title: Optimized preparation and characterization of CLEA-lipase from cocoa pod husk.
abstract: Cross-linked enzyme aggregate (CLEA) is easily prepared from crude enzyme and has many advantages to the environment and it is considered as an economic method in the context of industrial biocatalysis compared to free enzyme. In this work, a highly active and stable CLEA-lipase from cocoa pod husk (CPH) which is a by-product after removal of cocoa beans, were assayed for their hydrolytic activity and characterized under the optimum condition successfully. Face centered central composite design (FCCCD) under response surface methodology (RSM) was used to get the optimal conditions of the three significant factors (concentration of ammonium sulfate, concentration of glutaraldehyde and concentration of additive) to achieve higher enzyme activity of CLEA. From 20 runs, the highest activity recorded was around 9.407U (83% recovered activity) under the condition of using 20% saturated ammonium sulfate, 60mM glutaraldehyde as cross-linker and 0.17mM bovine serum albumin as feeder. Moreover, the optimal reaction temperature and pH value in enzymatic reaction for both crude enzyme and immobilized were found to be 45°C at pH 8 and 60°C at pH 8.2, respectively. A systematic study of the stability of CLEA and crude enzyme was taken with regards to temperature (25-60°C) and pH (5-10) value and in both factors, CLEA-lipase showed more stability than free lipase. The Km value of CLEA was higher compared to free enzyme (0.55mM vs. 0.08mM). The CLEA retained more than 60% of the initial activity after six cycles of reuse compared to free enzyme. The high stability and recyclability of CLEA-lipase from CPH make it efficient for different industrial applications.
authors.affiliation: Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, PO Box 10, 50728 Kuala Lumpur, Malaysia. Electronic address: Sophia.khan.ahmadi@gmail.com.
authors.forename: Soofia
authors.initials: S
authors.lastname: Khanahmadi
authors.affiliation: Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, PO Box 10, 50728 Kuala Lumpur, Malaysia.
authors.forename: Faridah
authors.initials: F
authors.lastname: Yusof
authors.affiliation: Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, PO Box 10, 50728 Kuala Lumpur, Malaysia.
authors.forename: Azura
authors.initials: A
authors.lastname: Amid
authors.affiliation: Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, PO Box 10, 50728 Kuala Lumpur, Malaysia.
authors.forename: Safa Senan
authors.initials: SS
authors.lastname: Mahmod
authors.affiliation: Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, PO Box 10, 50728 Kuala Lumpur, Malaysia.
authors.forename: Mohd Khairizal
authors.initials: MK
authors.lastname: Mahat
mesh_terms: D000645:Ammonium Sulfate / Q000737:chemistry; D055162:Biocatalysis; D002099:Cacao / Q000201:enzymology*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D013696:Temperature
chemical_list: D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D010940:Plant Proteins; D008049:Lipase; D000645:Ammonium Sulfate; D005976:Glutaral
keywords: CLEA-lipase; Cocoa pod husk; Face centered central composite design; Response surface methodology