Optimasi pH, Suhu, dan Ion Logam Terhadap Aktivitas Fitase Aspergillus niger IPBCC 93 0265

Abstract

Fitase merupakan enzim penting yang berperan dalam menghidrolisis asam fitat, sehingga pemahaman terhadap karakteristik aktivitasnya menjadi hal yang krusial. Penelitian ini berfokus pada penentuan pengaruh pH, suhu, dan ion logam terhadap aktivitas fitase yang dihasilkan oleh Aspergillus niger IPBCC 93 0265. Enzim diproduksi melalui fermentasi cair, kemudian dimurnikan secara parsial menggunakan metode fraksinasi amonium sulfat dan dialisis. Aktivitas fitase dianalisis pada variasi pH, suhu, serta penambahan beberapa ion logam dan EDTA pada konsentrasi 2 mM dan 5 mM. Hasil penelitian menunjukkan bahwa fraksi protein 30–80% memiliki aktivitas spesifik tertinggi sebesar 3,4 U/mg. Aktivitas optimum fitase diperoleh pada pH 5 dan suhu 60 °C dengan bobot molekul sekitar 55 kDa. Penambahan ion logam secara umum meningkatkan aktivitas fitase, sedangkan EDTA menunjukkan peningkatan aktivitas yang lebih rendah.

Phytase is an important enzyme that plays a role in the hydrolysis of phytic acid; therefore, understanding its activity characteristics is essential. This study focused on determining the effects of pH, temperature, and metal ions on the activity of phytase produced by Aspergillus niger IPBCC 93 0265. The enzyme was produced through submerged fermentation and partially purified using ammonium sulfate fractionation and dialysis. The enzyme was partially purified using ammonium sulfate fractionation followed by dialysis. Phytase activity was analyzed under various pH and temperature conditions and in the presence of several metal ions and EDTA at concentrations of 2 mM and 5 mM. The results showed that the 30–80% protein fraction exhibited the highest specific activity of 3.4 U/mg. The optimum phytase activity was observed at pH 5 and a temperature of 60 °C, with a molecular weight of approximately 55 kDa. The addition of metal ions generally increased enzyme activity, whereas EDTA resulted in a lower increase in activity.