Novel bacterial phytases and method for producing same

Abstract

The invention concerns novel bacterial phytases, and their respective production methods. More particularly, the invention concerns novel phytases derived from bacteria of genus Acidocella , and polynucleotides coding for said phytases. The invention also concerns vectors containing said polynucleotides, and transformed host organisms expressing said phytases in their tissues. The invention further concerns novel bacterial extracts comprising at least a phytase activity.

1 . A phytase selected from the group consisting of:
 (a) a phytase comprising the amino acid sequence set forth in SEQ ID NO:2;   (b) a phytase having at least 50% sequence homology with the phytase of (a); and   (c) a fragment of the phytase according to (a) or (b).   
     
     
         2 . The phytase as claimed in  claim 1 , wherein the phytase originates from a bacterium of the  Acidocella  genus. 
     
     
         3 . The phytase as claimed in  claim 2 , wherein its optimum pH for activity is less than or equal to 4. 
     
     
         4 . A method for producing a phytase as claimed in  claim 1 , the method comprising:
 (a) culturing a bacterial strain of the  Acidocella  genus,   (b) concentrating the bacteria cultured in step (a),   (c) grinding the bacteria isolated in step (b),   (d) centrifuging the ground material obtained in step (c),   (e) recovering the supernatant having the phytase activity derived from step (d), and   (f) purifying the phytase from the supernatant recovered in step (e).   
     
     
         5 . A method for producing a phytase as claimed in  claim 1 , the method comprising:
 (a) culturing a bacterial strain of the  Acidocella  genus,   (b) recovering the culture medium by removing 10 bacteria, and   (c) purifying the phytase from the culture medium recovered in step (b).   
     
     
         6 . An enzymatic composition comprising at least one phytase as claimed in  claim 1 . 
     
     
         7 . A method for increasing the assimilation of the inorganic phosphate contained in the phytase of plant-based foodstuffs by monogastric animals, wherein the phytase as claimed in  claim 1  is incorporated into the nutrition of said animals. 
     
     
         8 . A method for increasing the assimilation of the inorganic phosphate contained in the phytase of plant-based foodstuffs by a monogastric animal, the method comprising feeding the animal a feed composition comprising at least one phytase as claimed in  claim 1 . 
     
     
         9 . A method for decreasing the addition of phosphorus to monogastric animal nutrition, the method comprising feeding animals with a feed composition comprising at least one phytase as claimed in  claim 1 . 
     
     
         10 . A method for decreasing the phosphorus waste derived from monogastric animal nutrition, the method comprising feeding animals with a feed composition comprising at least one phytase as claimed in  claim 1 . 
     
     
         11 . A method of providing nutrition to a monograstric animal, comprising providing a feed composition comprising at least one phytase as claimed in  claim 1  to said monogastric animal. 
     
     
         12 . The method of  claim 11 , wherein the feed composition comprises a transformed host organism comprising a chimeric gene that encodes the phytase and the host organism is a bacterium of the  Acidocella  genus. 
     
     
         13 . The method of  claim 12 , wherein the host organism is a bacterium selected from the group consisting of  Acidocella aminolytica  and  Acidocella facilis.    
     
     
         14 . The method of  claim 11 , wherein said monogastric animal is selected from the group consisting of pig and poultry. 
     
     
         15 . The method of  claim 11 , wherein said monogastric animal is a pig. 
     
     
         16 . The method of  claim 11 , wherein said monogastric animal is poultry.