Enzymatic detection of As(III) in aqueous solution using alginate immobilized pumpkin urease: Optimization of process variables by response surface methodology

• Published in: Bioresource technology 2009-10, Vol.100 (19), p.4462-4467
• Main Authors: Talat, Mahe, Prakash, Om, Hasan, S.H.
• Format: Article
• Language: English
• Subjects: agricultural wastes; alginates; Alginates - chemistry; Analysis of Variance; aqueous solutions; arsenic; Arsenic - analysis; As 3; Biological and medical sciences; chemical analysis; Cucurbita - enzymology; Environmental Restoration and Remediation - methods; enzymatic hydrolysis; enzyme activity; Enzymes, Immobilized - metabolism; Fundamental and applied biological sciences. Psychology; Glucuronic Acid - chemistry; groundwater; Hexuronic Acids - chemistry; Immobilized; immobilized enzymes; Inhibition; Ions; plant residues; pollutants; pumpkins; quantitative analysis; Regression Analysis; Response surface methodology; seeds; Solubility; Solutions; Substrate Specificity; Surface Properties; Time Factors; toxic substances; urea; Urease; Urease - metabolism; Water - chemistry; water pollution
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2009.04.009

Urease immobilized on alginate was utilized to detect and quantify As 3+ in aqueous solution. Urease from the seeds of pumpkin (vegetable waste) was purified to apparent homogeneity by heat treatment and gel filtration (Sephadex G-200). Further enzyme was entrapped in 3.5% alginate beads. Urea hydrolysis by enzyme revealed a clear dependence on the concentration and interaction time of As 3+. The process variables effecting the quantitation of As 3+ was investigated using central composite design with Minitab ® 15 software. The predicted results were found in good agreement ( R 2 = 96.71%) with experimental results indicating the applicability of proposed model. The multiple regression analysis and ANOVA showed that enzyme activity decreased with increase of As 3+ concentration and interaction time. 3D plot and contour plot between As 3+ concentration and interaction time was helpful to predict residual activity of enzyme for a particular As 3+ at a particular time.