Microbial Ecology

, Volume 51, Issue 4, pp 501–507 | Cite as

Ultrastructural Analysis of the Extracellular Matter Secreted by the Psychrotolerant Bacterium Pseudoalteromonas antarctica NF3

  • Maria Nevot
  • Victor Deroncele
  • Carmen López-Iglesias
  • Nuria Bozal
  • Jesús Guinea
  • Elena Mercade


The psychrotolerant strain Pseudoalteromonas antarctica NF3, a Gram-negative bacterium isolated from muddy soil samples of Antarctica, secretes large amounts of a mucoid exopolymer with a high protein content. It has self-assembly properties and capacity to coat and protect liposomes against surfactants. We examined the ultrastructure of P. antarctica and the extracellular matter it secretes by transmission electron microscopy (TEM) after high-pressure freezing, freeze substitution (HPF-FS), and Epon embedding, and compared this with information obtained by conventional methods. The improvements brought about by HPF-FS to the ultrastructural preservation of the extracellular matter allowed us to establish for the first time, in P. antarctica NF3, the presence of two components: a large amount of cell-derived outer membrane vesicles containing proteins and a capsular polymer around the cells.


Transmission Electron Microscopy Analysis Extracellular Matter Freeze Substitution Exopolymeric Substance Ultrastructural Preservation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We gratefully acknowledge the help received from the Serveis Científico Tècnics de la Universitat de Barcelona, G. Martinez, S. Ruiz, and E. Coll, for TEM support. We also thank Robin Rycroft for editorial assistance. Part of this research was supported by the Agència de Gestió d'Ajuts Universitaris i de Recerca of the Generalitat de Catalunya (grant 2001/SGR/00126). M. Nevot is the recipient of a fellowship from the Fundació Universitària Agustí Pedro Pons.


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Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Maria Nevot
    • 2
  • Victor Deroncele
    • 2
  • Carmen López-Iglesias
    • 1
  • Nuria Bozal
    • 2
  • Jesús Guinea
    • 2
  • Elena Mercade
    • 2
  1. 1.Scientific-Technical Services of the University of BarcelonaBarcelonaSpain
  2. 2.Departament de Microbiologia i Parasitologia Sanitàries, Facultat de FarmàciaUniversitat de BarcelonaBarcelonaSpain

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