The present study is focused on the safety, technological characteristics, and probiotic evaluation of Enterococcus species from different artisanal raw milk dairy products, mainly cheeses with ...ripening. Apart from proteolytic and lipolytic activities, most enterococci show the ability to metabolize citrate and convert it to various aromatic compounds. Long-ripened cheeses therefore have a specific flavor that makes them different from cheeses produced from thermally treated milk with commercial starter cultures. In addition, enterococci are producers of bacteriocins effective against spoilage and pathogenic bacteria, so they can be used as food preservatives. However, the use of enterococci in the dairy industry should be approached with caution. Although originating from food, enterococci strains may carry various virulence factors and antibiotic-resistance genes and can have many adverse effects on human health. Still, despite their controversial status, the use of enterococci in the food industry is not strictly regulated since the existence of these so-called desirable and undesirable traits in enterococci is a strain-dependent characteristic. To be specific, the results of many studies showed that there are some enterococci strains that are safe for use as starter cultures or as probiotics since they do not carry virulence factors and antibiotic-resistance genes. These strains even exhibit strong health-promoting effects such as stimulation of the immune response, anti-inflammatory activity, hypocholesterolemic action, and usefulness in prevention/treatment of some diseases.
Genus Clostridium accompanies more than 200 known species and at least 30 among them are associated with human and animal diseases. At the moment, the treatment of clostridial infections is based on ...use of antibiotics. However, due to the European ban on the use of antibiotics in livestock production, novel therapeutic strategies for treatment of these hardly curable infections have been evaluated. Hence, in this study the antimicrobial effect of newly designed probiotic culture consisted of natural isolates Lactobacillus helveticus BGRA43, Lactobacillus fermentum BGHI14 and Streptococcus thermophilus BGVLJ1-44 against Clostridium difficile and Clostridium perfringens was analyzed.
The probiotic culture showed strong in vitro antimicrobial effect on C. difficile (human clinical isolate). In addition, individual strains and the probiotic combination exhibited immunomodulatory activity. The probiotic combination significantly increased the proliferation of GALT lymphocytes. At the other hand, none of the bacterial treatments (individual strains and the combination) induced the production of proinflammatory cytokines IL-6 and IL-1β by intestinal epithelial cells, Caco-2. Interestingly, Caco-2 cells exposed to the probiotic combination produced significantly elevated amount of TGFβ pointing to potential protecting effect of the probiotic. In addition, the results of field trial on spontaneously infected goats revealed reduction of C. perfringens in goats (below the detection threshold) after the probiotic treatment.
The results of this study indicated that the novel probiotic deserves to be further investigated as a promising antimicrobial agent against C. difficile and C. perfringens.
Mixed-mode dynamics is a complex type of dynamical behavior that has been observed both numerically and experimentally in numerous prototypical systems in the natural sciences. The compartmental ...Wilson-Callaway model for the dopaminergic neuron is an example of a system that exhibits a wide variety of mixed-mode patterns upon variation of a control parameter. One characteristic feature of this system is the presence of multiple time scales. In this article, we study the Wilson-Callaway model from a geometric point of view. We show that the observed mixed-mode dynamics is caused by a slowly varying canard structure. By appropriately transforming the model equations, we reduce them to an underlying three-dimensional canonical form that can be analyzed via a slight adaptation of the approach developed by M. Krupa, N. Popovic, and N. Kopell (unpublished).
Željeznička infrastruktura i željeznički promet tradicionalno su i povijesno od nacionalnog i strateškog interesa svake države, što objašnjava ponešto sporije liberalizacijske procese u odnosu na ...neke druge mrežne djelatnosti na zajedničkom tržištu Europske unije, kao što su primjerice elektroničke komunikacije. Prioritet Europske unije je ostvarenje zajedničkog europskog željezničkog područja (Single European Railway Area, SERA) kao načina dugoročnog osiguranja konkurentnosti željezničkog prometa. To je moguće pojednostavljenjem postupaka pružanja željezničkih prijevozničkih usluga, podizanjem kvalitete željezničkih i prijevozničkih usluga te uklanjanjem tržišnih neuspjeha koji mogu biti razlog neučinkovitog raspolaganja javnim sredstvima. Povećanje učinkovitosti željeznice moguće je otvaranjem tržišta za nove prijevoznike, za što je potrebno osigurati neovisnost upravitelja željezničke infrastrukture i upravitelja željezničkih uslužnih objekata. Navedeno se ostvaruje računovodstvenim razdvajanjem između upravitelja infrastrukture i željezničkih prijevoznika ako su oni vertikalno integrirani gospodarski subjekt, odnosno njihovim strukturnim razdvajanjem u zasebna trgovačka društva. EU je u posljednjih petnaestak godina donio tri pravna okvira kojima se ojačava uloga regulatornih tijela i osigurava jednak pravni položaj prijevoznika na tržištu osobito kroz neovisnost dodjele prometnih kapaciteta i određivanja naknada za njihovo korištenje. Uz navedeno, organiziraju se modeli sufinanciranja izgradnje nove i poboljšanja postojeće željezničke infrastrukture sredstvima EU fondova, podizanja interoperabilnosti i sigurnosti na razini EU-a, što bi trebalo olakšati prekogranični promet, osobito na dužim teretnim trasama, tzv. paneuropskim koridorima. Kombiniranje otvorenog pristupa nužnim željezničkim resursima i otvorenog javnog poziva za obavljanje usluga javnog prijevoza putnika omogućuje, sukladno stavovima koje zastupa Europska komisija, daljnje otvaranje tržišta kao što je već ostvareno u međunarodnom teretnom i putničkom prometu. Novi, četvrti željeznički okvir EU-a koji je u pripremi trebao bi povećati interes korisnika željezničkog prijevoza i učiniti tu prometnu granu konkurentnijom u odnosu na cestovni i zračni promet. Veći broj tržišnih takmaca trebao bi potaknuti produktivnost, specijalizaciju i inovativne poslovne modele uz veću uporabu informacijskih tehnologija. To bi trebalo doprinijeti povećanju putnika i tereta te novom zapošljavanju u željeznici i s njom povezanoj industriji.
