scholarly journals Genomic and physiological characterization of Novosphingobium terrae sp. nov., an alphaproteobacterium isolated from Cerrado soil containing a megasized chromid

2021 ◽  
Author(s):  
Aline Belmok ◽  
Felipe Marques Almeida ◽  
Rodrigo Theodoro Rocha ◽  
Carla Simone Vizzotto ◽  
Marcos Rogério Tótola ◽  
...  
Keyword(s):  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Rrna Gene ◽  
Whole Genome ◽  
High Sequence Identity ◽  
Distinctive Features ◽  
Full Characterization ◽  
Physiological Characterization ◽  
Spherical Structures

A novel bacterial strain, designated GeG2T, was isolated from soils of native Cerrado, a highly biodiverse savanna-like Brazilian biome. 16S rRNA gene sequence analysis of strain GeG2T revealed high sequence identity (100%) to the alphaproteobacterium Novosphingobium rosa, however, comparisons with N. rosa DSM7285T showed several distinctive features, prompting a full characterization of the new strain in terms of growth, morphology, biochemistry and, ultimately, its genome. GeG2T cells were Gram-stain negative bacilli, facultatively anaerobic, motile, positive for catalase and oxidase activities and for starch hydrolysis. Strain GeG2T presented planktonic-sessile dimorphism and cell aggregates surrounded by extracellular matrix and nanometric spherical structures were observed in liquid cultures, suggesting the production of exopolysaccharides (EPS) and outer membrane vesicles (OMVs). Whole genome assembly revealed four circular replicons: a 4.1 Mb chromosome, a 2.7 Mb extrachromosomal megareplicon and two plasmids (212.7 and 68.6 kb). The megareplicon contains few core genes and plasmid-type replication/maintenance systems, consistent with its classification as a chromid. Genome annotation shows a vast repertoire of carbohydrate active enzymes and genes involved in the degradation of aromatic compounds, highlighting the biotechnological potential of the new isolate obtained from Cerrado soils, especially regarding EPS production and biodegradation of recalcitrant compounds. Chemotaxonomic features, including polar lipid and fatty acid profiles, as well as physiological, molecular and whole genome comparisons showed significant differences between strain GeG2T and a N. rosa, clearly indicating that it represents a novel species, for which the name Novosphingobium terrae is proposed. The type strain is GeG2T (=CBMAI 2313T =CBAS 753T ).

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

Characterization of outer membrane vesicles of Acetobacter pasteurianus NBRC3283

2018 ◽  
Vol 125 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Masahito Hashimoto ◽  
Taichi Matsumoto ◽  
Miwa Tamura-Nakano ◽  
Mami Ozono ◽  
Shuhei Hashiguchi ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Acetobacter Pasteurianus

scholarly journals Structural Elucidation of a Novel Lipooligosaccharide from the Cold-Adapted Bacterium OMVs Producer Shewanella sp. HM13

Marine Drugs ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 34 ◽  
Author(s):  
Angela Casillo ◽  
Rossella Di Guida ◽  
Sara Carillo ◽  
Chen Chen ◽  
Kouhei Kamasaka ◽  
...  
Keyword(s):  
Membrane Vesicles ◽  
13C Nmr Spectroscopy ◽  
Alkaline Treatment ◽  
Outer Membrane Vesicles ◽  
1H And 13C Nmr ◽  
Cold Adapted ◽  
Cargo Protein ◽  
Shewanella Species ◽  
Ulosonic Acid

