Bacterial effects on metal accumulation by plants

Abstract

The invention includes methods for (1) extracting metals from soil by the use of plants that extract and accumulate the metal and adding bacteria to the soil that enhances the ability of the plants to extract the metal, and (2) preparing soil for extraction of a metal by plants by adding bacteria to the soil that enhances the ability of plants to extract the metal. It is preferred that the plants be planted in the soil as seeds and that the bacteria added to the soil is also added to the seeds prior to planting.

1 . A method of preparing soil that contains a metal for the extraction of the metal by a plant, the method comprising adding one or more enhancing-bacteria strains to the soil wherein at least one of the enhancing-bacteria strains increases the ability of the plant to accumulate the metal.  
     
     
         2 . The method of  claim 1  that further includes the step of growing the enhancing-bacteria.  
     
     
         3 . The method of  claim 1  wherein the metal is nickel.  
     
     
         4 . The method of  claim 1  wherein the plant is from the genus  Alyssum.    
     
     
         5 . The method of  claim 4  wherein the plant is  Alyssum murale.    
     
     
         6 . The method of  claim 1  wherein the enhancing-bacteria comprises one or more of the group consisting of  M. arabinogalactanolyticum  and  M. liquefaciens.    
     
     
         7 . The method of  claim 1  wherein the enhancing-bacteria comprises rhizobacteria.  
     
     
         8 . The method of  claim 7  wherein the enhancing-bacteria comprises  M. arabinogalactanolyticum.    
     
     
         9 . The method of  claim 7  wherein the enhancing-bacteria comprises  M. liquefaciens.    
     
     
         10 . The method of  claim 1  wherein the plants are planted in the soil as seeds.  
     
     
         11 . The method of  claim 10  wherein the enhancing-bacteria is added to the seeds as well as to the soil.  
     
     
         12 . The method of  claim 11  wherein the enhancing-bacteria comprises rhizobacteria.  
     
     
         13 . The method of  claim 12  wherein the enhancing-bacteria comprises  M. arabinogalactanolyticum.    
     
     
         14 . The method of  claim 12  wherein the enhancing-bacteria comprises  M. liquefaciens.    
     
     
         15 . The method of  claim 12  wherein the seeds are surface sterilized before the enhancing-bacteria is added to the seeds.  
     
     
         16 . The method of  claim 11  wherein the seeds are of  Alyssum murale.    
     
     
         17 . The method of  claim 1  wherein the soil includes organic material in addition to the bacteria.  
     
     
         18 . The method of  claim 1  wherein the soil includes silt.  
     
     
         19 . The method of  claim 1  wherein the soil includes clay.  
     
     
         20 . The method of  claim 1  wherein the soil includes sand.  
     
     
         21 . The method of  claim 1  wherein the soil includes one or more from the group consisting of nickel, copper, zinc, potassium, manganese, phosphorus, magnesium and cadmium.  
     
     
         22 . The method of  claim 1  wherein the soil is nonsterile.  
     
     
         23 . The method of  claim 1  wherein the soil is autoclaved before the enhancing-bacteria is added to the soil.