Isolation,Identification and Resistant Features of a Siderophores Producting Bacteria from Peanut Rhizosphere

Objective:To isolate and identify a siderophores producing bacterium from the peanut rhizosphere.Methods:Strains were isolated from peanut rhizosphere by gradient dilution,and then siderophores producing bacterium was screened out based on the chrome azurol S(CAS) assay.This strain was identified based on the characteristics of morphological,cultivation,physiology,and the 16S rDNA sequence;9 familiar antibiotics were examined by using antibiotic gradient plates.Results:A siderophores producing bacterium D15 was screened out and 13 physiological and biochemical features were done.All except the M.R assay was according with Pseudomonas putida.Its 16S rDNA sequence was identical to that of P.putida at 100% level.The strain can sustain ampicillin,chloramphenicol,rifampin,erythromycin,neomycin,streptomycin,tetracyclin in different concentrations and showed high sensitive to kanamycin and gentamycin.Conclusion:A siderophores producing bacterium D15 was obtained,which was identified as P.putida.The resistant features of this strain can be used for research genes involved in siderophores synthesize by transposon mutagenesis.