scholarly journals Biodegradation of Endocrine Disruptors in Solid-Liquid Two-Phase Partitioning Systems by Enrichment Cultures

2013 ◽  
Vol 79 (15) ◽  
pp. 4701-4711 ◽  
Author(s):  
Richard Villemur ◽  
Silvia Cristina Cunha dos Santos ◽  
Julianne Ouellette ◽  
Pierre Juteau ◽  
François Lépine ◽  
...  
Keyword(s):  
Endocrine Disruptors ◽  
Urban Areas ◽  
Enrichment Culture ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Two Phase ◽  
Content Type ◽  
Phase Partitioning ◽  
Enrichment Cultures ◽  
Solid Liquid

ABSTRACTNaturally occurring and synthetic estrogens and other molecules from industrial sources strongly contribute to the endocrine disruption of urban wastewater. Because of the presence of these molecules in low but effective concentrations in wastewaters, these endocrine disruptors (EDs) are only partially removed after most wastewater treatments, reflecting the presence of these molecules in rivers in urban areas. The development of a two-phase partitioning bioreactor (TPPB) might be an effective strategy for the removal of EDs from wastewater plant effluents. Here, we describe the establishment of three ED-degrading microbial enrichment cultures adapted to a solid-liquid two-phase partitioning system using Hytrel as the immiscible water phase and loaded with estrone, estradiol, estriol, ethynylestradiol, nonylphenol, and bisphenol A. All molecules except ethynylestradiol were degraded in the enrichment cultures. The bacterial composition of the three enrichment cultures was determined using 16S rRNA gene sequencing and showed sequences affiliated with bacteria associated with the degradation of these compounds, such asSphingomonadales. OneRhodococcusisolate capable of degrading estrone, estradiol, and estriol was isolated from one enrichment culture. These results highlight the great potential for the development of TPPB for the degradation of highly diluted EDs in water effluents.

High absorption of endocrine disruptors by Hytrel: towards the development of a two-phase partitioning bioreactor

2012 ◽  
Vol 88 (1) ◽  
pp. 119-125 ◽  
Author(s):  
Julianne Ouellette ◽  
Silvia Cristina Cunha dos Santos ◽  
François Lépine ◽  
Pierre Juteau ◽  
Eric Déziel ◽  
...  
Keyword(s):  
Endocrine Disruptors ◽  
Two Phase ◽  
Phase Partitioning ◽  
Partitioning Bioreactor ◽  
High Absorption ◽  
Two Phase Partitioning Bioreactor

scholarly journals Abrupt Temporal Fluctuations in the Chicken Fecal Microbiota Are Explained by Its Gastrointestinal Origin

2012 ◽  
Vol 78 (8) ◽  
pp. 2941-2948 ◽  
Author(s):  
M. Sekelja ◽  
I. Rud ◽  
S. H. Knutsen ◽  
V. Denstadli ◽  
B. Westereng ◽  
...  
Keyword(s):  
Barrier Function ◽  
16S Rrna Gene Sequencing ◽  
Fecal Microbiota ◽  
Pathogen Transmission ◽  
Rrna Gene ◽  
Multivariate Statistical ◽  
Content Type ◽  
Factors Affecting ◽  
Temporal Fluctuations ◽  
Gastric Barrier

ABSTRACTOne of the main challenges in understanding the composition of fecal microbiota is that it can consist of microbial mixtures originating from different gastrointestinal (GI) segments. Here, we addressed this challenge for broiler chicken feces using a direct 16S rRNA gene-sequencing approach combined with multivariate statistical analyses. Broiler feces were chosen because of easy sampling and the importance for pathogen transmission to the human food chain. Feces were sampled daily for 16 days from chickens with and without a feed structure-induced stimulation of the gastric barrier function. Overall, we found four dominant microbial phylogroups in the feces. Two of the phylogroups were related to clostridia, one to lactobacilli, and one toEscherichia/Shigella. The relative composition of these phylogroups showed apparent stochastic temporal fluctuations in feces. Analyses of dissected chickens at the end of the experiment, however, showed that the two clostridial phylogroups were correlated to the microbiota in the cecum/colon and the small intestine, while the upper gut (crop and gizzard) microbiota was correlated to the lactobacillus phylogroup. In addition, chickens with a stimulated gizzard also showed less of the proximate GI dominating bacterial group in the feces, supporting the importance of the gastric barrier function. In conclusion, our results suggest that GI origin is a main determinant for the chicken fecal microbiota composition. This knowledge will be important for future understanding of factors affecting shedding of both harmful and beneficial gastrointestinal bacteria through feces.

