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….$CLONES$OF$MICROCYSTIS$AERUGINOSA$USING$LECTINS$

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(Table!3).!In!contrast,!the!blooms!with!higher!amount!of!microcystin!exhibited!the!
lowest!percentage!of!UEA?1!labelled!colonies.!

Table$ 3.B!Relation!between!the!percentage!of!M.!aeruginosa!colonies!negatively!labelled!by!UEA?1!
lectin!from!each!bloom!and!the!water!toxicity!observed!in!each!blooms.!

Bloom$from$ %$of$colonies$with$negative$ Water$toxicity$(in$
label$by$UEAB1$lectin$$ µg/L$microcystin$

(microcystinBproduccing)$ LR$equivalent)$

El$Gergal$ 9%! 0.4!

La$Minilla$ 4%! 0.1!

Cuerda$del$Pozo$ 29%! 1.9!

Doñana$National$Park$$ 63%! 4.3!

!

4.*DISCUSSION*

During! the! last! decades! numerous! fields! of! microbiology! have! been!
increased!use!of!lectins.!The!interactions!of!lectins!with!microorganisms!have!been!
widely!applied!for!the!examining!of!bacteria!and!protists!(47).!!

Despite! little! is! known! about! the! biological! function! of! lectins! in!
cyanobacteria.! Apparently,! Microcystis! lectins! seem! to! play! a! role! in! cell?cell!
recognition! and! aggregation! of! single! cells! to! colonies! (58).! There! also! appears! to!
be! a! functional! association! between! microcystin! production! and! lectins.! In!
particular,! microcystin! has! an! impact! on! the! expression! of! MNV! lectin! of!
Microcystis!(58).!!

Despite! of! our! lack! of! knowledge! about! numerous! details! concerning! the!
biological!function!of!lectins!in!cyanobacteria,!the!property!of!lectins!to!bind!non?
covalently! to! simple! sugar! and! polysaccharides! could! be! a! practical! method! to!
discriminate! among! different! cyanobacteria! strains! as! well! as! to! discriminate!
between! toxin?produccing! and! non?toxic! M.)aeruginosa! strains.! Ever! since! Costas!
and!López?Rodas!(1994)!(48),!the!importance!of!lectins!distinguish!toxic!and!non?
toxic! PSP?producing! strains! of! marine! dinoflagellates! is! well! known,! despite!
biological!function!of!lectins!in!toxic!dinoflagellates!was!not!completely!elucidated!
at! this! moment.! Despite! the! promising! results! obtained! from! the! use! of! lectins!
differing! clones! of! cyanobacteria,! this! procedure! is! not! currently! a! routine!
technique!in!water!supply!enterprises!(56,!57).!!

Several! works! characterizing! lectin?binding! pattern! show! that! M.)
aeruginosa!strains!differ!in!their!surfaces!properties!(59?61).!!It!has!been!observed!
that! M.) aeruginosa! populations! could! comprise! large! clonal! families,! anywhere!

131$

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