AKTIVITAS DAN KARAKTERISASI ENZIM PROTEASE ISOLAT Bacillus sp. (UJ132) SECARA KUALITATIF DAN KUANTITATIF

Abstract

Bakteri penghasil enzim protease memiliki kemampuan untuk melakukan bioremediasi limbah protein. Penelitian ini dilakukan untuk mengetahui aktivitas dan karakterisasi enzim protease dari isolat Bacillus sp. (UJ132) yang diisolasi dari udang pasir (Metapenaeus affinis) di kawasan hutan mangrove Desa Margasari, Lampung Timur. Uji aktivitas enzim dilakukan secara kualitatif dan kuantitatif. Karakterisasi enzim meliputi penentuan suhu dan pH optimum, pengaruh ion logam, serta penentuan Km dan Vmaks. Dari hasil percobaan diketahui bahwa enzim protease dihasilkan pada waktu produksi optimum 18 jam dengan aktivitas protease sebesar 0,09 U/mL. Suhu optimum enzim ini yaitu pada suhu 50°C yang menghasilkan aktivitas sebesar 0,08 U/mL. Enzim protease ini mempunyai kondisi optimum pada pH 5 dengan nilai aktivitas 0,09 U/mL. Semua ion logam (Ca2+, Mn2+, Cu2+, Mg2+) berfungsi sebagai inhibitor kecuali ion Fe3+ yang berfungsi sebagai aktivator pada konsentrasi 1 mM dan 5 mM. EDTA dengan konsentrasi 1 mM dan 5 mM berfungsi sebagai inhibitor pada enzim protease isolat UJ132. Nilai Vmaks enzim protease 0,33 U/mL sedangkan Km senilai 4,59 mg/mL substrat, enzim ini mempunyai afinitas yang tinggi terhadap substrat.

Shrimp farming produces protein wastes which mainly come from the remnants of given feed and excreta (feces) of shrimp. Bacteria known to possess protease enzymes have the ability to solve this protein waste problem in the shrimp farming industry. This study was conducted to determine the production and characterization of protease enzyme from Bacillus sp. (UJ132) isolated from the mangrove forest area of Margasari Village of Lampung Timur. The enzyme activity test was done qualitatively and quantitatively. The objectives of this study were to determine the optimum production of the enzymes and observe their characteristics, including determining the temperature and optimum pH, the effect of several metal ions, as well as Km and Vmax. The experimental results revealed that the protease enzyme had an optimum time of 18 hours of protease activity as much as 0.09 U/mL. The optimum temperature of this enzyme was 50°C which produced an activity of 0.08 U/mL. This protease enzyme has an optimum working condition at pH 5 with an activity value of 0.09 U/mL. All metal ions (Ca2+, Mn2+, Cu2+, Mg2+) acted as inhibitors except Fe3 + ions which acted as activators at concentrations of 1 mM and 5 mM. EDTA with a concentration of 1 mM and 5 mM served as an inhibitor of UJ132 isolate protease enzyme. The value of Vmax of the protease enzyme was 0.33 U/mL while Km was 4.59 mg/mL suggesting that this enzyme has a high affinity with the substrate.