Thermostable amylase activity produced by thermophilic bacteria isolated from Pulu Hotspring, Central Sulawesi

Amylases are important enzymes used in a wide range of industries, such as foods, cosmetics, and pharmaceutics. They are classified based on their mechanism of actions in hydrolyzing starch. Amylases can be isolated from soils, plants, fungi, and bacteria, including thermophilic bacteria. The present study was focused on the determination of best temperature and pH of thermophilic amylase produced by thermophilic bacteria, isolated from Pulu Hotspring. As much as 30 isolates showed amylolytic activity in medium enriched with 1% starch. Of 3 isolates with the highest amylolytic index, PL 16 isolates with amylolytic index of 4.04 mm were studied further to find out its activity in amylose degradation. Enzyme activity was measured with the DNS method using maltose as standard. Temperature and pH measurement were varied in the range of 50, 60, 70, 80, 90, 100°C and 5, 6, 7, 8, 9, respectively. Optimum amylase activity was at a temperature of 90°C and pH 8. These results suggested that thermostable crude amylase from Pulu hotspring has a potential future for industrial application.