scholarly journals Citroniella saccharovorans gen. nov. sp. nov., a member of the family Peptoniphilaceae isolated from a human fecal sample from a coastal traditional community member

2019 ◽  
Vol 69 (4) ◽  
pp. 1142-1148 ◽  
Author(s):  
Nisha B. Patel ◽  
Alexandra J. Obregón-Tito ◽  
Raul Y. Tito ◽  
Omar Trujillo-Villaroel ◽  
Luis Marin-Reyes ◽  
...  
Keyword(s):  
Fecal Sample ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
The Novel ◽  
Content Type ◽  
Link Type ◽  
Novel Bacterium ◽  
The Family ◽  
Diamino Acid ◽  
Rrna Gene Sequencing

A novel Gram-stain-positive, non-motile, non-spore-forming coccus-shaped obligately anaerobic bacterium was recovered from a fecal sample obtained from an individual from a traditional community located on the southern coast of Peru. The results of analysis based on 16S rRNA gene sequencing indicated the novel bacterium to be phylogenetically distinct from other genera of members of the Peptoniphilaceae family, sharing a loose affinity with the genera Ezakiella , Finegoldia , Gallicola and Parvimonas . The major cellular fatty acids of the novel isolate were determined to be C16:0, C17:1ω8c, and C18:1ω9c. The DNA G+C content was 29.9 mol%. End products of metabolism from peptone yeast glucose broth (PYG) were determined to be acetate and methyl succinate. The diagnostic diamino acid present in the cell wall was lysine. On the basis of the phenotypic, chemotaxonomic and phylogenetic results the organism is a member of a novel genus belonging to the family Peptoniphilaceae for which the name Citroniella saccharovorans gen nov. sp. nov., is proposed. The type strain is M6.X9T (DSM 29873T=CCUG 66799T).

scholarly journals Tsukamurella pulmonis conjunctivitis in patients with an underlying nasolacrimal duct obstruction – report of two cases

2020 ◽  
Author(s):  
Peter Kechker ◽  
Yigal Senderovich ◽  
Shifra Ken-Dror ◽  
Sivan Laviad-Shitrit ◽  
Malka Halpern
Keyword(s):  
Type Species ◽  
Previous History ◽  
16S Rrna Gene Sequencing ◽  
Nasolacrimal Duct ◽  
Nasolacrimal Duct Obstruction ◽  
Rrna Gene ◽  
Eye Drops ◽  
Content Type ◽  
Duct Obstruction ◽  
Link Type

Tsukamurella pulmonis ( Actinobacteria ), a Gram-positive, obligate aerobic and weakly or variably acid-fast bacterium, is an opportunistic pathogen. Here we report two cases of conjunctivitis caused by T. pulmonis . Both patients had a previous history of nasolacrimal duct obstruction (NLDO). Isolation of T. pulmonis was performed on chocolate, tryptic soy blood and Columbia nalidixic agars. After 24 h of incubation, odourless, white-greyish, membrane-like colonies were observed. The VITEK-2 bacterial identifier system failed to identify the species, while Vitek-MS matrix-assisted laser desorption ionization time-of-flight technology, successfully identified the isolate from case 2 but not from case 1. Final identification was verified using 16S rRNA gene sequencing. An antibiogram was performed and according to the results cefazoline in addition to vancomycin eye drops for 5 days, were suggested as a treatment in case 1. In case 2 the infection was ended without treatment. This is the first report of Tsukamurella as a pathogen that causes conjunctivitis in patients with NLDO.

