PEMURNIAN SELULOSA-α HASIL HIDROLISIS PELEPAH SAWIT MENGGUNAKAN ENZIM XYLANASE DENGAN VARIASI pH DAN SUMBER ENZIM XYLANASE Sari, D. P*, Padil**; Yelmida** *Alumni Teknik Kimia Universitas Riau **Jurusan Teknik Kimia, Fakultas Teknik, Universitas Riau Kampus Binawidya Km 12,5 Simpang Baru Panam, Pekanbaru 28293 diyt_1712@yahoo.com Abstract Midrib palm is one of the waste that produced from palm farming which contain alpha cellulose about 35%. The component of alpha cellulose could be used as a raw material for nitrocellulose if it is has more than 92% of purity. So to increase the purity of alpha cellulose, midrib palm has to be treated by purifying step. In this time, chemical still be choices to be material for purify alpha cellulose, while as we know that chemical has a bad impact for our envirotment. So it is important to search another purifying agent and it is xylanase. Xylanase is one of enzyme that has an ability to break up the link between xylose in xylan. So the purpose of this research are to use xylanase as another purifying agent, to know what is the best pH for this purifying process and to compare the result between two xylanases that produced from different fungi. Before start the purifying step, midrib have to through extraction step to remove all extractive and continue with hydrolisis step by using extraction liquid of palm empty bunch ash. Then after that purifying step can be done at 60 0 C for 1,5 hours by making some differences at pH (4,5 and 6). The highest purity of alpha cellulose was reached at pH 6 by using xylanase from Aspergillus niger about 97,55%. So the conclucion of this research are, the best pH for purifying process by using xylanase is 6 and the best xylanase is the one which produce from Aspergillus niger. Beside that, the use of xylanase which is comes from the same species will be not affected much to the purifying result. Keyword : hydrolisis, midrib palm, xylanase enzyme. 1. Pendahuluan Perkembangan industri sawit di Indonesia, khususnya Provinsi Riau tidak lepas dari sisa produksi dan limbah. Limbah industri pengolahan sawit dapat berupa limbah kimia maupun limbah pertanian. Pelepah sawit merupakan salah satu limbah pertanian yang dihasilkan pada saat panen buah sawit. Dari perkebunan sawit, dalam satu tahun akan dihasilkan 6,3 ton pelepah sawit per hektar (Litbang Deptan, 2010). Pemanfaatan limbah pelepah sawit belum dilakukan secara optimal. Sejauh ini pelepah sawit masih diolah sebatas menjadi pakan ternak dan pupuk kompos, bahkan sebagian besar petani menumpuk pelepah sawit begitu saja di perkebunan. padahal analisa kimia terhadap pelepah sawit menyatakan bahwa terdapat komponen selulosa, hemiselulosa, dan lignin yang masih dapat dimanfaatkan menjadi produk yang bernilai lebih ekonomis. Padil (2010) melaporkan komposisi selulosa, hemiselulosa, dan lignin pelepah sawit secara berturut-turut adalah ; 34,89%, 27,14%, dan 19,87%. Komponen selulosa dalam pelepah sawit dapat ditingkatkan kemurniannya dengan cara menghidrolisis pelepah sehingga didapatkan selulosa yang lebih murni. Namun pada proses hidrolisis, tidak seluruh bagian selulosa dapat terpecah dari