Compositions and methods for treating contaminated water

Abstract

A recombinant Moringa oleifera coagulant protein (MO) produced and secreted by Bacillus has coagulation/flocculation activity. The MO protein and the Bacillus host cells expressing the MO protein can be used in compositions and methods for treating contaminated water, such as drinking water or waste water. The MO protein can coagulate or flocculate suspended solid impurities in the water, which can then be removed.

What is claimed is: 
     
         1 . A recombinant  Moringa oleifera  MO protein having coagulation or flocculation activity, wherein the MO protein is produced and secreted by  Bacillus.    
     
     
         2 . The recombinant MO protein of  claim 1 , further comprising a  Bacillus  signal peptide (SP) fused or linked to the MO protein. 
     
     
         3 . The recombinant MO protein of  claim 2 , wherein the SP is at least one selected from the group consisting of: YngK (SEQ ID NO: 5), YxiT (SEQ ID NO: 6), PhrG (SEQ ID NO: 7), YklxW (SEQ ID NO: 8), YycP (SEQ ID NO: 9), YqxI (SEQ ID NO: 10), YkwD (SEQ ID NO: 11), YraJ (SEQ ID NO: 12), AspB (SEQ ID NO: 13), YybN (SEQ ID NO: 14), AprE (SEQ ID NO: 15), YjdB (SEQ ID NO: 16), YxaK (SEQ ID NO: 17), and YusW (SEQ ID NO: 18). 
     
     
         4 . The recombinant MO protein of  claim 1 , further comprising an affinity tag. 
     
     
         5 . A composition for treating contaminated drinking water, the composition comprising a recombinant  Moringa oleifera  MO protein having coagulation or flocculation activity, wherein the MO protein is produced and secreted by  Bacillus.    
     
     
         6 . The composition of  claim 5 , further comprising one or more additional coagulant, flocculent, disinfectant and/or coagulant aid. 
     
     
         7 . The composition of  claim 5 , wherein the composition is in unit dosage form for treating of a relatively small predetermined volume of contaminated drinking water. 
     
     
         8 . The composition of  claim 7 , where the composition is in unit dosage form for treating a volume of contaminated drinking water in a range of from about 0.1 to about 100 liters. 
     
     
         9 . The composition of  claim 7 , wherein the unit dosage is in a form of a solid powder, granules, a tablet, a water soluble single or multi-compartment pouch, or a single or multi-compartment sachet that is opened prior to use. 
     
     
         10 . A method for treating contaminated drinking water, comprising contacting the water with an effective amount of a composition comprising a recombinant  Moringa oleifera  MO protein having coagulation or flocculation activity, wherein the MO protein is produced and secreted by  Bacillus.    
     
     
         11 . The method of  claim 10 , comprising:
 contacting the composition to the contaminated drinking water to obtain partially purified water comprising coagulated or flocculated matter;   removing at least part of the coagulated or flocculated matter from the partially purified water by sedimentation, filtration, decanting, flotation, or a combination thereof, to obtain purified water.   
     
     
         12 . The method of  claim 10 , for the batchwise purification and clarification of a relatively small predetermined volume of contaminated drinking water, comprising:
 adding an effective amount of the composition in unit dosage form to the predetermined volume of contaminated water;   dispersing the composition in the water to coagulate and flocculate suspended solid impurities therein;   allowing the dispersed water to stand; and   filtering the water to remove said impurities and to obtain purified water suitable for human consumption.   
     
     
         13 . The method of  claim 10 , wherein the predetermined volume of water is in a range of 0.1 to 100 liters. 
     
     
         14 . The method of  claim 10 , wherein the predetermined volume of water is in a range of 0.5 to 2 liters. 
     
     
         15 . A method for treating contaminated water, comprising contacting the water with an effective amount of recombinant  Bacillus  cells, the  Bacillus  cells comprising a vector or nucleic acid construct encoding a recombinant  Moringa oleifera  MO protein fused or linked to a  Bacillus  signal peptide (SP), the MO protein having coagulation or flocculation activity, the  Bacillus  cells expressing and secreting the MO protein. 
     
     
         16 . The method of  claim 15 , wherein the vector or nucleic acid construct comprises SEQ ID NO: 1, or a sequence having one or more codons of SEQ ID NO: 1 optimized for expression of the MO protein in  Bacillus.    
     
     
         17 . The method of  claim 15 , wherein the vector or nucleic acid construct comprises SEQ ID NO: 3, or a sequence having at least 70% sequence identity to SEQ ID NO: 3. 
     
     
         18 . The method of  claim 15 , wherein the SP is at least one selected from the group consisting of: 
       
         
           
                 
                 
               
                     
                   (SEQ ID NO: 5) 
                 
                     
                   YngK, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 6) 
                 
                     
                   YxiT, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 7) 
                 
                     
                   PhrG,  
                 
                     
                     
                 
                     
                   (SEQ ID NO: 8) 
                 
                     
                   YklxW, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 9) 
                 
                     
                   YycP, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 10) 
                 
                     
                   YqxI, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 11) 
                 
                     
                   YkwD, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 12) 
                 
                     
                   YraJ, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 13) 
                 
                     
                   AspB, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 14) 
                 
                     
                   YybN, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 15) 
                 
                     
                   AprE, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 16) 
                 
                     
                   YjdB, 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 17) 
                 
                     
                   YxaK, 
                 
                     
                   and 
                 
                     
                     
                 
                     
                   (SEQ ID NO: 18) 
                 
                     
                   YusW. 
                 
             
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         19 . The method of  claim 15 , wherein the recombinant  Bacillus  cells are capable of growing and dividing in the contaminated water. 
     
     
         20 . The method of  claim 15 , wherein the  Bacillus  cells are one or more of  B. alkalophilus, B. amyloliquefaciens, B. brevis, B. circulans, B, clausli, B. coagulans, B. firmus, B. lautus, B. lentus, B. licheniformis, B. megaterium, B. pumilus, B. stearothermophilus, B. subtilis , or  B. thuringiensis  cells.