CHARACTERIZATION OF MORPHOSPECIES AND STRAINS OF MICROCYSTIS (CYANOBACTERIA) FROM NATURAL-POPULATIONS AND LABORATORY CLONES USING CELL PROBES (LECTINS AND ANTIBODIES)

The genus Microcystis (cyanobacteria) includes toxic and bloom-forming morphotypes which are usually arranged into species based on morpholo gical features. Immunofluorescence assays using polyclonal and preadso rbed antibodies, as well as FITC-labeled lectins were used to characte rize three morphospecies of Microcystis (M. viridis, M. wesenbergii, a nd M. aeruginosa) from natural populations (several lakes/reservoirs i n Denmark and Spain) and laboratory clones. The cell probes used were unaffected by the different phases of the cell division cycle, growth phase, or environmental factors, such as culture medium, light, or tem perature. Antibody and lectin binding patterns were specific to each c lone. In nature, the cell probes were useful tools to characterize Mic rocystis populations. Antibodies and lectins revealed geographic diffe rentiation within the same morphospecies. Differentiation was moderate among nearby locales and intensified among areas distant from one ano ther. Microcystis aeruginosa from Spain has very different cell surfac e antigens and lectin binding sites than M. aeruginosa from Denmark. A taxonomy of Microcystis based on cell probes reveals some discrepanci es with classical morphospecies. The binding affinities were more clos ely related to the geographic origin of the tested material than to th e morphospecies identification. Different morphospecies from the same lake in some cases were more similar than the same morphospecies from different lakes. Microcystis viridis and M. aeruginosa from Danish lak es appeared to be closely related species, whereas M. wesenbergii emer ged as a different species.