Characterization Of The Depolymerizing Activity Of Commercial Lipases And Animal Organ Extracts Using A Simple Polyhydroxyalkanoate-Based Microassay

• Main Author: Mok, Pei Shze
• Format: Thesis
• Language: English
• Published: 2015
• Subjects: QH1-278.5 Natural history (General)
• Online Access: http://eprints.usm.my/31939/

Lipase ialah enzim yang digunakan dalam pelbagai aplikasi dan aktivitinya perlu diuji sebelum aplikasi. Namun begitu, kebanyakkan asai aktiviti lipase memerlukan bahan kimia toksik dan persediaan yang rumit. Oleh itu, poli(3-hidroksibutirat-ko-4-hidroksibutirat) [P(3HB-ko-4HB)] digunakan sebagai substrat pepejal kerana ia dapat diuraikan oleh lipase. Substrat ini boleh diuraikan secara semula jadi dan tidak memerlukan bahan kimia yang bertoksik. Dalam kajian ini, 2.0 ± 0 g/L sel mengandungi 28 ± 2 % of PHA dengan 92 ± 1 mol % of 4HB dalam PHA telah dibiosintesis. Kestabilan filem P(3HB-ko-4HB) dinilai dengan menyimpan filem tersebut di bawah keadaan yang berbeza iaitu di ketuhar vakum, balang pengering dan meja makmal selama 15 bulan. Filem tersebut paling stabil dalam balang pengering yang mengandungi gel silika. Aktiviti depolimerasi lipase komersial dan ekstrak organ haiwan telah diuji secara mikroasai dengan menggunakan P(3HB-ko-4HB) sebagai substrat. Lipase is an enzyme that is widely used in different applications and it is important to screen its activity before application. However, most of the available lipase activity assays require toxic chemicals and tedious preparation. Therefore, a solid substrate known as poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] is used and it can be degraded by lipases. This substrate is biodegradable and does not require toxic chemical. In this study, 2.0 ± 0 g/L of cells consisting 28 ± 2 % of PHA with 92 ± 1 mol % of 4HB were produced through biosynthesis. The stability of P(3HB-co-4HB) films was evaluated by storing them in different locations, in vacuum oven, desiccators and bench for 15 months. The film was found to be the most stable in desiccators containing silica gel. The depolymerizing activity of different known commercial lipases and animal organ extracts using P(3HB-co-92 mol% 4HB) as substrate was investigated via microassay.