Periódicos Brasileiros em Medicina Veterinária e Zootecnia

p. 683-690

Purification and characterization of cold-adapted beta-agarase from an Antarctic psychrophilic strain

Li, JiangHu, QiushiLi, YuquanXu, Yuan

<p>An extracellular β-agarase was purified from <italic>Pseudoalteromonas</italic> sp. NJ21, a Psychrophilic agar-degrading bacterium isolated from Antarctic Prydz Bay sediments. The purified agarase (Aga21) revealed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular weight of 80 kDa. The optimum pH and temperature of the agarase were 8.0 and 30 °C, respectively. However, it maintained as much as 85% of the maximum activities at 10 °C. Significant activation of the agarase was observed in the presence of Mg<sup>2+</sup>, Mn<sup>2+</sup>, K<sup>+</sup>; Ca<sup>2+</sup>, Na<sup>+</sup>, Ba<sup>2+</sup>, Zn<sup>2+</sup>, Cu<sup>2+</sup>, Co<sup>2+</sup>, Fe<sup>2+</sup>, Sr<sup>2+</sup> and EDTA inhibited the enzyme activity. The enzymatic hydrolyzed product of agar was characterized as neoagarobiose. Furthermore, this work is the first evidence of cold-adapted agarase in Antarctic psychrophilic bacteria and these results indicate the potential for the Antarctic agarase as a catalyst in medicine, food and cosmetic industries.</p>.(AU)

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