Growth response of Basella alba. Linn to Azotobacter species isolated from marine sediments and garden soil

Abstract :

The nitrogenase enzyme is present in diverse lineages of prokaryotes and is generally believed to be within the nif gene, nifH gene which encodes the Fe protein component of nitrogenase enzyme. In the present study, around 11 Azotobacter strains were isolated and identified using routine microbiological techniques. Different nifH primers were used for the study of Azotobacter sp from the marine region by PCR technique. The genomic DNA of the Azotobacter isolates and reference were extracted and assayed by biophotometer. It was observed that the DNA samples were pure and their concentrations ranged from 0.705 to 0.88 mg/ml. It was revealed that the nifH gene was amplified by specific and universal primers whereas non-specific primer does not amplify the gene. The intensity of the amplified product was more when universal primer was used in strains TA1 and MA 378 than other isolates at the range of 370 bp. The genus specific primer (Primer 3) produced band at the range of 390bp for all the isolates. This showed 100% homogeneity with nifH genes among marine Azotobacter sp. recorded. Yet another genus specific primer (Primer 4) was more specific and amplified at the range of 370 bp for the most of the isolates. It was analogous to that of Primer 3 by producing clear identical bands; however, synthesis of sequences (370bp) resembled that of Primer 2. It was clearly showing a high degree of homogeneity among the strains.