Isolation and molecular characterization of phosphate solubilizing Enterobacter and Exiguobacterium species from paddy fields of Eastern Uttar Pradesh, India

Abstract

Six phosphate solubilizing bacteria (PSB) were isolated from paddy fields of Eastern Uttar Pradesh, India harboring low available phosphorus. Taxonomic delineation employing morphological, biochemical, 16S rRNA gene sequences and phylogenetic affiliations suggests that they are members of Enterobacter andExiguobacterium genera. Of the six isolates, Enterobacter sp. LCR1 and LCR2 exhibited high level (568 - 642 μg/ml) of phosphate solubilization in NBRIP liquid medium. Exiguobacterium sp. LCR4 and LCR5 showed increased phosphate solubilization efficiency under alkaline pH while Enterobacter sp. LCR3 remained unaffected. At high salt and temperature, Enterobacter sp. LCR1 and LCR2 produced 1.6 fold soluble phosphorus in comparison with earlier studies. Thus, these isolates may be useful for the development of potential bio-inoculants for soils having alkaline pH, high salt, temperature and insoluble phosphorus.   Key words: Phosphate solubilizing bacteria, phylogenetic analysis, Enterobacterspp., Exiguobacterium spp., 16S rRNA gene sequencing.