A novel bacterial type II L-asparaginase and evaluation of its enzymatic acrylamide reduction in French fries

作者：Sun, Zhibin; Qin, Ran; Li, Ding; Ji, Kai; Wang, Ting; Cui, Zhongli; Huang, Yan^*

来源：International Journal of Biological Macromolecules, 2016, 92: 232-239.

DOI：10.1016/j.ijbiomac.2016.07.031

• L-Asparaginase
• Aquabacterium sp A7-Y
• Food processing

This study reports the identification of a novel bacterial type II L-asparaginase, abASNase2, from Aquabacterium sp. A7-Y. The enzyme contains 319 amino acids and shared 35% identity with Escherichia coli type L-asparaginase (EcAII), a commercial enzyme trademarked Elspar (R) that is widely used for medical applications. abASNase2 had high specific activity (458.9 U/mg) toward L-asparagine, very low activity toward L-glutamine and D.-glutamine and no activity toward D-asparagine. The optimal enzymatic activity conditions for abASNase2 were found to be 50 mM Tris-HCl buffer (pH 9.0) at 60 degrees C. It was very stable in the pH range of 7.0-11.0 and exhibited up to 80% relative activity after 2 h below 40 degrees C. The K-m and k(cat) of abASNase2 were 1.8 x 10(-3) M and 241.9 s(-1), respectively. In addition, abASNase2's ability to remove acrylamide from fried potato strips was evaluated. Compared to untreated potato strips (acrylamide content: 0.823 +/- 0.0457 mg/kg), 88.2% acrylamide was removed in the abASNase2-treated group (acrylamide content: 0.097 +/- 0.0157 mg/kg). These results indicate that the novel L-asparaginase abASNase2 is a potential candidate for applications in the food processing industry.

• 出版日期2016-11
• 单位南京农业大学