TYPING OF HALOPHILIC ARCHAEA AND CHARACTERIZATION OF THEIR CELL-SURFACE CARBOHYDRATES BY USE OF LECTINS

Lectins are important tools for cell typing and for the study of cell surface components. They have been widely used for the analysis of car bohydrates on the surface of many eukaryotic and prokaryotic cells, bu t they have nor yet been exploited in the study of the halophilic Arch aea (family Halobacteriaceae), because of the high salinity required f or the structural integrity of these microorganisms. We have defined t he salt concentration threshold high enough for survival of the Archae a, but sufficiently low for lectins to bind to them. Under these condi tions we studied the interactions of a series of lectins, exhibiting d ifferent sugar specificities, with diverse halophilic Archaea. Concana valin A was the most reactive by virtue of its glucose (and mannose) b inding. The other lectins varied in their interactions. The results in dicate that lectins might be useful probes for both archaeal typing an d analysis of their cell surface carbohydrates. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V . All rights reserved.