Molecular cloning, characterization and enzymatic properties of a novel βeta-agarase from a marine isolate Psudoalteromonas sp. AG52

Brazilian Journal of Microbiology

Chulhong Oh²  Chamilani Nikapitiya²  Youngdeuk Lee²  Ilson Whang¹  Do-hyung Kang¹  Soo-jin Heo¹  Young-ung Choi¹  Jehee Lee² 

[1] ,Jeju National University Department of Marine Life Science ,Republic of Korea

关键词: Agar;    Aeromonas sp;    β-agarase;    Pseudoalteromonas sp;    GHF-16;    Neoagaro-oligosaccharides;   

DOI  :  10.1590/S1517-83822010000400006

来源: SciELO

【 摘 要 】

An agar-degrading Pseudoalteromonas sp. AG52 bacterial strain was identified from the red seaweed Gelidium amansii collected from Jeju Island, Korea. A β-agarase gene which has 96.8% nucleotide identity to Aeromonas β-agarase was cloned from this strain, and was designated as agaA. The coding region is 870 bp, encoding 290 amino acids and possesses characteristic features of the glycoside hydrolase family (GHF)-16. The predicted molecular mass of the mature protein was 32 kDa. The recombinant β-agarase (rAgaA) was overexpressed in Escherichia coli and purified as a fusion protein. The optimal temperature and pH for activity were 55 ºC and 5.5, respectively. The enzyme had a specific activity of 105.1 and 79.5 unit/mg toward agar and agarose, respectively. The pattern of agar hydrolysis demonstrated that the enzyme is an endo-type β-agarase, producing neoagarohexaose and neoagarotetraose as the final main products. Since, Pseudoalteromonas sp. AG52 encodes an agaA gene, which has greater identity to Aeromonas β-agarase, the enzyme could be considered as novel, with its unique bio chemical characteristics. Altogether, the purified rAgaA has potential for use in industrial applications such as development of cosmetics and pharmaceuticals.

【 授权许可】

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