Overexpression and Characterization of a Novel Thermostable β-Agarase YM01-3, from Marine Bacterium Catenovulum agarivorans YM01T

Marine Drugs

Fangyuan Cui²  Sujie Dong²  Xiaochong Shi²  Xia Zhao¹ 

[1] School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China; E-Mail:;College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; E-Mails:

关键词: Catenovulum agarivorans YM01^T;    expression;    characterization;    YM01-3;    β-agarase;    thermostable;   

DOI  :  10.3390/md12052731

来源: mdpi

【 摘 要 】

Genome sequencing of Catenovulum agarivorans YM01^T reveals 15 open-reading frames (ORFs) encoding various agarases. In this study, extracellular proteins of YM01^T were precipitated by ammonium sulfate and separated by one-dimensional gel electrophoresis. The results of in-gel agarase activity assay and mass spectrometry analysis revealed that the protein, YM01-3, was an agarase with the most evident agarolytic activity. Agarase YM01-3, encoded by the YM01-3 gene, consisted of 420 amino acids with a calculated molecular mass of 46.9 kDa and contained a glycoside hydrolase family 16 β-agarase module followed by a RICIN superfamily in the C-terminal region. The YM01-3 gene was cloned and expressed in Escherichia coli. The recombinant agarase, YM01-3, showed optimum activity at pH 6.0 and 60 °C and had a K_m of 3.78 mg mL⁻¹ for agarose and a V_max of 1.14 × 10⁴ U mg⁻¹. YM01-3 hydrolyzed the β-1,4-glycosidic linkages of agarose, yielding neoagarotetraose and neoagarohexaose as the main products. Notably, YM01-3 was stable below 50 °C and retained 13% activity after incubation at 80 °C for 1 h, characteristics much different from other agarases. The present study highlights a thermostable agarase with great potential application value in industrial production.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.