Isolation and characterization of nitrogen fixingburkholderiaSp.

Abstract

The bacterium Burkholderia has been isolated from the rhizosphere soils of Mimosa, Lemon, Maize, Sugarcane, Sunflower, Rice, Bhendhi, Sunhemp, Co on and Chilly from the different 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 fix nitrogen by using different 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 specific primers carried out to yields amplicons of 1300 bp size in Burkholderia. The PCR was carried out with specific 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 fixing nitrogen to enhance the yield of crop plants that can be exploited as bioinoculant in agriculture.