scholarly journals Analysis of the Fecal Microflora of Human Subjects Consuming a Probiotic Product Containing Lactobacillus rhamnosusDR20

2000 ◽  
Vol 66 (6) ◽  
pp. 2578-2588 ◽  
Author(s):  
G. W. Tannock ◽  
K. Munro ◽  
H. J. M. Harmsen ◽  
G. W. Welling ◽  
J. Smart ◽  
...  
Keyword(s):  
16S Rrna ◽  
Gel Electrophoresis ◽  
Control Period ◽  
Test Period ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Gas Liquid Chromatography ◽  
Milk Product ◽  
Fecal Microflora ◽  
V3 Region

ABSTRACT The composition of the fecal microflora of 10 healthy subjects was monitored before (6-month control period), during (6-month test period), and after (3-month posttest period) the administration of a milk product containing Lactobacillus rhamnosus DR20 (daily dose, 1.6 × 109 lactobacilli). Monthly fecal samples were examined by a variety of methods, including bacteriological culture analysis, fluorescent in situ hybridization with group-specific DNA probes, denaturing gradient gel electrophoresis of the V2-V3 region of 16S rRNA genes amplified by PCR, gas-liquid chromatography, and bacterial enzyme activity analysis. The composition of theLactobacillus population of each subject was analyzed by pulsed-field gel electrophoresis of bacterial DNA digests in order to differentiate between DR20 and other strains present in the samples. Representative isolates of lactobacilli were identified to the species level by sequencing the V2-V3 region of their 16S rRNA genes and comparing the sequences obtained (BLAST search) to sequences in the GenBank database. DR20 was detected in the feces of all of the subjects during the test period, but at different frequencies. The presence of DR20 among the numerically predominant strains was related to the presence or absence of a stable indigenous population of lactobacilli during the control period. Strain DR20 did not persist at levels of >102 cells per g in the feces of most of the subjects after consumption of the product ceased; the only exception was one subject in which this strain was detected for 2 months during the posttest period. We concluded that consumption of the DR20-containing milk product transiently altered the Lactobacillus and enterococcal contents of the feces of the majority of consumers without markedly affecting biochemical or other bacteriological factors.

scholarly journals Diversity and Seasonal Variability of β-Proteobacteria in Biofilms of Polluted Rivers: Analysis by Temperature Gradient Gel Electrophoresis and Cloning

2003 ◽  
Vol 69 (8) ◽  
pp. 4463-4473 ◽  
Author(s):  
I. H. M. Brümmer ◽  
A. Felske ◽  
I. Wagner-Döbler
Keyword(s):  
Temperature Gradient ◽  
16S Rrna ◽  
Seasonal Variability ◽  
Gel Electrophoresis ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
High Temporal Resolution ◽  
Gradient Gel Electrophoresis ◽  
Temperature Gradient Gel Electrophoresis ◽  
River Biofilm

ABSTRACT The β-subgroup of the Proteobacteria has been shown to be important in aquatic habitats and was investigated in depth here by molecular 16S rRNA techniques in biofilms of the Elbe River and its polluted tributary, the Spittelwasser River. The bacterial 16S rRNA genes were cloned from each site, screened for β-proteobacterial clones and sequenced. River biofilm clones from both rivers grouped into 9 clusters (RBFs). RBFs 1, 2, and 3 fell into the recently described βI cluster of cosmopolitan freshwater bacteria, where they represented new species related to Rhodoferax, Aquaspirillum, and Hydrogenophaga. RBFs 4 to 7 affiliated with Aquabacterium commune, Ideonella dechloratans, and Sphaerotilus natans, respectively. The two remaining RBFs were uncultivated clusters, one of them being distantly related to Gallionella ferruginea. Seasonal changes in the relative intensity of the β-proteobacterial 16S rRNA genes of biofilms harvested monthly for 1 year were determined by specific amplification and separation by temperature gradient gel electrophoresis (TGGE). Bands were identified by comparison of clones to community fingerprints by TGGE. Eight of 13 identified bands were shared by both habitats but showed different relative abundance and seasonal variability in the two rivers, probably caused by differences in temperature and pollutants. The data indicate new not-yet-cultivated clusters of river biofilm organisms, some of them probably distributed globally. They confirm the importance of certain known freshwater genera in river biofilms. The high phylogenetic resolution obtained by clone library analysis combined with the high temporal resolution obtained by TGGE suggest that the observed microdiversity in the river biofilm clone libraries might be caused by phylogenetically closely related microbial populations which are adapted to ecological parameters.

