Purification and characterization of thermostable alpha‐amylase from Geobacillus sp. DS3 from Sikidang Crater, Central Java, Indonesia

Amylases are considered the most essential enzymes in biotechnology since they widely utilized textile, food processing, and detergent industries. It is necessary to explore extracellular enzymatic activity several microorganisms discover a new potential application from amylases. In previous study, thermophilic bacteria Geobacillus sp. DS3 isolated Sikidang Crater, Dieng Plateau, Central Java, Indonesia showed amylase starch medium at 70 °C. This study aimed purify characterize thermostable alpha‐amylase DS3. The was produced purified using ammonium sulfate DEAE Sephadex A‐25 column. enzyme determined 3,5‐dinitrosalicylic acid (DNS) method. optimally 60 °C for 15 h. exhibited high 40–60% saturated extract. molecular weight of estimated be 58 kDa. optimum temperature 50 200 mM sodium phosphate buffer pH 7.0. inhibited by EDTA, PMSF, 2‐ME, mostly HgCl2. Km Vmax pure were 235.43 1428.57 U/mL, respectively. result suggested that offers areas industry, such as bakery industry.