Identification and antagonism activity of an inorganic phosphorus-dissolving bacterial strain isolated from cold region

Abstract:

[Objective] In order to find strains suitable for the development of biocontrol agents and biophosphate fertilizer, bacteria with high phosphorus-dissolving efficiency were isolated from the rhizosphere soils of different crops planted in the cold region of north China.[Methods] A highly effective phosphorous-dissolving bacterium was obtained from 26 bacterial strains with phosphorous-dissolving activity through preliminary and second screening. The bacterial strain was identified through physiological, biochemical and molecular biological methods, and its phosphorus-dissolving activity was tested by molybdenum blue colorimetry method. Meanwhile, the antagonism activity to several plant pathogens was determined by plate confrontation method.[Results] Strain B51-7 was obtained by the screening and identified as Burkholderia sp.. The soluble phosphorus content of the strain B51-7 in the fermentation broth reached 832.7 mg/L. Meanwhile, this strain had a broad-spectrum antifungal activity with the highest antagonism rate of 89.71%. A pot experiment showed that the growth of rice was significantly promoted by inoculation of strain B51-7.[Conclusion] Strain B51-7 was a highly effective phosphate-dissolving bacterium with biological control effect, and could be applied for making biological fertilizers and biocontrol agents.