Identification a Novel Raw-Starch-Degrading-α-Amylase from a Tropical Marine Bacterium

Abstract

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.

Halotolerant, acid‐alkali stable, chelator resistant and raw starch digesting α‐amylase from a marine bacterium Bacillus subtilis S8–18

“…This has generated in recent years, the emergence of intensive research on identification of amylases with the potential to hydrolyze directly the raw starch substrates in a single step without the need of gelatinization which involves high cost [7,8]. While majority of existing records deal with raw starch digesting a-amylases from soil isolates [6][7][8][9] and only very few reports engage the marine enzyme [10,11], the present investigation identified a potential raw starch digesting enzyme from a marine sediment isolate Bacillus subtilis S8-18, which acts optimum at liquefaction temperature (60°C).…”

Isolasi dan Karakterisasi Amilase dari Biji Durian (Durio sp.)

“…Absorbansinya diukur pada panjang gelombang 600 nm. [5] Konsentrasi amilase diuji dengan metode Bradford. Sebanyak 500 µL ekstrak enzim dan 500 µL pereaksi Bradford divortex, diinkubasi selama 5-10 menit pada suhu ruang.…”

“…Absorbansinya diukur pada panjang gelombang 600 nm. [5] Suhu Optimum Sebanyak 50 µL larutan pati 3% dalam buffer fosfat 50 mM pH 7,5, ditambah 50 µL larutan enzim dan diinkubasi pada suhu (30, 40, 50, 60, dan 70 ºC) selama 10 menit. Campuran ditambah 50 µL HCl 1 M, 50µL larutan iodium (mengandung 2% KI dan 0,2% I2) dan diencerkan dengan akuades hingga volume 1 mL.…”

Microwave Assisted Alkaline Pretreatment and Microwave Assisted Enzymatic Hydrolysis of Palm Oil Mill Effluent (POME) for Optimum Fermentable Sugar Yield

“…Specific enzymes such as amylase, amyloglucoamylase and pulluanase are needed for hydrolyzing starch 25,26 . Tapai is a traditional fermented food popular in Malaysia and Indonesia.…”