Characterization of mangrove associated nitrogen fixing halophilic bacterium paenibacillus sp.

Conservation of mangrove through improved mangrove nursery technologies using bacterial bio-fertilizers will be appropriate solution for deforestation. Members of the genus Paenibacillus widely reported for its nitrogen fixing character from various environments. In this study we identified a halophilic nitrogen fixing bacterium from Pichavaram mangrove rhizosphere soil of Avicennia marina, which is dominant flora in the forest. The bacterium showed 2017±32.60 nmol ethylene mg protein-1 of nitrogenase activity hence it is highly comparable with all other nitrogen fixers reported in the genus. Further the bacterium characterized by 16S rRNA gene sequence and phenotypic characters. 16S rRNA gene sequence showed 98% similarity with P. xylanexeden and P. amylolyticus whereas 99% similarity with P. pabuli, however phenotypic characters are totally differed from these three species. On the other hand phenotypic characters fairly comparable with nitrogen fixing P. brasilensis but showed only 94% similarity in 16S rRNA gene sequence. Hence the bacterium was named as Paenibacillus sp. BPRIST073. This study indicated the first time in reporting the occurrence of nitrogen fixing Paenibacillus from mangrove rhizosphere.