Production Optimization and Characterization of Amylase Enzyme Isolated from Termofil Bacteria Bacillus sp RSAII-1b from Lejja Hot Spring South Sulawesi

摘要

Thermostable amylase enzyme has a broad commercial value in its use in the processing of starch, sugar production, textile, paper, animal feed, pharmaceuticals and in the manufacture of detergents. This study aims to determine the optimum conditions of amylase production from the termofil bacteria Bacillus sp. RSII-1b isolated from a hot spring Lejja South Sulawesi and characterizing the amylase enzyme. The testing of amylase production was done with various concentration of starch and CaCl_2 in the production medium, then fermented to obtain maximum amylase activity, amylase enzyme was produced in optimum condition, and its characteristic was tested using 2% starch substrates in various pH, temperature and determining the compound cofactor which can act as activators or inhibitors of the amylase activity, the enzyme activity was tested using DNS method. Crude extract enzyme has the highest enzyme activity of the protein content determined by the method of Lawry. The results showed that the amylase enzyme from Bacillus sp RSAII-1b isolates can be manufactured to a maximum at 33 hours of fermentation time with conditions: the concentration of substrate (starch) 1.5%, 0.08% CaCl2, 55℃ temperature, medium pH 7.0 and aeration speed 200rpm with the activity of 0.1323U/mL, amylase crude extract protein content of 1.86mg/mL, with spesifik activity 0.0711 U/mg protein. Crude extract amylase work optimally at pH 6.0; 55℃ -60℃ the amylase activity of 0.165U/mL, the specific activity of 0.089U/mg protein. Amylase enzyme is an enzyme that depends on metal because its catalytic activity can be activated by metal ions Ca~(2+), Mg~(2+), Cu~(2+), Ni~(2+) and Co~(2+) as activators whereas Zn~(2+) ions decrease the activity of enzymes as inhibitors. Amylase activity in the crude extract optimum conditions with the addition of 10 mm ions Ca~(2+) can increase amylase activity up to 32,89%, while the addition of ions Zn2+ can inhibit amylase activity up to 25%.