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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
TB Knowledgebase: Interactive application for extracting knowledge from the TB literature to inform TB drug and vaccine development
Full text linkData mining and literature mining with biological data integration to create an interactive knowledge base for tuberculosis
Bifidobacterium aerophilum sp. nov., Bifidobacterium avesanii sp. nov. and Bifidobacterium ramosum sp. nov.: Three novel taxa from the faeces of cotton-top tamarin (Saguinus oedipus L.)
No full textForty-five microorganisms were isolated on bifidobacteria selective medium from one faecal sample of an adult subject of the cotton-top tamarin (Saguinus oedipus L.). All isolates were Gram-positive, catalase-negative, anaerobic, fructose-6-phosphate phosphoketolase positive, and asporogenous rod-shaped bacteria. In this study, only eight out of the forty-five strains were characterized more deeply, whereas the others are still currently under investigation. They were grouped by BOX-PCR into three clusters: Cluster I (TRE 17T, TRE 7, TRE 26, TRE 32, TRE 33, TRE I), Cluster II (TRE CT), and Cluster III (TRE MT). Comparative analysis of 16S rRNA gene sequences confirmed the results from the cluster analysis and revealed relatively low level similarities to each other (mean value 95%) and to members of the genus Bifidobacterium. All eight isolates showed the highest level of 16S rRNA gene sequence similarities with Bifidobacterium scardovii DSM 13734T (mean value 96.6%). Multilocus sequence analysis (MLSA) of five housekeeping genes (hsp60, rpoB, clpC, dnaJ and dnaG) supported their independent phylogenetic position to each other and to related species of Bifidobacterium. The G + C contents were 63.2%, 65.9% and 63.0% for Cluster I, Cluster II and Cluster III, respectively. Peptidoglycan types were A3α l-Lys-l-Thr-l-Ala, A4β l-Orn (Lys)-d-Ser-d-Glu and A3β l-Orn-l-Ser-l-Ala in Clusters I, II and III, respectively. Based on the data provided, each cluster represented a novel taxon for which the names Bifidobacterium aerophilum sp. nov. (TRE 17T = DSM 100689 = JCM 30941; TRE 26 = DSM 100690 = JCM 30942), Bifidobacterium avesanii sp. nov. (TRE CT = DSM 100685 = JCM 30943) and Bifidobacterium ramosum sp. nov. (TRE M = DSM 100688 = JCM 30944) are proposed
Bifidobacterium myosotis sp. Nov., Bifidobacterium tissieri sp. nov. and Bifidobacterium hapali sp. nov., isolated from faeces of baby common marmosets (Callithrix jacchus L.)
No full textIn a previous study on bifidobacterial distribution in New World monkeys, six strains belonging to the Bifidobacteriaceae were isolated from faecal samples of baby common marmosets (Callithrix jacchus L.). All the isolates were Gram-positive-staining, anaerobic, asporogenous and fructose-6-phosphate phosphoketolase-positive. Comparative analysis of 16S rRNA gene sequences revealed relatively low levels of similarity (maximum identity 96 %) to members of the genus Bifidobacterium, and placed the isolates in three independent clusters: strains of cluster I (MRM_5.9T and MRM_5.10) and cluster III (MRM_5.18T and MRM_9.02) respectively showed 96.4 and 96.7 % 16S rRNA gene sequence similarity to Bifidobacterium callitrichos DSM 23973T, while strains of cluster II (MRM_8.14T and MRM_9.14) showed 95.4 % similarity to Bifidobacterium stellenboschense DSM 23968T. Phylogenetic analysis of partial hsp60 and clpC gene sequences supported an independent phylogenetic position of each cluster from each other and from the related type strains B. callitrichos DSM 23973T and B. stellenboschense DSM 23968T. Clusters I, II and III respectively showed DNA G+C contents of 64.9-65.1, 56.4-56.7 and 63.1-63.7 mol%. The major cellular fatty acids of MRM_5.9T were C14 : 0, C16 : 0 and C18 : 1ω9c dimethylacetal, while C16 : 0 was prominent in strains MRM_5.18T and MRM_8.14T, followed by C18 : 1ω9c and C14 : 0. Biochemical profiles and growth parameters were recorded for all the isolates. Based on the data provided, the clusters represent three novel species, for which the names Bifidobacterium myosotis sp. nov. (type strain MRM_5.9T = DSM 100196T = JCM 30796T), Bifidobacterium hapali sp. nov. (type strain MRM_8.14T = DSM 100202T = JCM 30799T) and Bifidobacterium tissieri sp. nov. (type strain MRM_5.18T = DSM 100201T = JCM 30798T) are proposed
Bifidobacterium primatium sp. nov., Bifidobacterium scaligerum sp. nov., Bifidobacterium felsineum sp. nov. and Bifidobacterium simiarum sp. nov.: Four novel taxa isolated from the faeces of the cotton top tamarin (Saguinus oedipus) and the emperor tamarin (Saguinus imperator)
No full textFour novel Gram-stain-positive, non spore forming and fructose-6-phosphate phosphoketolase-positive strains were isolated from the faeces of a cotton top tamarin (Saguinus oedipus) and an emperor tamarin (Saguinus imperator). Phylogenetic analyses based on 16S rRNA revealed that bifidobacterial strains TRE 1T exhibit close phylogenetic relatedness to Bifidobacterium catulorum DSM 103154 (96.0%) and Bifidobacterium tissieri DSM 100201 (96.0%); TRE DT and TRE HT were closely related to Bifidobacterium longum subsp. longum ATCC 15708T with similarity values of 97.4% and 97.5%, respectively; TRI 7T was closely related to Bifidobacterium tissieri DSM 100201 (96.0%). The Average Nucleotide Identity (ANI) and in silico DDH (isDDH) analysis with closest neighbour supported an independent phylogenetic position of all strains with values ranged from 74 to 85% for ANI and from 24 to 28% for isDDH. DNA base composition of the four strains was in the range of 58.3–63.5 mol% G + C. Based on the phylogenetic, genotypic and phenotypic data, the strains TRE 1T, TRE DT, TRE HT and TRI 7T clearly represent four novel taxa within the genus Bifidobacterium for which the names Bifidobacterium primatium sp. nov. (type strain TRE 1T = DSM 100687T = JCM 30945T), Bifidobacterium scaligerum sp. nov. (type strain TRE DT = DSM 103140T = JCM 31792T), Bifidobacterium felsineum sp. nov. (type strain TRE HT = DSM 103139T = JCM 31789T) and Bifidobacterium simiarum sp. nov. (type strain TRI 7T = DSM 103153T = JCM 31793) are proposed
