TY  - JOUR
AU  - Nurachman, Zeily 
AU  - Kono, Alfredo 
AU  - Radjasa, Ocky Karna 
AU  - Natalia, Dessy 
PY  - 2010
TI  - Identification a Novel Raw-Starch-Degrading-α-Amylase from a Tropical Marine Bacterium
JF  - American Journal of Biochemistry and Biotechnology
VL  - 6
IS  - 4
DO  - 10.3844/ajbbsp.2010.300.306
UR  - https://thescipub.com/abstract/ajbbsp.2010.300.306
AB  - Problem statement: Bacteria from the surface of the tropical marine hard coral Acropora sp. were screened for producing raw-starch-degrading-α-amylase. Approach: Based on its 16s rDNA sequence, a bacterium that produced the highest amylolitic activity was identified as Bacillus amyloliquifaciens ABBD. The bacterial isolate secreted a α-amylase extracellularly and then the enzyme was partially purified by ammonium sulfate precipitation followed by anion exchange chromatography. Results: Electrophoresis results both SDS-PAGE and native PAGE suggested that the enzyme was a heterodimeric protein (97 kDa) consisting of 45 and 55 kDa subunits. The α-amylase had an optimum pH of 7.0 and temperature of 60°C. More than 80% activity of the enzyme was retained under high salt conditions (up to 20% NaCl). The enzyme remained stable at 50°C for 1 h. Starch hydrolysis by the enzyme at 70°C yielded oligosaccharides (G2-G4) and at room temperature yielded glucose/maltose (G1 and G2). Conclusion: The B. amyloliquifaciens ABBD α-amylase was capable of degrading various raw starch granules from corn, rice, cassava and sago at room temperature.