Yogurt is a traditional fermented dairy product, prepared with starter cultures containing
and
that has gained widespread consumer acceptance as a healthy food. It is widely accepted that yogurt ...cultures have been recognized as probiotics, due to their beneficial effects on human health. In this study, we have characterized technological and health-promoting properties of autochthonous strains
BGKMJ1-36 and
BGVLJ1-21 isolated from artisanal sour milk and yogurt, respectively, in order to be used as functional yogurt starter cultures. Both BGKMJ1-36 and BGVLJ1-21 strains have the ability to form curd after five hours at 42 °C, hydrolyze α
, β
, and κ
casein, and to show antimicrobial activity toward
. The strain BGKMJ1-36 produces exopolysaccharides important for rheological properties of the yogurt. The colonies of BGKMJ1-36 and BGVLJ1-21 strains that successfully survived transit of the yogurt through simulated gastrointestinal tract conditions have been tested for adhesion to intestinal epithelial Caco-2 cells. The results reveal that both strains adhere to Caco-2 cells and significantly upregulate the expression of autophagy-, tight junction proteins-, and anti-microbial peptides-related genes. Hence, both strains may be interesting for use as a novel functional starter culture for production of added-value yogurt with health-promoting properties.
The aim of this study was to test the suitability of three different ancient wheat varieties (emmer, spelt and khorasan) to produce spontaneously fermented sourdough bread and to evaluate the impact ...on the dough rheological properties, ultrastructure and baking quality. Modern wheat sourdough bread and bakery yeast fermented bread were used as controls. Sourdoughs produced from modern and ancient wheats exerted different effects on dough viscoelastic properties, bread specific volume, texture, firming rate, colour and sensory properties, while there was no influence on bread water activity. Both khorasan sourdough, being characterised with the highest dough strength and dense gluten protein matrix, and emmer sourdough, with loose and thin gluten strands of low strength, yielded breads characterised by low specific volume and hard crumb texture. Spelt and modern wheat sourdough were characterised by foam-like dough structures with entrapped gas cells leading to breads of similar specific volume and texture. Although the yeast-fermented wheat flour exerted a higher specific volume and the lowest firmness, the sourdough wheat flour bread had a lower firming rate. A comparison of sourdough bread prepared with modern and ancient wheats revealed that breads based on ancient varieties possess a less noticeable sour taste, odour and flavour, thus contributing to more sensory-appealing sourdough bread.
This study aimed to explore the probiogenomic characteristics of artisanal bacteriocin-producing
BGZLM1-5 and its potential application in reducing
in a milk model. The BGZLM1-5 strain was isolated ...from raw cow's milk from households in the Zlatar Mountain region. The whole genome sequencing approach and bioinformatics analyses reveal that the strain BGZLM1-5 is non-pathogenic to humans. Bacteriocin-containing supernatant was thermally stable and antimicrobial activity retained 75% of the initial activity compared with that of the control after treatment at 90 °C for 30 min. Antimicrobial activity maintained relative stability at pH 3-11 and retained 62.5% of the initial activity compared with that of the control after treatment at pH 1, 2, and 12. The highest activity of the partially purified bacteriocin was obtained after precipitation at 40% saturation with ammonium sulfate and further purification by mixing with chloroform. Applying 3% and 5% (
) of the bacteriocin-containing supernatant and 0.5% (
/
) of the partially purified bacteriocin decreased the viable number of
ATCC19111 after three days of milk storage by 23.5%, 63.5%, and 58.9%, respectively.
We investigate the effects of a Heaviside cutoff on the dynamics of traveling fronts in a family of scalar reaction-diffusion equations with degenerate polynomial potential that includes the ...classical Zeldovich equation. We prove the existence and uniqueness of front solutions in the presence of the cutoff, and we derive the leading-order asymptotics of the corresponding propagation speed in terms of the cutoff parameter. For the Zeldovich equation, an explicit solution to the equation without cutoff is known, which allows us to calculate higher-order terms in the resulting expansion for the front speed; in particular, we prove the occurrence of logarithmic (switchback) terms in that case. Our analysis relies on geometric methods from dynamical systems theory and, in particular, on the desingularization technique known as ‘blow-up.’
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