scholarly journals Characterization of attached bacterial populations in deep granitic groundwater from the Stripa research mine by 16S rRNA gene sequencing and scanning electron microscopy

Microbiology ◽  
1994 ◽  
Vol 140 (7) ◽  
pp. 1575-1583 ◽  
Author(s):  
S. EKENDAHL ◽  
J. ARLINGER ◽  
F. STAHL ◽  
K. PEDERSEN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Bacterial Populations ◽  
Rrna Gene Sequencing ◽  
Granitic Groundwater ◽  
Scanning Electron

scholarly journals Characterization of the Spoilage Microbiota of Hake Fillets Packaged Under a Modified Atmosphere (MAP) Rich in CO2 (50% CO2/50% N2) and Stored at Different Temperatures

Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 489 ◽  
Author(s):  
Adriana Antunes-Rohling ◽  
Silvia Calero ◽  
Nabil Halaihel ◽  
Pedro Marquina ◽  
Javier Raso ◽  
...  
Keyword(s):  
Storage Temperature ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Modified Atmosphere ◽  
Modified Atmospheres ◽  
Different Temperatures ◽  
Rrna Gene Sequencing ◽  
Storage Temperatures

The aim of this study was to characterize the spoilage microbiota of hake fillets stored under modified atmospheres (MAP) (50% CO2/50% N2) at different temperatures using high-throughput 16S rRNA gene sequencing and to compare the results with those obtained using traditional microbiology techniques. The results obtained indicate that, as expected, higher storage temperatures lead to shorter shelf-lives (the time of sensory rejection by panelists). Thus, the shelf-life decreased from six days to two days for Batch A when the storage temperature increased from 1 to 7 °C, and from five to two days—when the same increase in storage temperature was compared—for Batch B. In all cases, the trimethylamine (TMA) levels measured at the time of sensory rejection of hake fillets exceeded the recommended threshold of 5 mg/100 g. Photobacterium and Psychrobacter were the most abundant genera at the time of spoilage in all but one of the samples analyzed: Thus, Photobacterium represented between 19% and 46%, and Psychrobacter between 27% and 38% of the total microbiota. They were followed by Moritella, Carnobacterium, Shewanella, and Vibrio, whose relative order varied depending on the sample/batch analyzed. These results highlight the relevance of Photobacterium as a spoiler of hake stored in atmospheres rich in CO2. Further research will be required to elucidate if other microorganisms, such as Psychrobacter, Moritella, or Carnobacterium, also contribute to spoilage of hake when stored under MAP.

Biodegradation of benzothiophene sulfones by a filamentous bacterium

1999 ◽  
Vol 45 (5) ◽  
pp. 360-368 ◽  
Author(s):  
David C Bressler ◽  
Brenda K Leskiw ◽  
Phillip M Fedorak
Keyword(s):  
Thiophene Ring ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Filamentous Bacterium ◽  
Hexadecanoic Acid ◽  
Dibenzothiophene Sulfone ◽  
Sulfur Heterocycles ◽  
Rrna Gene Sequencing ◽  
Scanning Electron

Previous studies showed that benzothiophene and 3- and 5-methylbenzothiophenes are oxidized by some bacteria to yield their corresponding sulfones, which were not subsequently degraded. In this study, a filamentous bacterium was isolated, which grew on each of these three sulfones as its sole carbon, sulfur, and energy source. Based on 16S rRNA gene sequencing and scanning electron microscopy, the isolate was found to belong to the genus Pseudonocardia and assigned the strain designation DB1. Benzothiophene sulfone and 3-methylbenzothiophene sulfone were more readily biodegraded than 5-methylbenzothiophene sulfone, and growth on these three compounds resulted in the release of 57, 62, and 28% of the substrate carbon as CO2, respectively. The thiophene ring was also cleaved, and between 44 and 88% of the sulfur from the consumed substrate was found as sulfate and (or) sulfite. Strain DB1 grew on benzoate, dibenzothiophene sulfone, and hexadecanoic acid, but it could not grow on benzofuran, dibenzothiophene, dibenzothiophene sulfoxide, hexadecane, indole, naphthalene, phenol, 2-sulfobenzoic acid, sulfolane, benzothiophene, or 3- or 5-methylbenzothiophenes. In addition, it did not oxidize the latter three compounds to their sulfones.Key words: benzothiophene sulfone, biodegradation, mineralization, sulfur heterocycles, Pseudonocardia.

scholarly journals Optimal protocols for sequence-based characterization of the human vaginal microbiome

2020 ◽  
Author(s):  
Luisa W. Hugerth ◽  
Marcela Pereira ◽  
Yinghua Zha ◽  
Maike Seifert ◽  
Vilde Kaldhusdal ◽  
...  
Keyword(s):  
16S Rrna ◽  
Best Practices ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Vaginal Microbiome ◽  
Wide Range ◽  
Rrna Gene Sequencing ◽  
Good Agreement

