Isolation And Identification Of Inorganic Phosphorus-solobiliaing Bacteria By BIOLOG And Molecular Method

Phosphorous nutrition is one of the most important elements to plant growth. Most of phosphorus in the soil is insoluble and can not be absorbed by plant. Phosphorus in chemical phosphorous fertilizer applied into farmland becomes insoluble soon for the combination with Fe³⁺, Ca²⁺ and Al³⁺. Such insoluble phosphates will turn in to soluble ones under the influence of inphosphorus-solubilizing bacteria. Therefore screening strains with high inphosphorous-solubilizing capacity will not only contribute to increase the production of crops, but also positive to decrease the amount of chemical phosphorous fertilizer applied into farm, which is beneficial to avoid pollution from it.This research aims to screen strains with high inphosphorous-solubilizing capacity from soil of plants in Qinling Mountains. And their ability on it are analysed exactly. And we determine their sorts through Biolog and 16S rDNA sequencing. Finally three strains are screened and studied in-depth.(1) The diameter (d) of No.9 strain colony is 10mm and it (D) of phosphorus-solubilizing circle is 43mm. The rate of D/d is3.94. The amount of soluble phosphorus of inorganic phosphorus liquid media, where No.9 strain is cultured in the temperature of 28℃after 5 days, is 98.12 mg/L and it of microbial biomass phosphorus is 62.85 mg/L. The total amount of phosphorus solubilized the bacteria is 160.97 mg/L. The pH value of the media is 6.11. Physiological and biochemical tests show that No.9 strain is gram negative intestinal bacteria. And it is identified as Inquilinus ginsengisoli by 16S rDNA sequencing and the analysis with data from Genebank.(2) The diameter (d) of No.15 strain colony is 9mm and it (D) of phosphorus-solubilizing circle is 35mm. The rate of D/d is3.78. The amount of soluble phosphorus of inorganic phosphorus liquid media, where No.15 strain is cultured in the temperature of 28℃after 5 days, is 80.37 mg/L and it of microbial biomass phosphorus is 53.61 mg/L. The total amount of phosphorus solubilized the bacteria is 133.98 mg/L. The pH value of the media is 5.82. Physiological and biochemical tests show that No.15 strain is gram negative intestinal bacteria. And it is identified as Acinetobacter calcoaceticus by 16S rDNA sequencing and the analysis with data from Genebank. (3) The diameter (d) of No.17 strain colony is 7mm and it (D) of phosphorus-solubilizing circle is 31mm. The rate of D/d is4.41. The amount of soluble phosphorus of inorganic phosphorus liquid media, where No.17 strain is cultured in the temperature of 28℃after 5 days, is 104.91 mg/L and it of microbial biomass phosphorus is 36.59 mg/L. The total amount of phosphorus solubilized the bacteria is 141.5 mg/L. The pH value of the media is 5.82. Physiological and biochemical tests show that No.17 strain is gram negative intestinal bacteria. And it is identified as Pseudomonas fluorescens by 16S rDNA sequencing and the analysis with data from Genebank.