283 PEMEKATAN ENZIM SELULASE Penicillium sp. LBKURCC20 DENGAN PENGENDAPAN AMONIUM SULFAT 80% JENUH Masdalena Sinaga, Titania T. Nugroho, Andi Dahliaty Mahasiswa Program Studi S1 Kimia Bidang Biokimia Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Kampus Binawidya Pekanbaru, 28293, Indonesia masdalenasinaga@gmail.com ABSTRACT Cellulase enzyme activity of Penicillium sp. LBKURCC20 Isolate of Riau can be increased by concentrating the enzyme using 80% saturated solid ammonium sulfate (NH 4 ) 2 SO 4 anhydrous. Precipitated enzyme was redissolved by the addition of acetate buffer solution pH 5.5 to 1/70 times its original volume. Cellulase enzyme activity was determined using substrates CMC and avicel. CMCase and avicelase enzyme activity of the crude enzyme was (0.0164 ± 0.0036) U/mL and (0.003 ± 0.0025) U/mL, respectively. CMCase and avicelase enzyme activity after concentration was (0.219 ± 0.0579) U/mL and (0.03 ± 0.03) U/mL, respectively. The test results showed that the activity of concentrated CMCase increased 13.5 times and avicelase enzyme activity increased 10 times after concentrating. Keywords: Penicillium sp, cellulase, ammonium sulfate ABSTRAK Enzim selulase Penicillium sp. LBKURCC20 dapat ditingkatkan aktivitasnya dengan pemekatan menggunakan metode penggaraman ammonium sulfat ((NH 4 ) 2 SO 4 ) 80% jenuh. Enzim yang terendapkan dilarutkan kembali dengan penambahan larutan buffer asetat pH 5,5 hingga 1/70 kali volume semula. Aktivitas enzim selulase ditentukan menggunakan substrat CMC dan avisel. Aktivitas ekstrak kasar enzim CMCase dan aviselase masing-masing sebesar (0,0164 ± 0,0036) U/mL dan (0,003 ± 0,0025) U/mL. Aktivitas enzim CMCase dan aviselase setelah pemekatan masing-masing sebesar (0,219 ± 0,0579) U/mL dan (0,03 ± 0,03) U/mL Hasil pengujian menunjukkan aktivitas enzim CMCase pekat meningkat sebesar 13,5 kali dan aktivitas enzim aviselase meningkat sebesar 10 kali setelah pemekatan. Kata kunci: Penicillium sp, selulase, ammonium sulfat.