Highly multilayered urease decomposes highly concentrated urea.

Area of Science:

• Biocatalysis
• Membrane Science
• Biotechnology

Background:

• Urea hydrolysis is crucial for various applications, including wastewater treatment and ammonia production.
• Immobilization of enzymes like urease enhances their stability and reusability.
• Developing efficient methods for urea hydrolysis is essential for managing urea-rich solutions.

Purpose of the Study:

• To develop a highly efficient immobilized urease system for urea hydrolysis.
• To investigate the performance of urease immobilized on a porous hollow-fiber membrane.
• To assess the urea hydrolysis capability under varying concentrations and permeation rates.

Main Methods:

• Urease immobilization via ion-exchange binding and cross-linking with transglutaminase onto a modified hollow-fiber membrane.
• Permeation of urea solutions (2-8 M) through the immobilized membrane.
• Analysis of urea hydrolysis efficiency at different permeation rates and residence times.

Main Results:

• Achieved high-density urease immobilization (1.2 g urease/g matrix) on the membrane.
• Demonstrated quantitative hydrolysis of 4 M urea at a low permeation rate (<1 mL/h) and ambient temperature.
• Observed urease denaturation at urea concentrations exceeding 6 M.

Conclusions:

• The developed immobilized urease membrane exhibits efficient convective transport and hydrolysis of urea.
• The system shows promise for applications requiring high-efficiency urea breakdown.
• Further research is needed to address urease stability at very high urea concentrations.