AbstractThe vaginal microbiome has been connected to a wide range of health outcomes. This has led to a thriving research environment, but also to the use of conflicting methodologies to study its microbial composition. Here we systematically assess best practices for the sequencing-based characterization of the human vaginal microbiome. As far as 16S rRNA gene sequencing is concerned, the V1-V3 region has the best theoretical properties, but limitations of current sequencing technologies mean that the V3-V4 region performs equally well. Both of these approaches present very good agreement with qPCR quantification of key taxa, provided an appropriate bioinformatic pipeline is used. Shotgun metagenomic sequencing presents an interesting alternative to 16S amplification and sequencing, but it is not without its challenges. We have assessed different tools for the removal of host reads and the taxonomic annotation of metagenomic reads, including a new, easy-to-build and – use, reference database of vaginal taxa. This strategy performed as well as the best performing previously published strategies. Despite the many advantages of shotgun sequencing none of the shotgun approaches assessed here had as good agreement with the qPCR data as 16S rRNA gene sequencing.ImportanceThe vaginal microbiome has been connected to a wide range of health outcomes, from susceptibility to sexually transmitted infections to gynecological cancers and pregnancy outcomes. This has led to a thriving research environment, but also to conflicting available methodologies, including many studies that do not report their molecular biological and bioinformatic methods in sufficient detail for them to be considered reproducible. This can lead to conflicting messages and delay progress from descriptive to intervention studies. By systematically assessing best practices for the characterization of the human vaginal microbiome, this study will enable past studies to be assessed more critically and assist future studies in the selection of appropriate methods for their specific research questions.

scholarly journals Mycobacterium saskatchewanense sp. nov., a novel slowly growing scotochromogenic species from human clinical isolates related to Mycobacterium interjectum and Accuprobe-positive for Mycobacterium avium complex

2004 ◽  
Vol 54 (3) ◽  
pp. 659-667 ◽  
Author(s):  
C. Y. Turenne ◽  
L. Thibert ◽  
K. Williams ◽  
T. V. Burdz ◽  
V. J. Cook ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Novel Species ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Rrna Gene Sequencing ◽  
Established Species ◽  
Rdna Analysis ◽  
Selection Of

A pigmented, slowly growing Mycobacterium avium complex AccuProbe-positive organism was isolated from the sputum and pleural fluid of a 72-year-old female with bronchiectasis. The unusual morphology of the organism prompted further identification by 16S rRNA gene sequencing, revealing a perfect identity with previously uncharacterized strain Mycobacterium sp. MCRO 8 (GenBank accession no. X93034), with the closest established species by 16S rDNA analysis being Mycobacterium interjectum. HPLC of the organism corresponded to previously obtained patterns identified as M. interjectum-like and, upon sequence evaluation of a selection of strains with a similar profile, more were subsequently identified as MCRO 8. A total of 16 strains isolated from human respiratory samples were evaluated in the characterization of this novel species, for which the name Mycobacterium saskatchewanense sp. nov. is proposed. The type strain is strain 00-250T (=ATCC BAA-544T=DSM 44616T=CIP 108114T).

Microbiota characterization of sheep milk and its association with somatic cell count using 16s rRNA gene sequencing

2019 ◽  
Vol 137 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Cristina Esteban‐Blanco ◽  
Beatriz Gutiérrez‐Gil ◽  
Fernando Puente‐Sánchez ◽  
Héctor Marina ◽  
Javier Tamames ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Sheep Milk ◽  
Rrna Gene Sequencing

scholarly journals Pseudoxanthomonas winnipegensis sp. nov., derived from human clinical materials and recovered from cystic fibrosis and other patient types in Canada, and emendation of Pseudoxanthomonas spadix Young et al. 2007

2020 ◽  
Vol 70 (12) ◽  
pp. 6313-6322
Author(s):  
Kathryn A. Bernard ◽  
Alicia Vachon ◽  
Ana Luisa Pacheco ◽  
Tamara Burdz ◽  
Deborah Wiebe ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cystic Fibrosis ◽  
Type Species ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Whole Genome ◽  
Content Type ◽  
Link Type ◽  
Rrna Gene Sequencing

Twelve isolates recovered from 10 cystic fibrosis/other patient types and a variety of clinical sources, were referred to Canada's National Microbiology Laboratory over 7 years. These were assignable to the genus Pseudoxanthomonas but were unidentifiable to species level. Patients included five males and five females from two geographically separated provinces, ranging in age from 2 months to 84 years. In contrast, most Pseudoxanthomonas species described to date have been derived from water, plants or contaminated soils. By 16S rRNA gene sequencing, the patient strains had ≥99.4 % similarity to each other but only 97.73–98.29 % to their closest relatives, Pseudoxanthomonas spadix or Pseudoxanthomonas helianthi . Bacteria were studied by whole genome sequencing using average nucleotide identity by Blastn, digital DNA–DNA hybridization, average amino acid identity, core genome and single nucleotide variant analyses, MALDI-TOF, biochemical and cellular fatty acid analyses, and by antimicrobial susceptibility testing. Bacterial structures were assessed using scanning and transmission electron microscopy. Strains were strict aerobes, yellowish-pigmented, oxidative, non-motile, Gram-stain-negative bacilli and generally unable to reduce nitrate. Strains were susceptible to most of the antibiotics tested; some resistance was observed towards carbapenems, several cephems and uniformly to nitrofurantoin. The single taxon group observed by 16S rRNA gene sequencing was supported by whole genome sequencing; genomes ranged in size from 4.36 to 4.73 Mb and had an average G+C content of 69.12 mol%. Based on this study we propose the name Pseudoxanthomonas winnipegensis sp. nov. for this cluster. Pseudoxanthomonas spadix DSM 18855T, acquired for this study, was found to be non-motile phenotypically and by electron microscopy; we therefore propose the emendation of Pseudoxanthomonas spadix Young et al. 2007 to document that observation.

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