Preparation of nanofertilizer from biogenic Zn-nanoparticles synthesized by Azotobacter spp. and its impact on growth promotion of Coriandrum sativum

Abstract

Two isolates of Azotobacter spp. were isolated from the agricultural soil habitat of Jejuri village, Pune, Maharashtra, and identified by morphological characterization and biochemical tests. Zinc nanoparticles (Zn NPS) were synthesized from Azotobacter spp. and characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and FESEM. XRD analysis showed the nanocrystalline form of zinc oxide NPs, and the Scherrer equation determined a mean crystalline size of ~42 nm. The FESEM spectra revealed the spherical shape and agglomeration of the biosynthesized nanoparticles. Various functional groups were involved in the capping and stabilization of the zinc oxide NPs, which were confirmed by FTIR analysis. A pot experiment was formulated to study the effect of nanofertilizer prepared from zinc nanoparticles on parameters such as the height of the plant, length of shoot, length of root, and dry weight of leaves of Coriandrum sativum (coriander plant). Also, parameters like Photosynthetic pigments, hormones, sugars, polyphenols, and proteins were tested. Mean values of measurements recorded on the 9^th, 10^th, 11^th, and 12^th day along with ∓ standard deviation (∓SD), and percentage gain relative to control measurements are computed and reported. It was found that on 12^th day increase in height of plant, length of shoot, length of root, and dry weight of leaves in percentage are 9.24, 9.84, 10.86, and 11.71 respectively. On 9^th, 10^th, 11^th days the growth pattern is same. To strengthen these results advanced statistical analysis, say analysis of variance (ANOVA), is carried out and found that growth in height of plant, height of shoot, height of root, and weight of dry leaves are significantly increasing with respect to increasing in days as well as increasing concentrations of nano fertilizer. Further, to test significant differences in mean chlorophyll contained in both the types of chlorophyll ‘a’ and chlorophyll ‘b’ a t-test for equality of population means is applied and results are reported. The results revealed that the nanofertilizer is responsible for enhancing plant growth and health.