1,721,061 research outputs found
Identification of Bifidobacteria by the Phosphoketolase Assay
No full textBifidobacteria are commensal bacteria, which naturally colonize the gastrointestinal tract of a large number of animals, including humans, contributing to their health and well-being. An important taxonomic marker for the identification of members of the bifidobacterial group is the presence of the fructose-6-phosphate phosphoketolase (F6PPK) activity. The F6PPK enzyme is involved in the bifidus shunt based on the ability of F6PPK to split fructose-6-phosphate into erythrose-4-phosphate and acetyl phosphate. Here, we describe the two main methods utilized to detect the presence of F6PPK activity, that is, the enzymatic assay and the presence of the D-xylulose-5-phosphate/fructose-6-phosphate phosphoketolase bifidobacterial gene
Possible application in food industry of a recently isolated exopolysaccharydes producing bifidobacterial species
No full textHealth awareness among consumers have recently generated more demands for low-fat or fat-free
dairy products. However, since milk fat contrìbutes to the flavor, body and texture development
of the dairy products, removal leads to textural and functional defects in low fat fermented milk
products. ln this perspective, the exopolysaccharides (EPS) produced by food grade lactic acid
bacteria (LAB) have gained much importance as biothickeners and texturizers. EPS producing LAB as
'biothickeners' should offer natural, more acceptable and a preferred approach to many additives.
EPS ìmpart highly desirable rheological changes in the food matrix such as increased viscosity,
improved texture and reduced syneresis. Further, EPS may ìnduce positive physiological responses
ìncludìng lower cholesterol levels, reduced formation of pathogenic biofilms, modulation of adhesion
to epithelial cells and increased levels of bifidobacterio showing a prebiotic potential. Hence, the
choice of EPS producing starter cultures seems to give several advantages over nonproducing
ones. Bifidobocterium aesculapi, a novel species recently described, resulted able to ferment
lactose as well as producing an exocellular gelling matrix, which was identified and quantified as
EPS. Seven strains of B. aesculapii and the type strains of the two related species 8. stellenboschense
and B. scardovii were tested for their abilìty to ferment whoìe milk. Texture parameters (Textureanalyzer),
volatile aromatic compounds (detected by GC/MS-So|id Phase Micro Exraction) and pH
were assayed. B. aesculapii strains fermented whole milk conferring to the obtained products the
highest viscosity index, hardness, consistency and cohesiveness values. The volatile profiles showed
quali-quantitative differences among the samples and, from a sensoriaI point of view, they represent
a specific product fingerprinting. However, 2,3 butanedione, 3-hyd roxy-2-buta none, 2-butanone,
propanone and acetic acid were the most representative detected molecules. The data obtained
suggest that B. aesculapii, belonging to probiotic bacteria, should be tested for further application
in food ìndustry
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Bifidobacterium xylocopae sp. nov. and Bifidobacterium aemilianum sp. nov., from the carpenter bee (Xylocopa violacea) digestive tract
Full text linkSocial bees harbor a community of gut mutualistic bacteria, among which bifidobacteria occupy an important niche. Recently, four novel species have been isolated from guts of different bumblebees, thus allowing to suppose that a core bifidobacterial population may be present in wild solitary bees. To date there is sparse information about bifidobacteria in solitary bees such as Xylocopa and Osmia spp., this study is therefore focused on the isolation and characterization of bifidobacterial strains from solitary bees, in particular carpenter bee (Xylocopa violacea), builder bee (Osmia cornuta), and red mason bee (Osmia rufa). Among the isolates from Osmia spp. no new species have been detected whereas among Xylocopa isolates four strains (XV2, XV4, XV10, XV16) belonging to putative new species were found. Isolated strains are Gram-positive, lactate- and acetate-producing and possess the fructose-6-phosphate phosphoketolase enzyme. Full genome sequencing and genome annotation were performed for XV2 and XV10. Phylogenetic relationships were determined using partial and complete 16S rRNA sequences and hsp60 restriction analysis that confirmed the belonging of the new strains to Bifidobacterium genus and the relatedness of the strains XV2 and XV10 with XV16 and XV4, respectively. Phenotypic tests were performed for the proposed type strains, reference strains and their closest neighbor in the phylogenetic tree. The results support the proposal of two novel species Bifidobacterium xylocopae sp. nov. whose type strain is XV2 (=DSM 104955T = LMG 30142T), reference strain XV16 and Bifidobacterium aemilianum sp. nov. whose type strain is XV10 (=DSM 104956T = LMG 30143T), reference strain XV4
First evidence of the presence of bifidobacteria in Chiroptera (Rousettus aegyptiacus)
No full textAim of the present work is to Investigate Bifidobacteria biodiversity in a particular species of bats, the Rousettus aegyptyacus.
They are frugivores, preferring to eat the pulp and juice of very ripe fruit and are found throughout Africa south of the Sahara, in Egypt, and on the coastlines of the Arabian Peninsul
POTENZIALE ASSOCIAZIONE DI TTO E PROBIOTICI NEL TRATTAMENTO DELLE CANDIDOSI: STUDI IN VITRO E IN VIVO
No full textIn questo studio clinico, all’azione antimicotica e antibatterica dell’olio essenziale di
Melaleuca alternifolia, più noto come Tea tree, si unisce quella dei lattobacilli, i quali sono in grado
di contrastare la colonizzazione del microbiota vaginale da parte dei ceppi di Candida. Una nuova
associazione sinergica che presenta interessanti prospettive di utilizzo per il benessere delle donn
Lactobacilli and yeasts for phytate degradation in soy milk fermented products
No full textDue to the increasing prevalence of dairy intolerance and the adoption of vegan/vegetarian diets,
there is a growing demand for non-dairy alternatives. One commonly used substitute in vegetarian
and vegan food products is soybean, which provides minerals and proteins. However, soybean also
contains the antinutrient phytate (inositol hexaphosphate, IP6), which hinders nutrient absorption.
To address this, microbial phytases, which are enzymes hydrolyzing phosphate groups from IP6,
have gained significant attention. Degradation of IP6 releases chelated minerals, such as Fe and Zn,
and solubilize IP6, resulting in increased mineral availability for intestinal absorption.
The aim of the present study was to investigate 10 Lactic Acid Bacteria belonging to
Lacticaseibacillus casei, Lactobacillus delbruecki, L. helveticus, and Lactiplantibacillus plantarum,
and 22 yeasts, previously isolated from Tajikistan yogurt and togwa (Tanzanian traditional
fermented cereal- and cassava-based product) for i) fermentation capacity (singularly or in mixed
cultures) of soy milk and ii) phytase activity. All strains belonging to Lacticaseibacillus casei showed
the ability to ferment soy milk and thicken the product. With respect to the yeasts, Kluvieromyces
marxianus and Pichia kudriavzevii were selected. The previously observed strong phytate degrading
ability of strain P. kudriavzevii TY1322 in vitro trials was confirmed in this study during soymilk
fermentation. The phytate degradation was further improved when strain P. kudriavzevii TY1322
was used in co-culture with Lactobacillus casei AB3 and K. marxianus AL3 or BL8 suggesting these
strains as promising candidates for phytate degradation in soy-based food fermentation
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