Rhizobacteria and Uses Thereof

Abstract

The invention relates to the rhizobacterium Bacillus thuringiensis strain AZP2 and the use thereof in improving plant growth and tolerance to biotic and abiotic plant stresses.

1 . A  Bacillus thuringiensis  strain AZP2. 
     
     
         2 . The  Bacillus thuringiensis  strain according to  claim 1  obtainable from pine roots grown on gneiss rock at Mount Lemmon, Ariz., United States of America at latitude and longitude coordinates of N 32° 23.1408′ W 110° 41.6315 at an elevation of 2150 m. 
     
     
         3 . The  Bacillus thuringiensis  strain according to  claim 2  obtainable by a method comprising the steps of:
 homogenizing plant rhizosphere material from said pine roots to form a bacteria containing rhizosphere material; 
 suspending said plant rhizosphere material in a sterile buffer to form a plant material suspension; and 
 inoculating said plant material suspension on a culture plate, optionally comprising cylcoheximide, to form colonies of said  Bacillus thuringiensis  strain AZP2. 
 
     
     
         4 . The  Bacillus thuringiensis  strain according to  claim 3  obtainable by said method further comprising heat treating said plant material suspension at about 80° C. for about 30 minutes, wherein inoculating said plant material suspension comprises inoculating said heat treated plant material suspension on said culture plate. 
     
     
         5 . The  Bacillus thuringiensis  strain according  claim 1  as deposited under depository number MSCL1307. 
     
     
         6 . A plant substrate comprising a  Bacillus thuringiensis  strain according to  claim 1 . 
     
     
         7 . The plant substrate according to  claim 6  selected from a group consisting of soil, peat, compost, vermiculite, perlite, sand or clay. 
     
     
         8 . The plant substrate according to  claim 6  further comprising a  Paenibacillus polymyxa  strain A26 and/or strain A26Δsfp and/or a  Alcaligenes faecalis  strain AF. 
     
     
         9 . A plant seed coated with a  Bacillus thuringiensis  strain according to  claim 1   
     
     
         10 . The plant seed according to  claim 9  further coated with a  Paenibacillus polymyxa  strain A26 and/or strain A26Δsfp and/or a  Alcaligenes faecalis  strain AF. 
     
     
         11 . A plant root coated with a  Bacillus thuringiensis  strain according to  claim 1 . 
     
     
         12 . The plant root according to  claim 11  further coated with a  Paenibacillus polymyxa  strain A26 and/or strain A26Δsfp and/or a  Alcaligenes faecalis  strain AF. 
     
     
         13 . A plant having a plant root according to  claim 11 . 
     
     
         14 . A bacterial composition comprising a  Bacillus thuringiensis  strain according to  claim 1  and at least one of a  Paenibacillus polymyxa  strain A26, a  Paenibacillus polymyxa  strain A26Δsfp and a  Alcaligenes faecalis  strain AF. 
     
     
         15 . A method of improving growth of a plant comprising:
 coating a seed of said plant or a root of said plant with a  Bacillus thuringiensis  strain according to  claim 1 ; and   growing said seed or said rood in a plant substrate.   
     
     
         16 . A method of improving growth of a plant comprising:
 adding a  Bacillus thuringiensis  strain according to  claim 1  to a plant substrate; and   growing a seed or a root of said plant in said plant substrate.   
     
     
         17 . A method of improving tolerance of a plant against osmotic stress comprising coating a seed or a root of said plant with a  Bacillus thuringiensis  strain according to  claim 1 . 
     
     
         18 . A method of improving tolerance of a plant against osmotic stress comprising adding a  Bacillus thuringiensis  strain according to  claim 1  to a plant substrate in which said plant is growing. 
     
     
         19 . A method of improving nutrient composition of a plant substrate comprising adding a  Bacillus thuringiensis  strain according to  claim 1  to said plant substrate. 
     
     
         20 . A method of increasing seed germination rate comprising coating a seed of a plant with a  Bacillus thuringiensis  strain according to  claim 1 . 
     
     
         21 . A method of improving plant P 3+ , K + , Ca 2+  and/or nitrogen contents under stress condition comprising coating a seed or a root of said plant with a  Bacillus thuringiensis  strain according to  claim 1 . 
     
     
         22 . A method of improving plant P 3+ , K + , Ca 2+  and/or nitrogen contents under stress condition comprising adding a  Bacillus thuringiensis  strain according to  claim 1  to a plant substrate in which said plant is growing. 
     
     
         23 . A method of improving growth of a plant comprising:
 coating a seed of said plant or a root of said plant with a bacterial composition according to  claim 14 ; and   growing said seed or said rood in a plant substrate.   
     
     
         24 . A method of improving growth of a plant comprising:
 adding a bacterial composition according to  claim 14  to a plant substrate; and   growing a seed or a root of said plant in said plant substrate.   
     
     
         25 . A method of improving tolerance of a plant against osmotic stress comprising coating a seed or a root of said plant with a bacterial composition according to  claim 14 . 
     
     
         26 . A method of improving tolerance of a plant against osmotic stress comprising adding a bacterial composition according to  claim 14  to a plant substrate in which said plant is growing. 
     
     
         27 . A method of improving nutrient composition of a plant substrate comprising adding a bacterial composition according to  claim 14  to said plant substrate. 
     
     
         28 . A method of increasing seed germination rate comprising coating a seed of a plant with a bacterial composition according to  claim 14 . 
     
     
         29 . A method of improving plant P 3+ , K + , Ca 2+  and/or nitrogen contents under stress condition comprising coating a seed or a root of said plant with a bacterial composition according to  claim 14 . 
     
     
         30 . A method of improving plant P 3+ , K + , Ca 2+  and/or nitrogen contents under stress condition comprising adding a bacterial composition according to  claim 14  to a plant substrate in which said plant is growing.