leading to the design of multiple cultures tocooperatively link strains showing the widest range of useful traits. Among the selected strains, Lp790,Lp813, and Lp998 showed the best probiotic potential and would be promising candidates for inclusionas starter cultures for the manufacture of probiotic fermented foods. Fil: Zago, M.. Consiglio Per la Ricerca In Agricoltura E L' Analisi del L' Economía Agraria. Centro de Ricerca Per Le Produzioni Foraggere E Lattier-casearie; Italia Fil: Fornassari, M.. Consiglio Per la Ricerca In Agricoltura E L' Analisi del L' Economía Agraria. Centro de Ricerca Per Le Produzioni Foraggere E Lattier-casearie; Italia Fil: Carminati, D.. Consiglio Per la Ricerca In Agricoltura E L' Analisi del L' Economía Agraria. Centro de Ricerca Per Le Produzioni Foraggere E Lattier-casearie; Italia Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Suárez, Viviana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina Fil: Giraffa, Giorgio. Consiglio Per la Ricerca In Agricoltura E L' Analisi del L' Economía Agraria. Centro de Ricerca Per Le Produzioni Foraggere E Lattier-casearie; Italia

Six isolates of Bifidobacterium animalis subsp. lactis were obtained out of 16 samples of breast milk and were present in levels ranging from 1.4 to 2.8 log cfu mL−1. Isolates were stable in frozen storage (−20 °C and −70 °C, 6 months) and to refrigerated storage (5 °C, 4 weeks) in lactic acid-acidified milk (pH 4.5). Isolates were also able to grow in skim milk with yeast extract and they were stable to spray-drying in 20% (w/v) skim milk. Spray-dried cultures maintained a high number of viable cells when stored at 5 °C for 6 months and were stable to rehydration in water up to 50 °C. The oral administration of B. animalis subsp. lactis INL1 to mice increased the number of IgA+ cells in the small and large intestine. B. animalis subsp. lactis INL1 showed technological and probiotic potential for its incorporation to dairy products, whether fermented or not.

Aims: To isolate and characterize bacterial strains derived from Lactobacillus casei and Lactobacillus paracasei strains and resistant to phage MLC-A. Methods and Results: Two of nine assayed strains rendered resistant mutants with recovery efficiencies of 83% (Lact. paracasei ATCC 27092) and 100% (Lact. casei ATCC 27139). DNA similarity coefficients (RAPD–PCR) confirmed that no significant genetic changes occurred while obtaining resistant mutants. Neither parent nor mutant strains spontaneously released phages. Phage-resistant mutants were tested against phages PL-1, J-1, A2 and MLC-A8. Lactobacillus casei ATCC 27092 mutants showed, overall, lower phage resistance than Lact. paracasei ATCC 27092 ones, but still higher than that of the parent strain. Lactobacillus paracasei ATCC 27092 mutants moderately adsorbed phage MLC-A only in calcium presence, although their parent strain successfully did it with or without calcium. Adsorption rates for Lact. casei ATCC 27139 and its mutants were highly influenced by calcium. Again, phage adsorption was higher on the original strain. Conclusions: Several isolates derived from two Lact. casei and Lact. paracasei strains showed resistance to phage MLC-A but also to other Lact. casei and Lact. paracasei phages. Significance and Impact of the Study: This study highlights isolation of spontaneous bacteriophage-resistant mutants from Lact. casei and Lact. paracasei as a good choice for use in industrial rotation schemes.

Some species of Leuconostoc are very important for fermented dairy products, as they contribute to the organoleptic characteristics of butter and cream, and also contribute to the formation of openings in some soft, semi-hard (Edam and Gouda cheeses), many artisanal or in blue-veined cheeses, such as Roquefort. In this study, 14 Leuconostoc strains isolated from cheese and cheese-related products were characterized by genotypic and phenotypic methods, and their technological performance assessed for their potential use as dairy adjunct starters. Phenotypic characterization allowed these strains to be classified to genus level, and genotypic studies (RAPD-PCR and 16S rRNA gene sequencing) identified them to species/subspecies level. Five Leuconostoc strains grew well and acidified milk, and most of them grew even at 8 °C. They showed moderate resistance to heat treatments (30 min at 63 °C) and grew well in the presence of 3% and 4% NaCl, and were significantly inhibited at pH ≤ 5. All strains showed resistance against the bacteriophages tested. In general, the antibacterial properties observed were slight and due to acid production, with the exception of Leuconostoc citreum MB1, which strongly inhibited Listeria monocytogenes ATCC 15313 by the production of a bacteriocin-like compound. All Leuconostoc strains studied were susceptible to gentamicin, tetracycline, erythromycin and ampicillin. Some strains also showed interesting technological and antimicrobial properties, thus being potentially appropriate as adjunct starters in fermented dairy products. This study highlights that adventitious lactic acid bacteria can be a great source of novel strains with interesting technological features that could be used for fermented dairy foods.

Aims: The aim of this work was to study the adsorption step of two new temperate bacteriophages (Cb1/204 and Cb1/342) of Lactobacillus delbrueckii and to isolate phage-resistant derivatives with interesting technological properties. Methods and Results: The effect of divalent cations, pH, temperature and cell viability on adsorption step was analysed. The Ca2+ presence was necessary for the phage Cb1/342 but not for the phage Cb1/204. Both phages showed to be stable at pH values between 3 and 8. Their adsorption rates decreased considerably at pH 8 but remained high at acid pH values. The optimum temperatures for the adsorption step were between 30 and 40°C. For the phage Cb1/342, nonviable cells adsorbed a lower quantity of phage particles in comparison with the viable ones, a fact that could be linked to disorganization of phage receptor sites and/or to the physiological cellular state. The isolation of phage-resistant derivatives with good technological properties from the sensitive strains and their relationship with the cell heterogeneity of the strains were also made. Conclusions: Characterization of the adsorption step for the first temperate Lact. delbrueckii phages isolated in Argentina was made, and phage-resistant derivatives of their host strains were obtained. Significance and Impact of the Study: Some phage-resistant derivatives isolated exhibited good technological properties with the prospective to be used at industrial level.

