1,720,963 research outputs found
Safety, functionality and genomic assessment of Pediococcus acidilactici strains isolated from traditional Persian fermented products with potential probiotic properties and hypocholesterolemic effect
No full textPediococcus acidilactici has a good reputation for its technological properties, particularly in the production of
fermented sausages and has also been considered as a potential probiotic species. Since in recent years there is
an increasing demand for probiotics of non-dairy origin, assessing bacterial species from non-dairy environments
could be pretty advantageous. In this study, different lactic acid bacteria (LAB) were isolated from a traditional
Persian food (Kashk Zard), and strains discrimination was carried out by RAPD-PCR. Subsequently, some strains were
identified to the species level and evaluated for their safety and functionality as probiotics, including properties such
as antimicrobial activity, resistance to simulated human gastrointestinal conditions, and cholesterol-lowering effects.
The genome of P. acidilactici strain IRZ12B was sequenced and the in silico analysis revealed that this strain possesses
interesting probiotic properties, such as cholesterol-lowering capability and antimicrobial activitiy. Furthermore,
genome analysis confirmed the absence of transmissible antibiotic resistance genes, plasmids, and virulence factors
inside the genome. The results reported in this study make P. acidilactici IRZ12B a promising potential probiotic strain
to be considered for the production of novel non-dairy-based functional food
Genomic and Phenotypic Evaluation of Potential Probiotic Pediococcus Strains with Hypocholesterolemic Effect Isolated from Traditional Fermented Food
No full textThe use of probiotic microorganisms in food with the aim to confer health benefits to the host is one of the most critical roles of functional foods. Many pediococci bacteria frequently related to the meat environment, have technological properties, and are therefore commercially used as starter in the production of fermented meat products, such as different types of sausages. In this study, different lactic acid bacteria were isolated, identified to the species level, and then evaluated for their safety and functionality as possible probiotics. Different properties, such as resistance to simulated human gastrointestinal conditions, antimicrobial activity, and cholesterol-lowering effects, have been studied. Finally, the complete genome of one strain, namely P. acidilactici IRZ12B, which showed interesting features as a promising probiotic candidate, was sequenced and further studied. The results revealed that IRZ12B possesses interesting probiotic properties, particularly cholesterol-lowering capability and antimicrobial activity. In silico analysis evidenced the absence of plasmids, transmissible antibiotic resistance genes, and virulence factors. We also detected a bacteriocin encoding gene and a cholesterol assimilation-related protein. The phenotypical and genomic outcomes described in this study make P. acidilactici IRZ12B a very interesting cholesterol-lowering potential probiotic strain to be considered for the development of novel non-dairy-based functional foods
Effects of 2′-fucosyllactose-based encapsulation on probiotic properties in streptococcus thermophilus
Get PDFStreptococcus thermophilus is widely used in dairy fermentation as a starter culture for yogurt and cheese production. Many strains are endowed with potential probiotic properties; however, since they might not survive in adequate amounts after transit through the human gastrointestinal tract, it is advisable to improve cell survivability during this passage. The present study evaluates the use of 2′-fucosyllactose, a prebiotic molecule from human milk, compared with other known molecules, such as gelatin and inulin, to form alginate-based microcapsules to fulfill these requirements. Such microcapsules, obtained by the extrusion technique, were evaluated in terms of encapsulation efficiency, storage stability, gastrointestinal condition resistance, and cell release kinetics. Results reveal that microcapsules made using 2′-fucosyllactose and those with inulin resulted in the most efficient structure to protect S. thermophilus strain TH982 under simulated gastrointestinal conditions (less than 0.45 log CFU/g decrease for both agents). In addition, a prompt and abundant release of encapsulated cells was detected after only 30 min from microcapsules made with sodium alginate plus 2′-fucosyllactose in simulated gastrointestinal fluid (more than 90% of the cells). These encouraging results represent the first report on the effects of 2′-fucosyllactose used as a co-encapsulating agent
Identification and transferability of tetracycline resistance in streptococcus thermophilus during milk fermentation, storage, and gastrointestinal transit
