Isolasi Bakteri dan Uji Aktivitas Protease Termofilik dari Sumber Air Panas Sipoholon Tapanuli Utara Sumatera Utara

Abstract

A study on isolation and activity assay of termophilic protease from hot spring of Sipoholon, of North Tapanuli has been done in Laboratory of Microbiology Department of Biology, Faculty of Mathematics and Natural Sciences, University of Sumatera Utara from February to August 2008. This study was aimed to characterize the proteolytic thermophilic bacteria and to know their protease activity. Sixteen isolates showed protease activity in skim milk agars. Three isolates were choosen for further study based on their clearing zone diameter. SP2 showed relatively high hydrolytic activity by 5.96 mm followed by SP1 and SP3 by 5.81 mm and 5.22 mm, respectively. Examination of protease activity was done using Lowry method. The highest crude protease activity was showed by SP3 by 11.6 Unit, with optimum temperature of 65∞C. SP2 showed crude protease activity by 9.93 Unit, with optimum temperature of 65∞C. The lowest crude protease activity showed by SP1 by 9.50 Unit, with temperature of 60∞C. The crude protease was further precipitated with ammonium sulphate at level of 70% saturation. The highest protease activity was showed by SP3 by 12.34 Unit, followed by SP2 and SP1 by 10.92 Unit and 10.59 Unit, respectively.

Isolasi dan uji aktivitas enzim protease termofilik dari sumber air panas Sipoholon Tapanuli Utara telah dilakukan di Laboratorium Mikrobiologi Departemen Biologi, FMIPA USU Medan dari bulan Februari sampai Agustus 2008. Penelitian ini bertujuan untuk memperoleh karakterisasi bakteri termofil proteolitik serta mengetahui aktivitas protease. Enam belas isolat menunjukkan aktivitas protease dalam agar skim milk. Tiga isolat dipilih untuk diuji berdasarkan diameter zona jernih. SP2 menunjukkan aktivitas hidrolitik relatif tinggi sebesar 5.96 mm, yang diikuti oleh SP1 sebesar 5.81 mm dan SP3 sebesar 5.22 mm. Pengujian aktivitas protease dilakukan dengan metode Lowry. Aktivitas protease kasar tertinggi diperoleh pada SP3 sebesar 11.16 Unit, suhu optimum 65∞C. Aktivitas protease kasar SP2 sebesar 9.93 Unit, suhu optimum 65∞C. Aktivitas protease kasar terendah pada SP1 sebesar 9.50 Unit, suhu optimum 60∞C. Protease kasar yang diperoleh dipresipitasi dengan ammonium sulfat pada tingkat kejenuhan 70%. Hasil presipitasi menunjukkan Aktivitas protease tertinggi pada SP3 sebesar 12.34 Unit, yang diikuti oleh SP2 sebesar 10.92 Unit dan SP1 sebesar 10.59 Unit.