title: Microbial mineralization of struvite: a promising process to overcome phosphate sequestering crisis.
abstract: Due to extensive exploitation of non-renewable phosphate minerals, their natural reserves will exhaust very soon. This necessitates looking for alternatives and an efficient methodology through which indispensable phosphorus can be harvested back. The current study was undertaken to explore the potential of a metallophilic bacterium Enterobacter sp. EMB19 for the recovery of phosphorus as phosphate rich mineral. A very low phosphate concentration strategy was adopted. The process led to the mineralization of phosphorus as homogeneous struvite crystals. For each gram of Epsom salt added, the cells effectively mineralized about 20% of the salt into struvite. The effect of different inorganic sources, culture profile and plausible mechanism involved in crystal formation was also explored. The synthesized struvite crystals typically possessed a prismatic crystal habit. The characterization and identification of the crystals were done using single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), energy dispersive X-ray analysis (EDAX) and fourier transform infrared (FTIR). The thermal characteristics were studied using thermo gravimetric analysis (TGA) and differential scanning calorimetric (DSC) processes. The synthesis of struvite by this bacterium seems to be a promising and viable strategy since it serves dual purpose (i) obtaining phosphorus and nitrogen rich fertilizer and (ii) conservation of natural phosphate reserves. This study is very significant in the sense that the process may be used for harvesting and synthesizing other valuable minerals. Also, it will provide new insights into phosphate biomineralization mechanisms.
authors: Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
authors: Arvind
authors: A
authors: Sinha
authors: Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
authors: Amit
authors: A
authors: Singh
authors: Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
authors: Sumit
authors: S
authors: Kumar
authors: Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India. Electronic address: skhare@rocketmail.com.
authors: Sunil Kumar
authors: SK
authors: Khare
authors: Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
authors: Arunachalam
authors: A
authors: Ramanan
mesh_terms: D003460:Crystallization; D004754:Enterobacter / Q000254:growth & development / Q000378:metabolism*; D017616:Magnesium Compounds / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D011208:Powders; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D000069877:Struvite; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D017616:Magnesium Compounds; D008903:Minerals; D010710:Phosphates; D011208:Powders; D000069877:Struvite
keywords: Biomineralization; Enterobacter; Phosphate; Single crystal; Struvite