Get PDFThe existence of antibiotic-resistant bacteria in food products, particularly those carrying acquired resistance genes, has increased concerns about the transmission of these genes from benefi-cial microbes to human pathogens. In this study, we evaluated the antibiotic resistance-susceptibility patterns of 16 antibiotics in eight S. thermophilus strains, whose genome sequence is available, using phenotypic and genomic approaches. The minimal inhibitory concentration values collected revealed intermediate resistance to aminoglycosides, whereas susceptibility was detected for different classes of β-lactams, quinolones, glycopeptide, macrolides, and sulfonamides in all strains. A high tetracycline resistance level has been detected in strain M17PTZA496, whose genome analysis indicated the presence of the tet(S) gene and the multidrug and toxic compound extrusion (MATE) family efflux pump. Moreover, an in-depth genomic analysis revealed genomic islands and an integrative and mobilizable element (IME) in the proximity of the gene tet(S). However, despite the presence of a prophage, genomic islands, and IME, no horizontal gene transfer was detected to Lactobacil-lus delbrueckii subsp. lactis DSM 20355 and Lactobacillus rhamnosus GG during 24 h of skim milk fermentation, 2 weeks of refrigerated storage, and 4 h of simulated gastrointestinal transit
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Limosilactobacillus fermentum ING8, a Potential Multifunctional Non-Starter Strain with Relevant Technological Properties and Antimicrobial Activity
Get PDFLactic acid bacteria (LAB) have gained particular attention among different exopolysaccharide-producing microorganisms due to their safety status and effects on human health and food production. Exopolysaccharide-producing LAB play a crucial role in different ways, such as improving texture, mouthfeel, controlling viscosity, and for low-calorie food production. In this study, we isolated a mul-tifunctional strain with good exopolysaccharide production properties. Limosilactobacillus fermentum ING8 was isolated from an Indian traditional fermented milk (Dahi) and evaluated for its safety, enzymatic activity, NaCl resistance and temperature tolerance, milk coagulation, and storage stability. Finally, the complete genome of this strain was sequenced and subjected to safety in silico evaluation and genomic analysis. The results revealed that L. fermentum ING8 possesses relevant technological properties, such as exopolysaccharide production, antimicrobial activity, and galactose utilization. Besides, this strain showed very high stability to storage conditions at refrigeration temperature. In addition, the genomic analysis did not evidence any possible deleterious elements, such as acquired antibiotic resistance genes, virulence genes, or hemolysis-related genes. However, all structural genes related to the galactose operon and EPS production were detected. Therefore, L. fermentum ING8 can be considered a promising multifunctional bacterium to be proposed as non-starter in different types of dairy productions
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Thermal resistance and high-performance microwave decontamination assessment of Bacillus endospores isolated from food-grade herbal extracts
Get PDFGenerally, endospore contamination can occur from different sources during product manufacturing in many industries and therefore lower its quality by affecting physicochemical properties and shelf-life. Bacterial endospores can germinate inside the product and produce several enzymes, which can cause several undesirable changes. This study assessed the spores thermal resistance and applied a microwave decontamination technique toward herbal extracts (Tilia tomentosa and Centella asiatica) containing ethanol or glycerol. Based on 16S rRNA analysis, the detected contaminant endospores belonged to different Bacillus species, namely B. subtilis, B. zhangzhouensis, and B. pumilus. The thermal resistance assessment using inoculated endospores in the actual products revealed B. pumilus T2 as the most resistant endospore to the heat treatments tested in both T. tomentosa and C. asiatica extracts. Finally, a high-performance microwave technique was used to decontaminate T. tomentosa extract against the mixture of Bacillus spores. Results from the microwave technique indicate that the increase of temperature from 100°C to 105°C not only decontaminated the product but also could dramatically decrease the effective thermal treatment time (10 times), which can benefit the product quality. The results provided in this study considerably contribute to improving an original decontamination method for products containing glycerol and ethanol with the most negligible effect on product quality
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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