Genetic Diversity of the Biofilm CoveringMontacuta ferruginosa (Mollusca, Bivalvia) as Evaluated by Denaturing Gradient Gel Electrophoresis Analysis and Cloning of PCR-Amplified Gene Fragments Coding for 16S rRNA†

1998 ◽  
Vol 64 (9) ◽  
pp. 3464-3472 ◽  
Author(s):  
David C. Gillan ◽  
Arjen G. C. L. Speksnijder ◽  
Gabriel Zwart ◽  
Chantal De Ridder
Keyword(s):  
Genetic Diversity ◽  
16S Rrna ◽  
Dna Extraction ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Gradient Gel Electrophoresis ◽  
Biofilm Bacteria ◽  
Sequence Types

The shell of the bivalve Montacuta ferruginosa, a symbiont living in the burrow of an echinoid, is covered with a rust-colored biofilm. This biofilm includes different morphotypes of bacteria that are encrusted with a mineral rich in ferric ion and phosphate. The aim of this research was to determine the genetic diversity and phylogenetic affiliation of the biofilm bacteria. Also, the possible roles of the microorganisms in the processes of mineral deposition within the biofilm, as well as their impact on the biology of the bivalve, were assessed by phenotypic inference. The genetic diversity was determined by denaturing gradient gel electrophoresis (DGGE) analysis of short (193-bp) 16S ribosomal DNA PCR products obtained with primers specific for the domain Bacteria. This analysis revealed a diverse consortium; 11 to 25 sequence types were detected depending on the method of DNA extraction used. Individual biofilms analyzed by using the same DNA extraction protocol did not produce identical DGGE profiles. However, different biofilms shared common bands, suggesting that similar bacteria can be found in different biofilms. The phylogenetic affiliations of the sequence types were determined by cloning and sequencing the 16S rRNA genes. Close relatives of the genera Pseudoalteromonas,Colwellia, and Oceanospirillum (members of the γ-Proteobacteria lineage), as well as Flexibacter maritimus (a member of theCytophaga-Flavobacter-Bacteroides lineage), were found in the biofilms. We inferred from the results that some of the biofilm bacteria could play a role in the mineral formation processes.

Analyses of microbial activity in biomass-recycle reactors using denaturing gradient gel electrophoresis of 16S rDNA and 16S rRNA PCR products

2002 ◽  
Vol 48 (4) ◽  
pp. 333-341 ◽  
Author(s):  
Christine A Morgan ◽  
Andre Hudson ◽  
Allan Konopka ◽  
Cindy H Nakatsu
Keyword(s):  
Community Structure ◽  
16S Rrna ◽  
16S Rdna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Community Response ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Specific Content ◽  
Gradient Gel Electrophoresis

The relationship between mixed microbial community structure and physiology when grown under substrate-limited conditions was investigated using continuous-flow bioreactors with 100% biomass recycle. Community structure was analyzed by denaturing gradient gel electrophoresis (DGGE) of the PCR and RT-PCR amplified V3 region of 16S rDNA and 16S rRNA templates, respectively. Comparisons were made of communities exposed to different types of transient conditions (e.g., long- and short-term starvation, increasing nutrients). With progressively more stringent substrate limitation over time, the specific content of community RNA declined by more than 10-fold and closely followed the decline in specific growth rate. In contrast, the DNA content was variable (up to 3-fold differences) and did not follow the same trend. Cluster analysis of the presence or absence of individual bands indicated that the fingerprints generated by the two templates were different, and community response was first observed in the rRNA fraction. However, both the rDNA and rRNA fingerprints provided a picture of temporal population dynamics. Dice similarity coefficients gave a quantitative measure of the differences and changes between the communities. In comparison, standard cultivation techniques yielded only a quarter of the phylotypes detected by DGGE, but included the most dominant population based on rRNA. Nucleotide-sequence analyses of the almost complete 16S rRNA genes of these isolates place them in the same group of organisms that is typically cultivated from environmental samples: α, β, and γ Proteobacteria and the high GC and the low GC Gram-positive divisions.Key words: 16S rRNA, DGGE, community analysis, biomass-recycle reactor.

scholarly journals Development and Application of a Selective PCR-Denaturing Gradient Gel Electrophoresis Approach To Detect a Recently Cultivated Bacillus Group Predominant in Soil

2004 ◽  
Vol 70 (10) ◽  
pp. 5801-5809 ◽  
Author(s):  
Vesela A. Tzeneva ◽  
Youguo Li ◽  
Andreas D. M. Felske ◽  
Willem M. de Vos ◽  
Antoon D. L. Akkermans ◽  
...  
Keyword(s):  
16S Rrna ◽  
The Netherlands ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Physiological State ◽  
Soil Samples ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Gradient Gel Electrophoresis

