A new method for biological synthesis of agriculturally relevant nanohydroxyapatite with elucidated effects on soil bacteria

Abstract

The study describes a novel and environment friendly route of biosynthesis of nanohydroxyapatite (nHAP). Bacillus licheniformis mediated synthesis of nHAP has been carried out with different phosphate concentrations (2%, 5%, 10% and 20% w/v) of potassium dihydrogen orthophosphate monobasic (K2HPO4). The synthesis is supported by a two-step mechanism – (i) solubilization of P by organic acids extracellularly secreted by the bacterial strain and (ii) gelation of P and Ca. The nHAP particles were characterized using electron microscopy and XRD analysis. Powdered crystalline particles with a size range of 30 ± 5 nm were obtained with shape and size dependent on phosphate concentrations. The particles showed no adverse effect on plant growth-promoting bacteria. Evaluation of nHAP prepared by this route with 2% P source provides scope for a wide range of applications, especially as a nano-fertilizer.

Fabrication and characterization of eco-friendly composite materials from natural animal fibers

“…For the appearance of the OH group, a peak was emerged in the wavenumber of 3400 cm −1 . All the peak positions were more or less similar to the literature [ 37 , 38 , 39 , 40 ]. FTIR data of hair fiber-reinforced UPR based-composites are represented in Figure 7 .…”

Fertilizing benefits of biogenic phosphorous nanonutrients on Solanum lycopersicum in soils with variable pH

“…Biologically generated nHAP and chemically synthesized nHAP were produced in-house using previously published methods [ 28 ]. Both of these NMs have also been characterized for physicochemical properties in our previous study using transmission electron microscopy, dynamic light scattering, FTIR and XRD [ 28 , 33 ].…”

“…Another important aspect to consider when applying these NMs to agriculture fields is a reduction in secondary contamination as well as environmental load, which occurs due to the use of harsh acidic or basic conditions while synthesizing the NMs. A more environmentally friendly approach to the synthesis of P-based NMs can be achieved using biological synthesis routes [ 28 , 29 , 30 ]. The biological synthesis of NMs via the use of different plant extracts [ 29 , 30 ] and non-pathogenic soil microorganisms [ 28 ] is hypothesized to eliminate the need for stringent chemicals and is considered a greener and more sustainable approach.…”

“…A more environmentally friendly approach to the synthesis of P-based NMs can be achieved using biological synthesis routes [ 28 , 29 , 30 ]. The biological synthesis of NMs via the use of different plant extracts [ 29 , 30 ] and non-pathogenic soil microorganisms [ 28 ] is hypothesized to eliminate the need for stringent chemicals and is considered a greener and more sustainable approach.…”

“…This study reports the fertilizing effects of biogenic P-based NMs in soils under different pH levels. These biogenic P-based NMs have been demonstrated to have no acute toxicity in plant-growth promoting rhizobacteria [ 28 ], Caenorhabditis elegans [ 33 ] and zebrafish embryos [ 77 , 78 ]. Solanum lycopersicum (Pusa Rohini, Indian tomato variety), a dicot species was chosen for this study.…”