Shofiyah Sofi Siti, Yuliani Dewi, Widya Nurul, Sarian Fean D, Puspasari Fernita, Radjasa Ocky Karna, Natalia Dessy
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.
Heliyon. 2020 Dec 26;6(12):e05796. doi: 10.1016/j.heliyon.2020.e05796. eCollection 2020 Dec.
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 NL3 was cloned and expressed in 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. The BmaN2 activity is enhanced strongly by Ca but inhibited by EDTA. BmaN2 also exhibits high catalytic efficiency on soluble starch with value of 14.1 mL mg s. 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.
内陆海湖卡卡班湖具有重要的生态参数，为具有新型生物技术潜力的细菌提供了独特的栖息地，这些细菌使用多种催化剂，包括α-淀粉酶。为了从海洋生物多样性中分离出可降解生淀粉的α-淀粉酶，克隆了海葵相关细菌NL3中编码BmaN2的基因，并在北极快车（DE3）中进行表达。它包含一个1563个核苷酸的开放阅读框，编码520个氨基酸的BmaN2，属于糖苷水解酶家族13亚家族36（GH13_36）。这种α-淀粉酶在pH 6.0和60°C时具有最大活性，比活性为28.7 U mg。BmaN2的活性受到Ca的强烈增强，但受到EDTA的抑制。BmaN2对可溶性淀粉也表现出高催化效率， 值为14.1 mL mg s。尽管没有额外的淀粉结合结构域，但BmaN2能够水解各种生淀粉，如小麦、玉米、木薯、马铃薯、大米、西米和美人蕉，其中颗粒小麦是BmaN2的首选底物。这些特性表明BmaN2是GH13_36亚家族中一种很有前途的可降解生淀粉的酶。
