Malaysian Journal of Analytical Sciences Vol 18 No 3 (2014): 527 - 533

 

 

 

DETERMINATION OF ENZYME KINETIC PARAMETERS ON SAGO STARCH HYDROLYSIS BY LINEARIZED GRAPHICAL METHODS

 

(Penentuan Enzim Parameter Kinetik pada Hidrolisis Kanji Sagu dengan Kaedah Grafik Lelurus)

 

Long Wee Lai¹*, Chee Loong Teo², Suzana Wahidin³, Mohamad Suffian Mohamad Annuar⁴

 

¹Faculty of  Science and Biotechnology,

 Universiti Selangor, Bestari Jaya 45600, Malaysia

²Faculty of Chemical Engineering,

Universiti Teknologi Malaysia, 81310 UTM Sekudai,  Johor Bahru, Malaysia

³Institute of Chemical and Bioengineering Technology,

 Universiti Kuala Lumpur Malaysia, 78000 Alor Gajah, Melaka, Malaysia

⁴Institute of Biological Sciences,

University of Malaya, 50603 Kuala Lumpur, Malaysia

 

*Corresponding author: zki@unisel.edu.my

 

 

Abstract

Amyloglucosidase (E.C. 3.2.1.3) from Aspergillus niger was used to hydrolyze the sago (Metroxylon sagu) starch into reducing sugars. The experiment was conducted at constant temperature, 55 °C; pH, 4.5 and enzyme amount, 0.2 U/ml, respectively. In this investigation, the substrate concentration was varied ranging from 1.0 – 7.0 g/L. The obtained data were then fixed into linearized plots namely Lineweaver-Burk and Langmuir models to calculate enzyme kinetic parameters, K_m and V_max. Both of the K_m and V_max (mM, mol/min) values from each plot were: Lineweaver-Burk (26.53, 3.31) and Langmuir (13.52, 2.35). Among the linearized models, K_m and V_max values acquired from Langmuir plot was chosen.

 

Keywords: enzyme kinetic parameters, K_m and V_max, Langmuir, Lineweaver-Burk, sago starch hydrolysis

 

Abstrak

Enzim amyloglucosidase (EC 3.2.1.3) dari Apergillus niger digunakan untuk menghidrolisis kanji sagu  (Metroxylon sagu) kepada gula penurun. Eksperimen ini dijalankan pada suhu 55°C; pH, 4.5 dan enzim 0.2U/ml. Kepekatan substrak yang diuji dalam kes ini adalah dalam lingkungan 1.0 – 7.0 g/L. Data yang diperolehi akan digunapakai terus ke dalam linear plot iaitu Lineweaver-Burk serta Langmuir bagi tujuan mengira enzim parameter kinetic:  K_m dan V_max. Kedua-dua nilai K_m dan V_max (mM, mol/min) dari Lineweaver-Burk and Langmuir masing – masing adalah 26.53, 3.31; 13.52, 2.35. Nilai K_m and V_max dari Langmuir model dipilih dalam kajian ini.

 

Kata kunci: enzim parameter kinetik, K_m dan V_max, Langmuir, Lineweaver-Burk, hidrolisis kanji sagu

 

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