This study investigated the gastric acid resistance of Lactobacillus casei in commercial fermented milks during refrigerated storage. Samples of fermented milks (natural, strawberry, fruits of the forest, vanilla and multifruits) were obtained from three different manufacturers. In vitro gastric acid resistance (GAR) was assessed in samples upon arrival to the laboratory and after 10 and 20 days of refrigerated storage at 5 °C and 12 °C. The GAR of L. casei in fermented milks may increase or decrease during storage in relation to the flavour and storage conditions. The occurrence of this phenomenon in commercial fermented milks containing probiotic bacteria may induce changes in their functionality after consumption.

Prophages account for most of the genetic diversity among strains of a given bacterial species, and represent a latent source for the generation of virulent phages. In this work, a set of 30 commercial, collection and dairy-isolated Lactobacillus casei group strains were used. A species-specific PCR assay allowed a reclassification, mainly of strains previously considered Lactobacillus casei, into either Lactobacillus paracasei or Lactobacillus rhamnosus. All the strains were induced with mitomycin C, allowing direct recovering of phage DNA in 25 cases, which corroborates the widely occurrence of lysogeny on Lactobacillus genomes, including probiotic strains of Lactobacillus casei group. Ten out of 11 commercial strains studied contained prophages, evidencing the potential risks of their use at industrial scale. Strains were also induced by treatment with different concentrations of hydrogen peroxide but, however, this agent was not able to evidence a prophage release for any of the strains tested. According to a RAPD-PCR fingerprinting with M13, 1254 and G1 primers, most of the commercial strains presented a high degree of homology and, regarding BglII- and BamHI-restriction profiles of phage DNA, six of them harboured the same prophage. Surprisingly, both Lactobacillus paracasei ATCC 27092 and Lactobacillus paracasei ATCC 27139 shared a second prophage with both an INLAIN collection and a commercial Lactobacillus paracasei strains, whereas two collection strains shared a third one. On the other hand, mitomycin C-inducible prophages were detected only on about a half of the strains isolated from dairy products, which had (with only one exception) from moderate to high correlation coefficients according to RAPD-PCR fingerprinting. After induction, supernatants were filtered and tested against nine Lactobacillus strains of the set sensitive to previously assayed virulent phages, allowing isolation of two new virulent phages: ф iLp1308 and ф iLp84. Both phages were able to lyse all but one strains sensitive to previously assayed phage MLC-A.

At least 345 bacteriophages infecting Streptococcus thermophilus starter cultures have been isolated; general characteristics include high thermal resistance, short latent periods and large burst size. Phages with such characteristics are primed to thrive in the cheese making environment, lysing bacterial cultures and generating low-quality fermented products. All S. thermophilus phages isolated to date are members of the Siphoviridae family and the Caudovirales order and appear to constitute a polythetic phage species comprising two large groups, cos- and pac-types, based on the mode of DNA packaging. Comparative analyses have shown that S. thermophilus phage genomes are similarly organized into distinct modular regions and allow the detection of a core genome region. Several PCR-based techniques have been designed to detect them in cheese whey and milk samples. Similar S. thermophilus phages are globally distributed and endemic in specific dairy environments. The biogeography of S. thermophilus phages reinforces their current classification.

Aim: To ferment buttermilk, a low-cost by-product of the manufacture of butter, with a proteolytic strain of Lactobacillus helveticus, to enhance its value by the production of a functional peptide-enriched powder. Methods and Results: Buttermilk was fermented with Lact. helveticus 209, a strain chosen for its high proteolytic activity. To enhance the release of peptidic fractions, during fermentation pH was kept at 6 by using NaOH, Ca(CO)3 or Ca(OH)2. Cell-free supernatant was recovered by centrifugation, supplemented or not with maltodextrin and spray-dried. The profile of peptidic fractions released was studied by RP-HPLC. The lactose, Na and Ca content was also determined. The powder obtained was administered to BALB/c mice for 5 or 7 consecutive days, resulting in the proliferation of IgA-producing cells in the small intestine mucosa of the animals. Conclusions: Buttermilk is a suitable substrate for the fermentation with Lact. helveticus 209 and the release of peptide fractions able to be spray-dried and to modulate the gut mucosa in vivo. Significance and Impact of the Study: A powder enriched with peptides released from buttermilk proteins, with potential applications as a functional food additive, was obtained by spray-drying. A novel use of buttermilk as substrate for lactic fermentation is reported.

Lysogeny entails more economical and technological risks in probiotic Lactobacillus casei/paracasei bacteria than in other lactic acid bacteria, due to economic value. Lysogeny is widely spread among L. casei/paracasei strains. Siphophages C L 1 and C L 2, isolated from noninfected lysed-cultures of commercial L. paracasei A, are thermoresistant, have identical host spectrum, latent and burst times, whereas burst sizes are 148 and 85, respectively. Mitomycin C induction of L. paracasei A yielded prophage iA2, whose presence was confirmed on the strain genome and whose restriction patterns differed from phages C L 1 and C L 2. The latter shared several restriction fragments, probably indicating a common origin.