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

Abstract

Background and objective: In recent years, the green synthesis of nanomaterials has received more attention than chemical synthesis due to its eco-friendly and compatibility. Material and methods: In this study Bacillus subtilis and Bacillus coagulans, two potential probiotics, were used and grown Bacillus in medium culture containing insoluble calcium phosphate produced nano-hydroxyapatite and nano-calcite. The nano-hydroxyapatite was purified from nano-calcite by heat treatment and washing with a 200 nm filter. The structures, characteristics, and elemental analysis of nano-sized material were studied by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, ultraviolet-visible spectroscopy, energy dispersive X-ray, and X-ray fluorescence. Results: The results showed that hydroxyapatite is made only in a medium containing insoluble calcium phosphate sublimated with urea which is induced phosphatase and urease. Here, for the first time, the braided bacterial nano-hydroxyapatite similar to the bone structure was made in the medium, which caused the production of urease and phosphatase (Maximum 99 U/L) enzymes, and the particle size was less than 100 nm. The ratio of calcium to phosphorus in crude hydroxyapatite and calcite crystal particles made by B. coagulans was 2.9, however, this ratio for pure hydroxyapatite was 1.7. Conclusion: Since the particles are made by antibacterial probiotics, the biological production of these particles makes them a suitable candidate to be used in food, toothpaste, and sanitation products. Braided hydroxyapatite can substitute the needle-like type of food additives for infants and elders due to its safety.

Keywords

• bacillus coagulans
• bacillus subtilis
• calcite
• food additive
• hydroxyapatite
• probiotic