Optimasi Produksi Keratinase Oleh Bakteri Bacillus Slii-I Dalam Medium Limbah Bulu Ayam

Keratin adalah protein yang sulit didegradasi karena terdapat ikatan sistin disulfida. Enzim keratinase yang diproduksi oleh Bacillus SLII-I diketahui mampu memutus ikatan disulfida. Tujuan dari penelitian ini adalah untuk memproduksi keratinase secara optimum melalui analisis profil kurva pertumbuhan bakteri, kandungan protein, dan aktivitas keratinase dengan memvariasikan kondisi pH dan komposisi medium limbah bulu ayam. Optimasi keratinase dilakukan berdasarkan kurva pertumbuhan bakteri yang dikulturkan pada 3 jenis medium (Nutrien broth, minimal medium feather meal, minimal medium feather meal pepton 1%) dan 3 jenis pH (7, 8, 9). Analisis optimasi diperoleh dari profil kurva pertumbuhan serta karakterisasi menggunakan titik isoelektrik, dan SDS-PAGE yg didahului dengan parsial purifikasi menggunakan ammonium sulfat. Dari hasil diperoleh produksi keratinase yang optimum pada minimal medium feather meal pH 7 dengan aktifitas keratinase tertinggi adalah 3.4 Unit/ml. Titik isoelektrik keratinase diketahui pada pH 5.3 sedangkan berat molekul berdasarkan hasil SDS-PAGE adalah 38 kDa. =============================================================================================== Keratin is a protein that is difficult to degrade because there is cystine disulfide bond. Keratinase enzyme produced by Bacillus SLII-I is known to break the disulfide bonds. The purpose of this research is to produce optimum keratinase through bacterial growth profile analysis, protein content, and keratinase activity by varying conditions of pH and composition of medium feather meal. Keratinase optimization performed by the growth curve of bacteria cultured in three types of medium (Nutrien broth, minimal medium feather meal, and minimal medium feather meal pepton 1%) and three types of pH (7, 8, and 9). Optimization analysis is obtained from the profile curve of growth, characterization using isoelectric point, and SDS-PAGE which was preceded by a partial purification using ammonium sulfate. The results obtained optimum keratinase production in minimal medium feather meal pH 7 with the highest keratinase activity is 3.4 Units / ml. Keratinase known isoelectric point at pH 5.3 and the molecular weight by SDS-PAGE results is 38 kDa