Biosynthesis of Nano-Calcite and Nano-Hydroxyapatite by the Probiotic Bacteria of Bacillus subtilis and Bacillus coagulans

In recent years, green synthesis of nanobiomaterials has received more attentions than chemical synthesis due to their ecofriendly and compatibility. The aims of this study were to investigate synthesis of nanobiomaterials from probiotics and characterize these nanobiomaterials.

Bacillus subtilisand Bacillus coagulanswere cultured in media containing insoluble calcium phosphate and urea, and produced nano-hydroxyapatite and nano-calcite. Productions were surveyed in three stages. First, produced particles were assessed on the surface of the dried bacteria at room temperature. In the second stage, dried bacteria were burned at 600ºC. In the final stage, hydroxyapatite was purified using nanofilters. Characterization and elemental analysis of the biomaterials were studied using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectroscopy, energy dispersive X-ray and X-ray fluorescence.

It was shown that nano-calcite and braided nano-hydroxyapatite on the dried biomass surface and nano-hydroxyapatite were made only in media containing insoluble calcium phosphate supplemented by urea, which was induced by phosphatase and urease. Removing organic matters by heat treatment led to the further purity of the particles. The X-ray fluorescence results revealed purity of the nano-hydroxyapatite, which was achieved by filtration of particles after burning. The ratio of calcium to phosphorus in B. coagulance sample reached 1.8, which was close to stoichiometric hydroxyapatite.Sincenanobiomaterials are made from probiotics, these particles can be appropriate candidates to use in food industries, sanitation and medicine. Braided nano-hydroxyapatite can substitute needle-like types of food additives for infants and elderly people because of its safety