CHARACTERIZATION OF RAW STARCH DEGRADING ALPHA-AMYLASES OF MARINE BACILLUS SUBTILIS ALSHL3

• Main Author: Vidilaseris (NIM 105 03 010), Keni
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/6355
• Institution: Institut Teknologi Bandung

ABSTRACT: <br /> <br /> <br /> Alpha-Amylases are responsible for hydrolysis of alpha-D-(1,4) glycosidic linkages in starch to produce oligosaccharide and small quantities of glucose. 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 alpha-amylase. The aim of the research was to characterize raw starch degrading alpha-amylases of B. subtilis ALSHL3. alpha-Amylases of B. subtilis ALSHL3 secretion was growth associated with maximum activity occurred at late stationary phase. alpha-Amylases of B. subtilis ALSHL3 work at pH range of 5,0-8,0 and temperature range of 55-65 oC. Zymograph analysis of the culture supernatant showed that the bacterium secreted at least two types of alpha-amylase with molecullar weight of ~150 and ~135 kDa, respectively. Rice starch affinity purification of alpha-amylases 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 enzymes showed that the alpha-amylases are capable of degrading rice, cassava, and maize.