Functional characterization of phosphate solubilizing bacteria of coastal rice soils of Odisha, India

Abstract

In soil, different plant growth-promoting bacteria (PGPB) convert insoluble phosphorus to available forms to plants which helps to enhance crop productivity. Inoculation of phosphate solubilizing bacteria (PSB) as biofertilizer enhances P availability to plants. Therefore, microbial dynamics of coastal rice field soils of Balasore (Chandipur, Talapada and Talasari) and Cuttack (NRRI), Odisha were analyzed, and PSB were isolated, characterized and assessed for plant growth promotion (PGP) functions. The PSB populations in the soils of Chandipur, Talapada, Talasari and Cuttack (NRRI) were 0.2, 2.5, 2.8and 3.6 (×10⁵)cfu/g soil, respectively. Sixteen bacterial isolates were assessed qualitatively for phosphate solubilization, out of which, six more efficient organisms (phenotyped as Bacillus spp.) possessing polyvalent PGP functions viz. nitrogen fixation; IAA, ammonia, siderophore and salicylic acid production, and phosphate mineralization were studied thoroughly. The six PSB possessing the beneficial PGP traits can be exploited as potent biofertilizers to sustain rice production.