In silico RFLP Analysis of 16S rRNA Genes: A Helpful Application for Distinguishing Bifidobacteria from Human and Animal Source
Full text linkBifidobacterial species are widespread in gastrointestinal tracts of mammalian and other animals; they can be found in extra body environment only after a fecal contamination or human intentional addition (as the case of probiotics). Interestingly their occurrence is strictly linked to their hosts with a clear demarcation between animal and human species. PCR-restriction fragment length polymorphism (PCR-RFLP) on the 16S rRNA gene, using Alul, and TaqI restriction enzymes, have been utilized to distinguish the animal or human source of 64 strains belonging to 13 Bifidobacterium species (Delcenserie et al. [15]). Our aim was to test this method updating an in silico restriction analysis on the available 16S rRNA gene sequences of all 55 currently described taxa of Bifidobacterium genus. Our results confirmed the reliability of this method, optimized with the use of three restriction enzymes: Alul, TaqI and MaeIII, as a fast and simple strategy to determine the origin (human or animal) of bifidobacteria. Interestingly, the bifidobacterial species recently isolated from non-human primates cluster in the group of animal source except the bifidobacterial species isolated from higher non-human primates closest to humans such as apes (chimpanzee, orangutan and gorilla) that clusters with human group. Moreover, B. minimum, B. subtile and B. mongoliense isolated only from extrabody environment of which the source is unknown clustered with animal species. The in silico RFLP-PCR confirmed its powerful ability to attribute the primary source of occurrence (human or animal) for bifidobacterial species to the human or animal habitat
Bifidobacterium catulorum sp. nov., a novel taxon from the faeces of the baby common marmoset (Callithrix jacchus)
No full textIn our previous study based on hsp60 PCR-restriction fragment length polymorphism and 16S rRNA gene sequencing, we stated that the bifidobacterial strains isolated from the individual faecal samples of five baby common marmosets constituted different phylogenetically isolated groups of the genus Bifidobacterium. In that study, we also proposed that these isolated groups potentially represented novel species of the genus Bifidobacterium. Out of them, Bifidobacterium aesculapii, Bifidobacterium myosotis, Bifidobacterium tissieri and Bifidobacterium hapali, have been described recently. Another strain, designated MRM 8.19T, has been classified as member of the genus Bifidobacterium on the basis of positive results for fructose-6-phosphate phosphoketolase activity and analysis of partial 16S rRNA, hsp60, clpC, dnaJ, dnaG and rpoB gene sequences. Analysis of 16S rRNA and hsp60 gene sequences revealed that strain MRM 8.19T was related to B. tissieri DSM 100201T (95.8 %) and to Bifidobacterium bifidum ATCC 29521T (93.7 %), respectively. The DNA G+C composition was 63.7 mol% and the peptidoglycan structure was l-Orn(Lys)-l-Ser. Based on the phylogenetic, genotypic and phenotypic data reported, strain MRM 8.19T represents a novel taxon within the genus Bifidobacterium for which the name Bifidobacterium catulorum sp. nov. (type strain MRM 8.19T=DSM 103154T=JCM 31794T) is proposed
Bifidobacterium. eulemuris sp. nov. isolated from the faeces of the black lemur (Eulemur macaco)
No full textForty strains of bifidobacteria were isolated from the faeces of two adult subjects of black lemur, Eulemur macaco. Twenty-five were identified as Bifidobacterium lemurum, the novel species recently described in Lemur catta. All other isolates resulted Gram-positive-staining, non-spore-forming, fructose-6-phosphate phosphoketolase positive, microaerophilic, irregular rod-shaped bacteria that often resembled Y or V shapes cells. Typing techniques revealed these isolates were nearly identical and strain LMM_E3T was chosen as representative and characterized further. Phylogenetic analysis based on 16S rRNA gene sequences clustered this isolate inside the genus Bifidobacterium and showed the highest levels of sequence similarities with Bifidobacterium lemurum DSM 28807T (99.6%), with Bifidobacterium pullorum LMG 21816T and Bifidobacterium longum subsp. infantis ATCC 15697T (96.4 % and 96.3%, respectively). Analysis of hsp60 gene sequences revealed that strain LMM_E3T was also closely related to Bifidobacterium stellenboschense DSM 23968T (93.3%). DNA-DNA reassociation value with the closest neighbour B. lemurum DSM 28807T was found to be 65.4%. The DNA base composition was 62.3 mol% G+C. Strain LMM_E3T showed a peptidoglycan structure which has not been detected in bifidobacteria so far: A3α L-Lys - L-Ser - L-Thr - L-Ala. Based on the phylogenetic, genotypic and phenotypic data, strain LMM_E3 T represents a novel species within the genus Bifidobacterium for which the name Bifidobacterium eulemuris sp. nov. is now proposed; the type strain is LMM_E3T (=DSM 100216T; = JCM 30801T)
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
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