Procjena probiotičkih svojstava bakterije Enterococcus mundtii, njezino preživljavanje u bozi i proizvodnja bakteriocina in situ

Boza is a low-pH and low-alcohol cereal-based beverage produced in the Balkan Peninsula. Barley was cooked and prepared according to a traditional recipe and inoculated with Enterococcus mundtii ST4V (a potential probiotic and bacteriocin-producing strain), commercially produced boza, Saccharomyces cerevisiae, and a combination of strain E. mundtii ST4V and Saccharomyces cerevisiae. Fermentation was carried out at 37 °C for 3 h. The organoleptic properties of fermented products were evaluated by a qualified taste panel. No significant differences in rheological properties were observed, suggesting that E. mundtii ST4V had no effect on the quality of the final product. Microbial cell numbers remained relatively unchanged during one week of storage. The preservative properties of bacteriocin ST4V were evaluated by contaminating boza with Lactobacillus sakei DSM 20017. Changes in microbial populations were monitored by using classical microbiological methods, PCR with species-specific primers and denaturing gradient gel electrophoresis (DGGE). Adsorption of bacteriocin ST4V to target cells is pH-dependent, with the highest adsorption (88 %) recorded at pH=8.0 and pH=10.0. Maximum adsorption of bacteriocin ST4V (75 %) to Enterococcus faecalis and Listeria innocua was recorded at 25 to 37 °C. Growth of E. mundtii ST4V was inhibited only by a few antibiotics and anti-inflammatory medicaments, suggesting that the strain may be used as a probiotic by individuals receiving medical treatment.Boza je napitak od žitarica, male pH-vrijednosti i neznatnog udjela alkohola, koji se priprema na Balkanu. U istraživanju je upotrijebljena boza pripremljena kuhanjem ječma prema tradicionalnom receptu, inokulirana bakterijskim sojem Enterococcus mundtii ST4V (koji proizvodi bakteriocin i ima probiotička svojstva), bozom proizvedenom na komercijalan način, kvascem Saccharomyces cerevisiae i kombinacijom bakterijskog soja i kvasca. Tim stručnjaka ispitao je organoleptička svojstva proizvoda dobivenih nakon 3 sata fermentacije pri 37 ºC. Nije utvrđena značajna razlika u reološkim svojstvima dobivenih proizvoda, što upućuje na zaključak da inokulacija sojem E. mundtii ST4V nije utjecala na kakvoću proizvoda. Čak ni nakon tjedan dana skladištenja nije se promijenio broj stanica mikroorganizama u proizvodima. Da bi se procijenio zaštitni učinak bakteriocina ST4V, ispitana je boza inokulirana sojem Lactobacillus sakei DSM 20017, pa je mikrobna populacija praćena klasičnim mikrobiološkim metodama, reakcijom polimeraze (PCR) sa specifičnim početnicama i elektroforezom u gradijentu denaturirajućega gela (DGGE). Adsorpcija bakteriocina ST4V na ciljane stanice ovisi o pH-vrijednosti, s najvećom adsorpcijom (88 %) zabilježenom pri pH=8 i pH=10. Maksimalna adsorpcija bakteriocina (75 %) na stanice Enterococcus faecalis i Listeria innocua zabilježena je u rasponu temperature od 25 do 37 ºC. Rast bakterije E. mundtii ST4V inhibirali su samo neki antibiotici i protuupalni lijekovi, što upućuje na to da taj soj ima probiotički učinak i na pacijente koji primaju određenu terapiju

Quantitative Structure–Property Relationship Studies on Ostwald Solubility and Partition Coefficients of Organic Solutes in Ionic Liquids

Article discussing quantitative structure-property relationship studies on Ostwald solubility and partition coefficients of organic solutes in ionic liquids

Deletion of a Csf1r enhancer selectively impacts CSF1R expression and development of tissue macrophage populations.

The proliferation, differentiation and survival of mononuclear phagocytes depend on signals from the receptor for macrophage colony-stimulating factor, CSF1R. The mammalian Csf1r locus contains a highly conserved super-enhancer, the fms-intronic regulatory element (FIRE). Here we show that genomic deletion of FIRE in mice selectively impacts CSF1R expression and tissue macrophage development in specific tissues. Deletion of FIRE ablates macrophage development from murine embryonic stem cells. Csf1r mice lack macrophages in the embryo, brain microglia and resident macrophages in the skin, kidney, heart and peritoneum. The homeostasis of other macrophage populations and monocytes is unaffected, but monocytes and their progenitors in bone marrow lack surface CSF1R. Finally, Csf1r mice are healthy and fertile without the growth, neurological or developmental abnormalities reported in Csf1r rodents. Csf1r mice thus provide a model to explore the homeostatic, physiological and immunological functions of tissue-specific macrophage populations in adult animals

Study of quasi-monophase Y-type hexaferrite Ba2Mg2Fe12O22 powder

We present the structural and magnetic properties of a multiferroic Ba2Mg2Fe12O22 hexaferrite composite containing a small amount of MgFe2O4. The composite material was obtained by auto-combustion synthesis and, alternatively, by co-precipitation. The Ba2Mg2Fe12O22 particles obtained by co-precipitation have an almost perfect hexagonal shape in contrast with those prepared by auto-combustion. Two magnetic phase transitions, responsible for the composite’s multiferroic properties, were observed, namely, at 183 K and 40 K for the material produced by auto-combustion, and at 196 K and 30 K for the sample prepared by co-precipitation. No magnetic phase transitions in these temperature ranges were observed for a MgFe2O4 sample, which shows that the magnesium ferrite does not affect the multiferroic properties of this type of multiferroic metarials

Bacteriocinogenic Lactococcus lactis subsp: lactis DF04Mi isolated from goat milk: Evaluation of the probiotic potential

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its probiotic potential. Lc. lactis DF4Mi was resistant to acidic pH and oxbile, presented co-aggregation with Listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensitive to most tested antibiotics. These properties indicate that this Lc. lactis strain can be used for enhancement of dairy foods safety and quality, in combination with potential probiotic properties

The two faces of leuconostoc mesenteroides in food systems

Leuconostoc mesenteroides is a lactic acid bacterium (LAB) that has been isolated from different sources. Some of its strains are able to produce bacteriocins, and most of them belong to class IIa and shows anti-Listeria activity. Additionally, Lc. mesenteroides species can be a probiotic candidate; promising studies have shown the potential of this species to survive and grow under various stress conditions present in the gastrointestinal tract. On the other hand, this microorganism can cause spoilage in some types of food matrices, and scarce reports have shown the pathogenic potential of this species. In this review, we focus on an overview of Lc. mesenteroides bacteriocin-producing strains and their probiotic potential, in contrast with Lc. mesenteroides spoilage and pathogenic cases reported in the literature.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES