The bacterium Burkholderia has been isolated from the rhizosphere soils of Mimosa, Lemon, Maize, Sugarcane, Sunfl ower, Rice, Bhendhi, Sunhemp, Co on and Chilly from the diff erent farms of Tamil Nadu Agricultural University, Coimbatore. Biochemical and physiological characterization was done for the obtained isolates to screen for further studies by using starch hydrolysis, lipid hydrolysis, casein hydrolysis and catalase test, etc. The isolates were checked for their ability to fi x nitrogen by using diff erent medium like BMGM and N free BMGM medium. The isolates were also checked for nitrogenase activity by using gas chromatography. B1 and R1 isolates showed high nitrogenase activity (7.99 and 7.15 n moles of ethylene /hr./mg of cell protein respectively). Total genomic DNA was isolated and PCR with 16S rRNA gene specifi c primers carried out to yields amplicons of 1300 bp size in Burkholderia. The PCR was carried out with specifi c primers of nifH gene primer for selected isolates. It showed that selected four isolates were found to have nifH gene with 400 bp. The present study revealed that some

of the Burkholderia sp. helps in plant growth promoting activities by fi xing nitrogen to enhance the yield of crop plants that can be exploited as bioinoculant in agriculture