ABSTRACT The worldwide presence of a hitherto-nondescribed group of predominant soil microorganisms related to Bacillus benzoevorans was analyzed after development of two sets of selective primers targeting 16S rRNA genes in combination with denaturing gradient gel electrophoresis (DGGE). The high abundance and cultivability of at least some of these microorganisms makes them an appropriate subject for studies on their biogeographical dissemination and diversity. Since cultivability can vary significantly with the physiological state and even between closely related strains, we developed a culture-independent 16S rRNA gene-targeted DGGE fingerprinting protocol for the detection of these bacteria from soil samples. The composition of the B. benzoevorans relatives in the soil samples from The Netherlands, Bulgaria, Russia, Pakistan, and Portugal showed remarkable differences between the different countries. Differences in the DGGE profiles of these communities in archived soil samples from the Dutch Wieringermeer polder were observed over time during which a shift from anaerobic to aerobic and from saline to freshwater conditions occurred. To complement the molecular methods, we additionally cultivated B. benzoevorans-related strains from all of the soil samples. The highest number of B. benzoevorans relatives was found in the soils from the northern part of The Netherlands. The present study contributes to our knowledge of the diversity and abundance of this interesting group of microbes in soils throughout the world.

scholarly journals Evaluations of Different Hypervariable Regions of Archaeal 16S rRNA Genes in Profiling of Methanogens by Archaea-Specific PCR and Denaturing Gradient Gel Electrophoresis

2007 ◽  
Vol 74 (3) ◽  
pp. 889-893 ◽  
Author(s):  
Zhongtang Yu ◽  
Rubén García-González ◽  
Floyd L. Schanbacher ◽  
Mark Morrison
Keyword(s):  
16S Rrna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Specific Pcr ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
V Region

ABSTRACT Different hypervariable (V) regions of the archaeal 16S rRNA gene (rrs) were compared systematically to establish a preferred V region(s) for use in Archaea-specific PCR-denaturing gradient gel electrophoresis (DGGE). The PCR products of the V3 region produced the most informative DGGE profiles and permitted identification of common methanogens from rumen samples from sheep. This study also showed that different methanogens might be detected when different V regions are targeted by PCR-DGGE. Dietary fat appeared to transiently stimulate Methanosphaera stadtmanae but inhibit Methanobrevibacter sp. strain AbM4 in rumen samples.

scholarly journals Colonization and Development of the Fecal Microflora of South China Tiger Cubs (Panthera tigris amoyensis) by Sequencing of the 16S rRNA Gene

2021 ◽  
pp. 1-12
Author(s):  
Yanfa Sun ◽  
Jie Yao ◽  
Min Zhang ◽  
Tengteng Chen ◽  
Weihua Xu ◽  
...  
Keyword(s):  
16S Rrna ◽  
South China ◽  
Fecal Microbiota ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Panthera Tigris ◽  
Gut Health ◽  
Fecal Samples ◽  
Fecal Microflora

Postnatal colonization and development of the gut microbiota is linked to health and growth. A comprehensive understanding of the postnatal compositional changes and development of the microbial community is helpful to understand the gut health and improve the survival rate of South China tiger cubs (<i>Panthera tigris amoyensis</i>). Fecal samples from three tiger cubs were collected on the day of birth in 2018 (June 17–21 [G0], July 18 [G1], July 31 [G2], and August 7 [G3]). The 16S rRNA genes of the fecal microflora were sequenced. Results showed that 38 phyla, 58 classes, 134 orders, 272 families, and 636 genera of bacteria from 3,059 operational taxonomic units were identified from 12 fecal samples. The diversity and abundance of species of group G0 were significantly higher (<i>p</i> &#x3c; 0.05 or 0.01) than those of groups G2 and G3. The predominant phylum was Proteobacteria in groups G0 and G1 (38.85% and 48%, respectively) and Firmicutes in groups G2 and G3 (71.42% and 75.29%, respectively). At the phylum level, the abundance of Deinococcus-Thermus was significantly decreased in groups G1, G2, and G3 as compared to group G0 (<i>p</i> &#x3c; 0.05), while that of Firmicutes was significantly increased in groups G2 and G3 (<i>p</i> &#x3c; 0.05). At the genus level, the abundance of <i>Faecalibacterium</i>, <i>Ralstonia</i>, and unidentified <i>Rickettsiales</i> was significantly decreased in groups G1, G2, and G3 as compared with group G0 (<i>p</i> &#x3c; 0.05), while that of <i>Pseudomonas</i> was significantly decreased in groups G2 and G3 (<i>p</i> &#x3c; 0.05). The composition and structure of fecal microbiota of South China tiger cubs changed after birth.

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