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Plant and Soil

, Volume 109, Issue 1, pp 115–121 | Cite as

Electron microscopic studies of aggregation and pellicle formation inAzospirillum spp.

  • Lea Madi
  • M. Kessel
  • Ester Sadovnik
  • Y. Henis
Article

Abstract

Microscopic studies on aggregation ofAzospirillum brasilense Cd and the local isolate Cd-1 revealed the presence of an extracellular layer (ECL) on the outer surface of cells taken from the early exponential phase. Incubation of the bacteria with cationized ferritin (CF) was followed by labelling of the ECL of both Cd and Cd-1 taken from the stationary phase. Concanavalin-A-ferritin (Con-A-F), a lectin conjugated with ferritin, was bound to the ECL which was developed during the stationary phase, but not the exponential phase, in both isolates. In static liquid cultures,Azospirillum brasilense Cd formed lateral flagella and fimbriae-like structures which were not observed in shaking liquid cultures. It is suggested that these filaments may play a role in cell-to-cell adhesion of Azospirillum that results in pellicle formation observed in static cultures.

Key words

cationized ferritin extracellular layer fimbriae pellicle formation 

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Copyright information

© Kluwer Academic Publishers 1988

Authors and Affiliations

  • Lea Madi
    • 1
  • M. Kessel
    • 1
  • Ester Sadovnik
    • 1
  • Y. Henis
    • 1
  1. 1.Department of Plant Pathology and Microbiology, Faculty of AgricultureThe Hebrew University of JerusalemRehovotIsrael

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