scholarly journals Impact of Oral Fidaxomicin Administration on the Intestinal Microbiota and Susceptibility to Clostridium difficile Colonization in Mice

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
N. J. Ajami ◽  
J. L. Cope ◽  
M. C. Wong ◽  
J. F. Petrosino ◽  
L. Chesnel
Keyword(s):  
Clostridium Difficile ◽  
Gut Microbiota ◽  
16S Rrna Gene Sequencing ◽  
Taxonomic Structure ◽  
Rrna Gene ◽  
Colonization Resistance ◽  
Content Type ◽  
Rrna Gene Sequencing ◽  
Hospital Acquired ◽  
Predetermined Time

ABSTRACT Clostridium difficile infection (CDI), a common cause of hospital-acquired infections, typically occurs after disruption of the normal gut microbiome by broad-spectrum antibiotics. Fidaxomicin is a narrow-spectrum antibiotic that demonstrates a reduced impact on the normal gut microbiota and is approved for the treatment of CDI. To further explore the benefits of this property, we used a murine model to examine the effects of fidaxomicin versus vancomycin on gut microbiota and susceptibility to C. difficile colonization while tracking microbiota recovery over time. Mice were exposed to fidaxomicin or vancomycin by oral gavage for 3 days and subsequently challenged with C. difficile spores at predetermined time points up to 21 days postexposure to antibiotics. Fecal samples were subsequently collected for analysis. Twenty-four hours postchallenge, mice were euthanized and the colon contents harvested. The microbiota was characterized using 16S rRNA gene sequencing. All fidaxomicin-exposed mice (except for one at day 8) were resistant to C. difficile colonization. However, 9 of 15 vancomycin-exposed mice were susceptible to C. difficile colonization until day 12. All vancomycin-exposed mice recovered colonization resistance by day 16. Bacterial diversity was similar prior to antibiotic exposure in both arms and decreased substantially after exposure. A shift in taxonomic structure and composition occurred after both exposures; however, the shift was greater in vancomycin-exposed than in fidaxomicin-exposed mice. In summary, compared with vancomycin, fidaxomicin exposure had less impact on microbiota composition, promoted faster microbial recovery, and had less impact on the loss of C. difficile colonization resistance.

Solid–liquid two-phase flow and erosion calculation of butterfly valves at small opening based on DEM method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Benliang Xu ◽  
Zuchao Zhu ◽  
Zhe Lin ◽  
Dongrui Wang
Keyword(s):  
Peer Review ◽  
Two Phase Flow ◽  
Solid Particles ◽  
Phase Flow ◽  
Butterfly Valve ◽  
Two Phase ◽  
Content Type ◽  
Small Opening ◽  
Solid Liquid ◽  
The Impact

Purpose The study aims to decrease the effect of solid particles on a butterfly valve, which will cause seal failure and leakage, providing a reference for anti-wear design. Design/methodology/approach In this paper, computational fluid dynamics discrete element method (CFD-DEM) simulation was conducted to study the solid–liquid two-phase flow characteristics and erosion characteristics of a butterfly valve with a different opening. Findings Abrasion at 10% opening is affected by high-speed jets in upper and lower parts of the pipeline, where the erosion is intense. The impact of the jet on the upper part of 20% opening begins to weaken. With the top backflow vortex disappearing, the effect of lower jet is enhanced. Meanwhile, the bottom backflow vortex phenomenon is obvious, and the abrasion position moves downward. At 30% opening, the velocity is further weakened, and the circulation effect of lower flow channel is more obvious than that of the upper one. Originality/value It is the first time to use DEM to investigate the two-phase flow and erosion characteristics at a small opening of a butterfly valve, considering the effect of inter-particle collision. Therefore, this study carries on the thorough analysis and discussion. At the same opening degree, with increasing of the particle size, the abrasion of valve frontal surface increases when the size is less than 150 µm and decreases when it is greater than 150 µm. For the valve backflow surface, this boundary value becomes 200 µm. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0264/

scholarly journals Transition of Bacterial Diversity and Composition in Tongue Microbiota during the First Two Years of Life

