Adsorption mechanism of immobilization of cyclodextrin glucanotransferase on lemon peel as an effective bio-catalyst /
Eng, Ka Thong,
Adsorption mechanism of immobilization of cyclodextrin glucanotransferase on lemon peel as an effective bio-catalyst / Eng Ka Thong - 75 pages : illustrations ;
Faculty of Chemical and Process Engineering Technology
Final Year Report (Bachelor of Chemical Engineering ) -- Universiti Malaysia Pahang Al-Sultan Abdullah - 2025
Include bibliographical reference
The increasing demand for sustainable and cost-effective biocatalysts has sparked interest in enzyme immobilization on natural, low-cost supports. This study investigates the immobilization of α-CGTase on lemon peel, a waste material abundant in cellulose and hemicellulose, through an adsorption mechanism to enhance enzyme stability and reusability. The objectives were to assess the adsorption kinetics, isotherm models, and thermodynamic behavior of the immobilized enzyme. Lemon peels were processed, and α-CGTase was immobilized under optimized conditions. Adsorption kinetics analysis revealed that the pseudo-first-order kinetic model best describes the adsorption process (R² = 0.9672, k₁ = 0.2153 min⁻¹), suggesting that physisorption governs enzyme attachment. The pseudo-second-order model (R² = 0.9415, k₂ = 0.00428 g/mg·min) and Elovich model (R² = 0.9231, α = 1.21 mg/g·min, β = 0.312 g/mg) also provided good fits, indicating heterogeneous surface interactions. For adsorption isotherms, the Langmuir model demonstrated the best correlation (R² = 0.9583) with a maximum adsorption capacity (qmax) of 49.26 mg/g and an equilibrium constant b = 0.0634 L/mg, confirming monolayer adsorption on a homogeneous surface. The Freundlich isotherm model (R² = 0.9211, Kf = 2.89 mg/g, 1/n = 0.64) suggested surface heterogeneity, while the Temkin model (R² = 0.9025, KT = 0.854 L/mg, B = 4.18 kJ/mol) indicated significant interactions between the enzyme and support material. Thermodynamic analysis confirmed that the adsorption process is spontaneous and exothermic, with negative Gibbs free energy (ΔG = -5.62 kJ/mol at 30°C), negative enthalpy (ΔH = -18.74 kJ/mol), and positive entropy (ΔS = 42.15 J/mol·K). These results indicate that enzyme immobilization on lemon peel occurs naturally and favors energy release. This study underscores the potential of lemon peel as an eco-friendly and cost-effective support material for enzyme immobilization, offering a sustainable solution to waste management challenges while promoting the industrial application of biocatalysis. Future research should focus on optimizing operational conditions, evaluating long-term stability, and scaling up for industrial use. Keywords: α-CGTase; immobilization; lemon peel; adsorption mechanism
THE0010671 (Local)
Faculty of Chemical and Process Engineering Technology--Dissertations
Universities and colleges--Dissertations
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Adsorption mechanism of immobilization of cyclodextrin glucanotransferase on lemon peel as an effective bio-catalyst / Eng Ka Thong - 75 pages : illustrations ;
Faculty of Chemical and Process Engineering Technology
Final Year Report (Bachelor of Chemical Engineering ) -- Universiti Malaysia Pahang Al-Sultan Abdullah - 2025
Include bibliographical reference
The increasing demand for sustainable and cost-effective biocatalysts has sparked interest in enzyme immobilization on natural, low-cost supports. This study investigates the immobilization of α-CGTase on lemon peel, a waste material abundant in cellulose and hemicellulose, through an adsorption mechanism to enhance enzyme stability and reusability. The objectives were to assess the adsorption kinetics, isotherm models, and thermodynamic behavior of the immobilized enzyme. Lemon peels were processed, and α-CGTase was immobilized under optimized conditions. Adsorption kinetics analysis revealed that the pseudo-first-order kinetic model best describes the adsorption process (R² = 0.9672, k₁ = 0.2153 min⁻¹), suggesting that physisorption governs enzyme attachment. The pseudo-second-order model (R² = 0.9415, k₂ = 0.00428 g/mg·min) and Elovich model (R² = 0.9231, α = 1.21 mg/g·min, β = 0.312 g/mg) also provided good fits, indicating heterogeneous surface interactions. For adsorption isotherms, the Langmuir model demonstrated the best correlation (R² = 0.9583) with a maximum adsorption capacity (qmax) of 49.26 mg/g and an equilibrium constant b = 0.0634 L/mg, confirming monolayer adsorption on a homogeneous surface. The Freundlich isotherm model (R² = 0.9211, Kf = 2.89 mg/g, 1/n = 0.64) suggested surface heterogeneity, while the Temkin model (R² = 0.9025, KT = 0.854 L/mg, B = 4.18 kJ/mol) indicated significant interactions between the enzyme and support material. Thermodynamic analysis confirmed that the adsorption process is spontaneous and exothermic, with negative Gibbs free energy (ΔG = -5.62 kJ/mol at 30°C), negative enthalpy (ΔH = -18.74 kJ/mol), and positive entropy (ΔS = 42.15 J/mol·K). These results indicate that enzyme immobilization on lemon peel occurs naturally and favors energy release. This study underscores the potential of lemon peel as an eco-friendly and cost-effective support material for enzyme immobilization, offering a sustainable solution to waste management challenges while promoting the industrial application of biocatalysis. Future research should focus on optimizing operational conditions, evaluating long-term stability, and scaling up for industrial use. Keywords: α-CGTase; immobilization; lemon peel; adsorption mechanism
THE0010671 (Local)
Faculty of Chemical and Process Engineering Technology--Dissertations
Universities and colleges--Dissertations
Theses--Dissertations