Intracellular inclusions of uncultured magnetotactic bacteria

• Carolina N. Keim; Department of General Microbiology, Institute of Microbiology, Federal University of Rio de Janeiro, Brazil ; and Biomineralization Laboratory, Biomedical Science Institute, Federal University of Rio de Janeiro, Brazil ; Guilhermo Solórzano ^[1] ; Marcos Farina ^[2] ; Ulysses Lins ^[2]
  1. [1] Pontifícia Universidade Católica do Rio de Janeiro

     Pontifícia Universidade Católica do Rio de Janeiro

     Brasil

     
  2. [2] Universidade Federal do Rio de Janeiro

     Universidade Federal do Rio de Janeiro

     Brasil

     
• Localización: International microbiology: official journal of the Spanish Society for Microbiology, ISSN 1139-6709, Vol. 8, Nº. 2, 2005, págs. 111-117
• Idioma: inglés
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• Resumen

  • Magnetotactic bacteria produce magnetic crystals in organelles called magnetosomes. The bacterial cells may also have phosphorus-containing granules, sulfur globules, or polyhydroxyalkanoate inclusions. In the present study, the ultrastructure and elemental composition of intracellular inclusions from uncultured magnetotactic bacteria collected in a marine environment are described. Magnetosomes contained mainly defect-free, single magnetite crystals with prismatic morphologies. Two types of phosphorus-containing granules were found in magnetotactic cocci. The most common consisted of phosphorus-rich granules containing P, O, and Mg; and sometimes also C, Na, Al, K, Ca, Mn, Fe, Zn, and small amounts of S and Cl were also found. In phosphorus-sulfur-iron granules, P, O, S, Na, Mg, Ca, Fe, and frequently Cl, K, and Zn, were detected. Most cells had two phosphorus-rich granules, which were very similar in elemental composition. In rod-shaped bacteria, these granules were positioned at a specific location in the cell, suggesting a high level of intracellular organization. Polyhydroxyalkanoate granules and sulfur globules were less commonly seen in the cells and had no fixed number or specific location. The presence and composition of these intracellular structures provide clues regarding the physiology of the bacteria that harbor them and the characteristics of the microenvironments where they thrive. [Int Microbiol 2005; 8(2):111-117]