CHARACTERIZATION OF RAW STARCH DEGRADING ENZYME ?-AMILASE FROM MARINE BACILLUS SUBTILIS ALSHL3

• Main Author: Vidilaseris, Keni
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/35814
• Institution: Institut Teknologi Bandung

?-Amylases are responsible for hydrolysis of ?-D-(1,4) glycosidic linkages in starch to produce oligosaccharide. These enzymes have been widely used in many industrial fields, such as starch processing, brewing, and bread making. An Indonesian marine isolate identified as B. subtilis ALSHL3 based on 16S rRNA gene produces extracellular ?-amylase. The aim of the research was to characterize raw starch degrading ?-amylase of Indonesia marine isolate, B. subtilis ALSHL3. ?-Amylases of B. subtilis ALSHL3 growth associated with maximum activity occurred at late stationary phase in marine broth medium. ?- Amylases of B. subtilis ALSHL3 have optimum activity at pH 5,0-8,0 and temperature 55-65 oC. Zymograph analysis of the culture supernatant showed that the bacterium secreted at least two types of ?-amylase with molecullar weight of ~150 and ~135 kDa, respectivelly. Rice starch affinity purification of crude enzyme resulted in one band which indicated that the ~150 kDa protein contains starch binding domain. Scanning electron microscope analysis of raw starch treated with the enzyme showed that ?-amylases are capable of degrading rice, cassava, and maize.