Powdered Enzyme from Australian Weed for Bio-stabilisation

The urease enzyme derived from Paddy melon (Australian weed) seeds, is highly effective in catalyzing the hydrolysis of urea in the presence of calcium ions. This reaction results in the precipitation of calcium carbonate, which then binds/cements soil particles. This process is known as the Enzyme-Induced Carbonate Precipitation method (EICP). Recently, EICP has been utilized in geotechnical engineering to enhance various physical properties of soil, such as strength, hydraulic conductivity, and reactivity. However, crude enzyme solution is easily degraded with time, even at low temperatures, making it challenging to produce and store for larger-scale applications. Therefore, this study aims to transform the liquid enzyme solution into a powdered enzyme using the freeze-drying technique (lyophilization) to avoid degradation problems. The catalytic activity of the enzyme powder from Paddy melon was measured at 2.867 KU/g, which is equivalent to commercially available purified enzymes. In addition, cost analysis suggested that the powderisation process can help produce the enzyme powder at a lower cost than commercial products, enhancing the affordability of the EICP application in soil stabilization.