Ammonium release in synthetic and human urine by a urease immobilized nanoconstruct

Manab Diasi; Rinki Singh; Amarjyoti Das Mahapatra; Renuka L; Hitarth Patel; Hasit Ganatra; Bhaskar Datta

doi:10.1039/d3ra07606g

Ammonium release in synthetic and human urine by a urease immobilized nanoconstruct

RSC Adv. 2024 Feb 27;14(10):6972-6984. doi: 10.1039/d3ra07606g. eCollection 2024 Feb 21.

Authors

Manab Diasi¹, Rinki Singh¹, Amarjyoti Das Mahapatra¹, Renuka L¹, Hitarth Patel¹, Hasit Ganatra², Bhaskar Datta^{1

3}

Affiliations

¹ Department of Chemistry, Indian Institute of Technology Gandhinagar Palaj Gandhinagar 382355 Gujarat India bdatta@iitgn.ac.in rinkoosingh62@gmail.com.
² Blasto Research Private Limited Ahmedabad Gujarat India.
³ Department of Biological Engineering, Indian Institute of Technology Gandhinagar Palaj Gandhinagar 382355 Gujarat India.

Abstract

In this work, we have studied the ability of urease immobilized on glutaraldehyde crosslinked chitosan coated magnetic iron oxide nanoparticles (Urease/GA/CS/MIONPs), for the hitherto unreported comparative hydrolysis of urea in synthetic (SUr) and real human urine (HUr). The prepared Urease/GA/CS/MIONPs were characterized by a combination of Fourier transform infrared spectroscopy (FTIR), field emission-scanning-electron-microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and dynamic light scattering (DLS). The nanoconstructs display the highest ammonium ion liberation post-urea hydrolysis in 1/20 or 1/24-fold dilutions of SUr and HUr, respectively. The optimum activity of immobilized urease is observed at pH 7, and the nanoconstructs facilitate efficient urea-hydrolysis till at least 45 °C. Kinetic analysis of the immobilized urease shows k_m and v_max of 14.81 mM, 12.36 mM, and 18.55 μM min^-1 and 10.10 μM min^-1, towards SUr and HUr, respectively. The magnetization of the immobilized urease is suitable for reuse across multiple cycles of urea hydrolysis in SUr and HUr. The robust performance of Urease/GA/CS/MIONPs in SUr and HUr is promising for generating ammonium as a useable source of nitrogen from human urine, and underscores the suitability of SUr as a urine mimic for such interventions.