Fabrication and characterization of nano-hydroxyapatite particles and assessment of the effect of their supplementation on growth of bacterial root endosymbionts of cowpea

Abstract

The overall goal of this research was to evaluate the effect of nanohydroxyapatite (nHA) particles on the growth of endophytic root nodule symbionts of vegetable cowpea. The synthesized nHA exhibited spherical to hexagonal shaped morphology, the size range of 6–15 nm, and had irregular aggregate structures as confirmed by scanning and transmission electron microscopy techniques. The XRD and FTIR spectroscopy studies revealed the nano-crystallite nature and presence of phosphate functional group. Among the six nHA concentrations (0, 12, 25, 50, 75, and 100 mg L−1) the highest concentration resulted in maximum growth of Burkholderia seminalis CP-RN-4 and reference culture as observed by Visible spectroscopy and viable cell count analysis. Scanning Electron Microscopy analysis of broth cultured bacterial cells showed alteration in cell size in both cultures in presence of nHA besides production of copious amount of exopolysaccharide indicated through formation of cell aggregates/biofilm primordia.