Induction of flocculation in photosynthetic organisms

Abstract

The present invention provides compositions and methods for producing flocculation moieties in photosynthetic organisms. The photosynthetic organisms are genetically modified to effect production, secretion, or both, of the flocculation moieties. Also provided are methods of flocculating organisms.

1 .- 27 . (canceled) 
     
     
         28 . A method of flocculating a non-vascular photosynthetic organism, comprising
 expressing an exogenous nucleic acid encoding a first flocculation moiety as a cell surface component of a first non-vascular photosynthetic organism; and   contacting said organism with a second flocculation moiety, thereby flocculating said organism.   
     
     
         29 . A method of flocculating a non-vascular photosynthetic organism, comprising contacting said non-vascular photosynthetic organism with a second organism, said second organism comprising an exogenous nucleic acid encoding a flocculation moiety that binds to a surface component of said non-vascular photosynthetic organism thereby causing flocculation of said non-vascular photosynthetic organism. 
     
     
         30 . The method of  claim 28 , further comprising transforming a second organism with a second exogenous nucleic acid encoding said second flocculation moiety; and expressing said second flocculation moiety. 
     
     
         31 . The method of  claim 28 , wherein said first flocculation moiety is a carbohydrate binding protein or an antibody. 
     
     
         32 . The method of  claim 29 , wherein said flocculation moiety is a carbohydrate binding protein or an antibody. 
     
     
         33 . The method of  claim 30 , wherein said second flocculation moiety is a carbohydrate binding protein or an antibody. 
     
     
         34 . The method of  claim 31 , wherein said carbohydrate binding protein is a lectin. 
     
     
         35 . The method of  claim 34 , wherein said carbohydrate binding protein is selected from the group consisting of DC-SIGN, dectin-1, dectin-2, HECL, langerin, layilin, mincle, MMGL, E-selectin, P-selectin, L-selectin, DEC-205, Endo 180, mannose receptor, phospholipase A2 receptor, sialoadhesin (siglec-1), siglec-2, siglec-3, siglec-4, siglec-5, siglec-6, siglec-7, siglec-8, siglec-9, siglec-10, siglec-11, and galectins. 
     
     
         36 . The method of  claim 28 , wherein (i) said second flocculation moiety interacts with said first flocculation moiety and said second flocculation moiety is a lectin, carbohydrate, protein, heavy metal, cationic or chemical flocculant; or (ii) said second flocculation moiety is attached to a solid support. 
     
     
         37 . The method of  claim 31 , wherein (i) said antibody specifically binds a cell surface antigen; or (ii) said antibody is a univalent, multivalent or polyvalent antibody. 
     
     
         38 . The method of  claim 28 , wherein at least one of said exogenous nucleic acids further comprises a regulatory element, said element comprising a constitutive promoter, a light-inducible promoter, a quorum-sensitive promoter, temperature-sensitive promoter, a salt sensitive promoter, or a nitrogen concentration responsive promoter. 
     
     
         39 . The method of  claim 28 , wherein (i) said second organism is the same species as said first organism; or (ii) said second organism is a different species from said first organism. 
     
     
         40 . The method of  claim 30 , wherein at least one of said exogenous nucleic acids further comprise a targeting element that allows said first flocculation moiety, said second flocculation moiety, or both to be directed to an external surface of said organism. 
     
     
         41 . The method of  claim 30 , wherein at least one of said exogenous nucleic acids further comprise a sequence encoding an anchoring element that allows anchoring of said first flocculation moiety, said second flocculation moiety, or both on an external surface of said first organism, said second organism or both. 
     
     
         42 . The method of  claim 29 , wherein said flocculation moiety is secreted by said second organism.