Shewanella sp. HM13 is a cold-adapted Gram-negative bacterium isolated from the intestine of a horse mackerel. It produces a large amount of outer membrane vesicles (OMVs), which are particles released in the medium where the bacterium is cultured. This strain biosynthesizes a single major cargo protein in the OMVs, a fact that makes Shewanella sp. HM13 a good candidate for the production of extracellular recombinant proteins. Therefore, the structural characterization of the components of the vesicles, such as lipopolysaccharides, takes on a fundamental role for understanding the mechanism of biogenesis of the OMVs and their applications. The aim of this study was to investigate the structure of the oligosaccharide (OS) isolated from Shewanella sp. HM13 cells as the first step for a comparison with that from the vesicles. The lipooligosaccharide (LOS) was isolated from dry cells, purified, and hydrolyzed by alkaline treatment. The obtained OS was analyzed completely, and the composition of fatty acids was obtained by chemical methods. In particular, the OS was investigated in detail by 1H and 13C NMR spectroscopy and MALDI-TOF mass spectrometry. The oligosaccharide was characterized by the presence of a residue of 8-amino-3,8-dideoxy-manno-oct-2-ulosonic acid (Kdo8N) and of a d,d-heptose, with both residues being identified in other oligosaccharides from Shewanella species.

scholarly journals Identification and characterization of the α-CA in the outer membrane vesicles produced by Helicobacter pylori

2019 ◽  
Vol 34 (1) ◽  
pp. 189-195 ◽  
Author(s):  
Maurizio Ronci ◽  
Sonia Del Prete ◽  
Valentina Puca ◽  
Simone Carradori ◽  
Vincenzo Carginale ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Identification And Characterization

scholarly journals Characterization of Phascolarctobacterium succinatutens sp. nov., an Asaccharolytic, Succinate-Utilizing Bacterium Isolated from Human Feces

2011 ◽  
Vol 78 (2) ◽  
pp. 511-518 ◽  
Author(s):  
Yohei Watanabe ◽  
Fumiko Nagai ◽  
Masami Morotomi
Keyword(s):  
Bacterial Species ◽  
Short Chain Fatty Acids ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Gi Tract ◽  
Bacterial Strains ◽  
High Sequence Identity ◽  
Healthy Human ◽  
Content Type

ABSTRACTIsolation, cultivation, and characterization of the intestinal microorganisms are important for understanding the comprehensive physiology of the human gastrointestinal (GI) tract microbiota. Here, we isolated two novel bacterial strains, YIT 12067Tand YIT 12068, from the feces of healthy human adults. Phylogenetic analysis indicated that they belonged to the same species and were most closely related toPhascolarctobacterium faeciumACM 3679T, with 91.4% to 91.5% 16S rRNA gene sequence similarities, respectively. Substrate availability tests revealed that the isolates used only succinate; they did not ferment any other short-chain fatty acids or carbohydrates tested. When these strains were cocultured with the xylan-utilizing and succinate-producing bacteriumParaprevotella xylaniphilaYIT 11841T, in medium supplemented with xylan but not succinate, their cell numbers became 2 to 3 orders of magnitude higher than those of the monoculture; succinate became undetectable, and propionate was formed. Database analysis revealed that over 200 uncultured bacterial clones from the feces of humans and other mammals showed high sequence identity (>98.7%) to YIT 12067T. Real-time PCR analysis also revealed that YIT 12067T-like bacteria were present in 21% of human fecal samples, at an average level of 3.34 × 108cells/g feces. These results indicate that YIT 12067T-like bacteria are distributed broadly in the GI tract as subdominant members that may adapt to the intestinal environment by specializing to utilize the succinate generated by other bacterial species. The phylogenetic and physiological properties of YIT 12067Tand YIT 12068 suggest that these strains represent a novel species, which we have designatedPhascolarctobacterium succinatutenssp. nov.

Proteomic and functional characterization of the outer membrane vesicles from the gastric pathogen Helicobacter pylori

2009 ◽  
Vol 3 (7) ◽  
pp. 785-796 ◽  
Author(s):  
Erica Mullaney ◽  
Paul A. Brown ◽  
Sinead M. Smith ◽  
Catherine H. Botting ◽  
Yoshio Y. Yamaoka ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Functional Characterization ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Gastric Pathogen

Characterization of the key antigenic components of pertussis vaccine based on outer membrane vesicles

Vaccine ◽  
2014 ◽  
Vol 32 (46) ◽  
pp. 6084-6090 ◽  
Author(s):  
Maximiliano Ormazábal ◽  
Erika Bartel ◽  
María Emilia Gaillard ◽  
Daniela Bottero ◽  
Agustina Errea ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Pertussis Vaccine ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles
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