Isolation, expression, and characterization of raw starch degrading α-amylase from a marine lake Bacillus megaterium NL3
Sofi Siti Shofiyah,
Dewi Yuliani,
Nurul Widya,
Fean D. Sarian,
Fernita Puspasari,
Ocky Karna Radjasa,
Ihsanawati,
Dessy Natalia
Affiliations
Sofi Siti Shofiyah
Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia; Marine Science Program Study, Faculty of Marine Science, OSO University, Pontianak, 78113, Indonesia
Dewi Yuliani
Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia
Nurul Widya
Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia
Fean D. Sarian
Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia
Fernita Puspasari
Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia
Ocky Karna Radjasa
Center for Tropical Coastal and Marine Studies, Diponegoro University, Widya Puraya, Semarang, 50275, Indonesia; Indonesian Institute of Sciences, Gatot Subroto 10, Jakarta, Indonesia
Ihsanawati
Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia
Dessy Natalia
Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia; University Center of Excellence for Nutraceuticals, Biosciences and Biotechnology Research Center, Bandung, Indonesia; Corresponding author.
A land-locked marine lake Kakaban with its significant ecological paramaters provides a unique habitat for bacteria with novel biotechnology potential that uses a diverse array of catalytic agents, including α-amylase. Aiming at the isolation of raw starch degrading α-amylase from marine biodiversity, a gene encoding BmaN2 from a sea anemone associated bacterium Bacillus megaterium NL3 was cloned and expressed in Escherichia coli ArcticExpress (DE3). It comprises an open reading frame of 1,563 nucleotides encoding BmaN2 of 520 amino acids and belongs to the glycoside hydrolase family 13 subfamily 36 (GH13_36). This α-amylase has a maximum activity at pH 6.0 and 60 °C with a specific activity of 28.7 U mg−1. The BmaN2 activity is enhanced strongly by Ca2+ but inhibited by EDTA. BmaN2 also exhibits high catalytic efficiency on soluble starch with kcat/KM value of 14.1 mL mg−1 s−1. Despite no additional starch-binding domain, BmaN2 is able to hydrolyze various raw starches, such as wheat, corn, cassava, potato, rice, sago, and canna, in which granular wheat is the preferred substrate for BmaN2. These characteristics indicate that BmaN2 is a promising raw starch degrading enzyme within the subfamily GH13_36.