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Shinya Kageyama ◽  
Mikari Asakawa ◽  
Toru Takeshita ◽  
Yukari Ihara ◽  
Shunsuke Kanno ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Bacterial Diversity ◽  
Bacterial Species ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Oral Microbiota ◽  
Bacterial Composition ◽  
Content Type ◽  
Operational Taxonomic Units ◽  
Rrna Gene Sequencing

ABSTRACTNewborns are constantly exposed to various microbes from birth; hence, diverse commensal bacteria colonize the oral cavity. However, how or when these bacteria construct a complex and stable ecosystem remains unclear. This prospective cohort study examined the temporal changes in bacterial diversity and composition in tongue microbiota during infancy. We longitudinally collected a total of 464 tongue swab samples from 8 infants (age of <6 months at baseline) for approximately 2 years. We also collected samples from 32 children (aged 0 to 2 years) and 73 adults (aged 20 to 29 years) cross-sectionally as control groups. Bacterial diversities and compositions were determined by 16S rRNA gene sequencing. The tongue bacterial diversity in infancy, measured as the number of observed operational taxonomic units (OTUs), rapidly increased and nearly reached the same level as that in adults by around 80 weeks. The overall tongue bacterial composition in the transitional phase, 80 to 120 weeks, was more similar to that of adults than to that of the early exponential phase (EEP), 10 to 29 weeks, according to analysis of similarities. Dominant OTUs in the EEP corresponding toStreptococcus perorisandStreptococcus lactariusexponentially decreased immediately after EEP, around 30 to 49 weeks, whereas several OTUs corresponding toGranulicatella adiacens,Actinomyces odontolyticus, andFusobacterium periodonticumreciprocally increased during the same period. These results suggest that a drastic compositional shift of tongue microbiota occurs before the age of 1 year, and then bacterial diversity and overall bacterial composition reach levels comparable to those in adults by the age of 2 years.IMPORTANCEEvaluating the development of oral microbiota during infancy is important for understanding the subsequent colonization of bacterial species and the process of formation of mature microbiota in the oral cavity. We examined tongue microbiota longitudinally collected from 8 infants and found that drastic compositional shifts in tongue microbiota occur before the age of 1 year, and then bacterial diversity and overall bacterial composition reach levels comparable to those in adults by the age of 2 years. These results may be helpful for preventing the development of various diseases associated with oral microbiota throughout life.

scholarly journals Whole-Genome Sequencing ofAggregatibacterSpecies Isolated from Human Clinical Specimens and Description ofAggregatibacter kilianiisp. nov.

2018 ◽  
Vol 56 (7) ◽  
Author(s):  
May Murra ◽  
Lisbeth Lützen ◽  
Aynur Barut ◽  
Reinhard Zbinden ◽  
Marianne Lund ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Whole Genome ◽  
Content Type ◽  
Clinical Specimens ◽  
Phylogenetic Cluster ◽  
Invasive Infections ◽  
Rrna Gene Sequencing

ABSTRACTAggregatibacterspecies are commensal bacteria of human mucosal surfaces that are sometimes involved in serious invasive infections. During the investigation of strains cultured from various clinical specimens, we encountered a coherent group of 10 isolates that could not be allocated to any validly named species by phenotype, mass spectrometry, or partial 16S rRNA gene sequencing. Whole-genome sequencing revealed a phylogenetic cluster related to but separate fromAggregatibacter aphrophilus. The meanin silicoDNA hybridization value for strains of the new cluster versusA. aphrophiluswas 56% (range, 53.7 to 58.0%), whereas the average nucleotide identity was 94.4% (range, 93.9 to 94.8%). The new cluster exhibited aggregative properties typical of the genusAggregatibacter. Key phenotypic tests for discrimination of the new cluster from validly namedAggregatibacterspecies are alanine-phenylalanine-proline arylamidase,N-acetylglucosamine, and β-galactosidase. The nameAggregatibacter kilianiiis proposed, with PN_528 (CCUG 70536Tor DSM 105094T) as the type strain.

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