Affiliation:
1. National Institute of Molecular Biology and Biotechnology, University of the Philippines Los Baños, Los Baños 4031, Laguna, Philippines
Abstract
Phosphorus (P) solubilization is one of the major traits for plant growth-promoting rhizobacteria since P is easily rendered insoluble in soil. Phosphate-solubilizing microorganisms can be harnessed as an environment-friendly strategy to enhance the mobilization and acquisition of P by crops. Utilization of such microorganisms as microbial inoculants in agriculture serves as an alternative to chemical fertilizers and an approach for more efficient P fertilization. Hence, this study aims to characterize a phosphate-solubilizing isolate and evaluate its potential as a microbial inoculant. Morphological, biochemical, and genetic characterization of the isolate were performed. Then, the mineral phosphate solubilization ability of the isolate was evaluated. Lastly, this study evaluated the plant growth promotion of the isolate as a single inoculant in rice or as a co-inoculant with rhizobia in peanuts. On the basis of biochemical and 16S rRNA analysis, the isolate was identified as Enterobacter sp. Also, it can solubilize P from tricalcium phosphate or aluminum phosphate. Simultaneous with P solubilization, medium acidification, and gluconic acid secretion were observed. Lastly, the Enterobacter sp. isolate could potentially be developed as a biofertilizer in reducing P resource input or to enhance the performance of a rhizobia inoculant.