Breeding Efficiently Potassium-solubilizing Bacteria From The Potaasium Mine Of Xiangxi

Soluble potassic resources in our country are scarce,so volume of potash fertilizer should be imported every year,while the insoluble potassic resources,potassium feldspar of the ores are extremely abundant,which are 100 million tons?K₂O?in Xiangxi.So it's significant to find potash feldspar-solubilizing bacteria in a high efficiency and low cost way.In this research,potasg feldspar-solubilizing bacteria were isolated from the potassium mine region of Xiangxi,meanwhile,potassium-releasing activity of potash feldspar-solubilizing bacteria wasdetermined by ICP-OES.In96 hours,potassium-releasing activity of strain L17 was 86.77 mg/L,15.8 times than the CK.Comparinganalysisonallthepotassium-releasingactivityofpotash feldspar-solubilizing bacteria,we would find there were huge differences on potassium-releasing activity between diverse genera of bacteria under the same habitat.Potassium-solubilizing bacteria were identified by bacterial morphology,physiology and biochemical characteristics,and molecular biology based on 16S rRNA gene sequences.38 strains of potash feldspar-solubilizing bacteria were isolates,belonging to13 genera,13 strains were Ensifer and 4 strains were Bacillus,and Ensifer and Bacillus were the dominant species and the potassium-releasing activity was good,which were determine the taxonomic status of potassium-solubilizing bacteria.Then determine the optimal fermentation conditions of potassium-solubilizing bacteria by observe the growth of the taxonomic status of potassium-solubilizing bacteria,as well as the amount of bacteria,potash feldspar particle size,the number of potash feldspar and effect of temperature on the growth potassium-solubilizing bacteria.Access potash feldspar amount was 4 mL,potash feldspar particle size was 150 mesh,potash feldspar addition was 8g and fermentation temperature was 30?.Mutation breeding by using physical and chemical methods,and the UV mutagenesis and NTG mutagenesis were used to the highest-potassium-releasing activity bacteria L17 islated in the work before.Then experiments of the best mutagenesis time and the best mutagenic dose were adopted to determine the optimum mutagenesis conditions.After mutagenesis for three times with the optimum mutagenesis conditions,the potassium-releasing activity of strain L-Z3 and strain L-Y2had larger capacity building,increasing by 106%and 116%respectively compared with the originals.