Jurnal Kejuruteraan 30(2) 2018: 187-192 http://dx.doi.org/10.17576/jkukm-2018-30(2) Optimising Cutinase Enzyme Recovery in Thermo-Induced Phase Separation of LS54/ DX ATPS by Enhanced Volume Exclusion Effect (Pengoptimuman Perolehan Enzim Kutinase pada Fasa Pemisahan Teraruh-suhu S2FA LS54/DX dengan Meningkatkan Kesan Penyingkiran Isipadu) Fariza Akmal Abdul Mutalib Department of Chemical and Process Engineering, Faculty of Engineering & Built Environment Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia Jamaliah Md Jahim* Department of Chemical and Process Engineering, Faculty of Engineering & Built Environment Research Centre for Sustainable Process Technology, Faculty of Engineering & Built Environment Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia Abdul Wahab Mohammad Department of Chemical and Process Engineering, Faculty of Engineering & Built Environment Research Centre for Sustainable Process Technology, Faculty of Engineering & Built Environment Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia Qatar Energy and Environment Research Instititue, Hamad bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar Farah Diba Abu Bakar Centre of Bioscience & Biotechnology Studies, Faculty of Science & Technology Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia ABSTRACT Low recovery of cutinase enzyme in water-enriched phase after thermo-induced separation stage of LS54/Dx aqueous two- phase system was improved by enhanced volume exclusion effect in the polymer-water extraction system. It was done by increased the polymer concentration in the polymer-water system. After primary phase separation, more LS54 (polymer) which is the system’s component itself were added into polymer-enriched phase and mixed thoroughly before thermo-induced separation step proceeded. The compositions of LS54 added into the polymer-enriched phase were 0.25, 0.5 and 0.75 g LS54/g top phase. The thermo-induced phase separation was carried out at 37°C. It was found that cutinase recovery in water-enriched phase was increased up to 5-13% with the increment of polymer concentration in the system as compared to a system without polymer addition. The optimum concentration obtained for the polymer added was 0.5 g LS54/g top phase whereby it attained 82% recovery of cutinase enzyme in water-enriched phase after thermoseparation step. Although the increment of enzyme recovery was not exceptionally high as compared to another method such as adding ligand, an affnity tag or neutral salt, still this method is applicable because of its more straightforward work, polymer recycle capability, and enzyme recovery in water phase would defnitely give beneft to further downstream processing. Keywords: Aqueous two phase system (ATPS); thermoseparation; enzyme recovery; volume-exclusion effect ABSTRAK Perolehan rendah enzim cutinase dalam fasa diperkaya air selepas peringkat pemisahan teraruh suhu sistem dua fasa berakueus LS54/Dx ditambahbaik dengan meningkatkan kesan penyingkiran isipadu dalam sistem pengekstrakan polimer- air. Ia dilakukan dengan meningkatkan kepekatan polimer dalam sistem pengekstrakan tersebut. Selepas pemisahan fasa utama, lebih banyak LS54 (polimer) iaitu komponen sistem ini sendiri, telah ditambah ke dalam fasa diperkaya polimer dan dicampur dengan baik sebelum langkah pemisahan teraruh suhu diteruskan. Komposisi LS54 yang ditambahkan ke dalam fasa diperkaya polimer adalah 0.25, 0.5 dan 0.75 g LS54/g fasa atas. Pemisahan fasa teraruh suhu dilakukan pada 37°C. Didapati perolehan cutinase dalam fasa diperkaya air meningkat sehingga 5-13% dengan peningkatan kepekatan polimer dalam sistem berbanding dengan sistem tanpa penambahan polimer. Kepekatan optimum yang diperolehi bagi penambahan polimer ialah 0.5 g LS54/g fasa atas di mana ia mencapai 82% perolehan enzim kutinase dalam fasa diperkaya air selepas langkah pemisahan teraruh suhu. Walaupun peningkatan perolehan enzim tidak begitu tinggi berbanding dengan kaedah lain seperti penambahan ligan, tag affnity atau garam neutral, namun kaedah ini boleh diguna pakai kerana kerjanya yang lebih mudah, berkeupayaan kitar semula polimer, dan perolehan enzim dalam fasa air pasti memberi manfaat untuk pemprosesan hiliran seterusnya. Kata kunci: Sistem Dua Fasa Berakueus (S2FA); pemisahan teraruh suhu; perolehan enzim; kesan penyingkiran isipadu Artikel 8.indd 187 10/10/2018 11:20:49