Thlaspi caerulescens subspecies for cadmium and zinc recovery

Abstract

A cadmium- and zinc-hyperaccumulating subspecies from Thlaspi caerulescens and methods for removing and optionally recovering cadmium and zinc from soil using phytoextracting techniques wherein the subspecies is cultivated on soil containing cadmium and zinc.

1 . A method of recovering cadmium and/or zinc from soil containing cadmium and/or zinc, comprising: 
 (a) cultivating at least one  Thlaspi caerulescens  plant that accumulates from about 1000 to about 6000 mg cadmium/kg above-ground tissues on a dry weight basis and/or from about 15,000 to about 30,000 mg zinc/kg above-ground tissues on a dry weight basis under conditions sufficient to permit said at least one  Thlaspi caerulescens  plant to accumulate such amounts of cadmium and/or zinc; and    (b) recovering the accumulated cadmium and/or zinc.    
   
   
       2 . The method of  claim 1 , wherein the accumulated cadmium and/or zinc is recovered by harvesting said at least one  Thlaspi caerulescens  plant as biomass material after accumulation of cadmium and/or zinc and recovering said cadmium and/or zinc from said biomass material.  
   
   
       3 . The method of  claim 2 , wherein said cadmium and/or zinc is recovered from said biomass material by drying and combusting said harvested biomass material to oxidize and vaporize organic material present.  
   
   
       4 . The method of  claim 2 , wherein said cadmium and/or zinc is recovered from said biomass material by incineration and reduction to ash with energy recovery to give a zinc- and/or cadmium-containing ore.  
   
   
       5 . A zinc and/or cadmium-containing ore produced by the method of  claim 4 .  
   
   
       6 . The method of  claim 1 , wherein said at least one  Thlaspi caerulescens  plant is  Thlaspi caerulescens  G15, the seeds of which have been deposited under ATCC Accession No. 203439.  
   
   
       7 . The method of  claim 1 , wherein the soil is acidified prior to cultivation.  
   
   
       8 . The method of  claim 1 , wherein at least one chloride salt is added to the soil prior to cultivation.  
   
   
       9 . An isolated  Thlaspi caerulescens  plant cultivated on cadmium- and/or zinc-containing soil that accumulates cadmium in above-ground tissue at a concentration of from about 100 mg/kg dry weight of said tissue to about 6000 mg/kg dry weight of said tissue and/or accumulates zinc in above-ground tissue at concentration of from about 5000 mg/kg dry weight of said tissue to about 30,000 mg/kg dry weight of said tissue.  
   
   
       10 . The isolated  Thlaspi caerulescens  plant of  claim 9 , wherein the genotype is  T. caerulescens  G15.  
   
   
       11 . Pollen of the plant of  claim 9 .  
   
   
       12 . A plant having all the physiological and morphological characteristics of the plant of  claim 9 .  
   
   
       13 . Propagation material of the plant of  claim 9 .  
   
   
       14 . A  Thlaspi caerulescens  G15 seed as deposited with the ATCC having Accession No. 203439.  
   
   
       15 . Cultivated  Thlaspi caerulescens  G15, the seeds of which have been deposited under ATCC Accession No. 203439.  
   
   
       16 . A method of decontaminating soil containing cadmium and/or zinc, comprising cultivating at least one  Thlaspi caerulescens  plant that accumulates from about 100 to about 6000 mg cadmium/kg above-ground tissues on a dry weight basis and/or from about 5000 to about 30,000 mg zinc/kg above-ground tissues on a dry weight basis under conditions sufficient to permit said at least one  Thlaspi caerulescens  plant to accumulate such amounts of cadmium and/or zinc.