Extensive Gene Acquisition in the Extremely Psychrophilic Bacterial Species Psychroflexus torquis and the Link to Sea-Ice Ecosystem Specialism

Shi Feng; Shane M. Powell; Richard Wilson; John P. Bowman

doi:10.1093/gbe/evt209

Extensive Gene Acquisition in the Extremely Psychrophilic Bacterial Species Psychroflexus torquis and the Link to Sea-Ice Ecosystem Specialism

Genome Biology and Evolution ◽

10.1093/gbe/evt209 ◽

2014 ◽

Vol 6 (1) ◽

pp. 133-148 ◽

Cited By ~ 37

Author(s):

Shi Feng ◽

Shane M. Powell ◽

Richard Wilson ◽

John P. Bowman

Keyword(s):

Sea Ice ◽

Bacterial Species ◽

Gene Acquisition

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Risk factors for Klebsiella pneumoniae carbapenemase (KPC) gene acquisition and clinical outcomes across multiple bacterial species

Journal of Hospital Infection ◽

10.1016/j.jhin.2020.01.005 ◽

2020 ◽

Vol 104 (4) ◽

pp. 456-468 ◽

Cited By ~ 5

Author(s):

A.J. Mathers ◽

K. Vegesana ◽

I. German-Mesner ◽

J. Ainsworth ◽

A. Pannone ◽

...

Keyword(s):

Risk Factors ◽

Klebsiella Pneumoniae ◽

Clinical Outcomes ◽

Bacterial Species ◽

Klebsiella Pneumoniae Carbapenemase ◽

Gene Acquisition

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Characteristics of genetically diverse Antarctic sea ice bacteriophages allow adaptation to changing environmental conditions

10.1101/2021.05.28.446129 ◽

2021 ◽

Author(s):

Tatiana A. Demina ◽

Anne-Mari Luhtanen ◽

Simon Roux ◽

Hanna Oksanen

Keyword(s):

Sea Ice ◽

Global Climate ◽

Bacterial Species ◽

Host Recognition ◽

Global Changes ◽

Viral Genomes ◽

Antarctic Sea Ice ◽

Virus Diversity ◽

Wide Range ◽

The Impact

Despite generally appreciated significant roles of microbes in sea ice and polar waters, detailed studies of virus-host systems from such environments have been so far limited by only a few isolates. Here, we investigated infectivity under changing conditions, infection cycles, and genetic diversity of four bacteriophages isolated from Antarctic sea ice: PANV1, PANV2, OANV1, and OANV2, infecting common sea ice bacterial species Paraglaciecola or Octadecabacter. Although the phages are marine and cold-active, replicating at 0-5 C, they all survived temporal incubations at 30 C or above and remained infectious without any salts or supplemented only with magnesium, suggesting a robust virion assembly maintaining integrity under a wide range of conditions. Host recognition in the cold proved to be effective, and the release of progeny viruses occurred as a result of cell lysis or host growth retardation. The analysis of viral genomes showed that nearly half of the gene products of each virus are unique, highlighting that sea ice harbors unexplored virus diversity. Based on predicted genes typical for tailed dsDNA phages, we suggest placing the four studied viruses in the class Caudoviricetes. Searching against viral sequences from metagenomic assemblies revealed that related viruses are not restricted to Antarctica, but also found in distant marine environments, indicating possible virus movement between biotopes. Importance. Very little is known about sea ice microbes despite the significant role of sea ice in the global oceans as well as microbial input into biogeochemical cycling. The impact of possible climatic changes on Antarctic sea ice microbial communities is also poorly understood. Studies on the sea ice viruses have been typically limited to -omics-based approaches and microscopic examinations of sea ice samples. Up to date, only four cultivable viruses have been isolated from Antarctic sea ice. Our study of these unique isolates advances the understanding of the diversity of viruses in sea ice environments, their interactions with host microbes, adaptation potential in the realm of global climate change, and possible links to other biomes. Such information contributes to more accurate future predictions on microbial feedback loops as the response to global changes.

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Structural analysis of the photosynthetic membrane from Ectothiorhodospira halochloris

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007727x ◽

1983 ◽

Vol 41 ◽

pp. 740-741

Author(s):

H. Engelhardt ◽

R. Guckenberger ◽

W. Baumeister

Keyword(s):

Lattice Structure ◽

Bacterial Species ◽

Hexagonal Lattice ◽

Reaction Centre ◽

Photosynthetic Membrane ◽

Rhodopseudomonas Viridis ◽

Photosynthetic Membranes ◽

Ectothiorhodospira Halochloris ◽

Main Components

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).

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