Purification and Characterization of a Bifunctional Alginate Lyase from Pseudoalteromonas sp. SM0524

• Published in: Marine Drugs
• Main Authors: Bin-Bin Xie, Yu-Zhong Zhang, Xiu-Lan Chen, Chun-Bo Li, Jie Song, Sheng Dong, Jian-Wei Li
• Format: Article
• Language: English
• Published: MDPI AG 2011-01-01
• Subjects: bifunctional alginate lyase; Pseudoalteromonas sp. SM0524; alginate
• Online Access: http://www.mdpi.com/1660-3397/9/1/109/

An alginate lyase-producing bacterial strain, Pseudoalteromonas sp. SM0524, was screened from marine rotten kelp. In an optimized condition, the production of alginate lyase from Pseudoalteromonas sp. SM0524 reached 62.6 U/mL, suggesting that strain SM0524 is a good producer of alginate lyases. The bifunctional alginate lyasealy-SJ02 secreted by strain SM0524 was purified. Aly-SJ02 had an apparent molecular mass of 32 kDa. The optimal temperature and pH of aly-SJ02 toward sodium alginate was 50 °C and 8.5, respectively. The half life period of aly-SJ02 was 41 min at 40 °C and 20 min at 50 °C. Aly-SJ02 was most stable at pH 8.0. N-terminal sequence analysis suggested that aly-SJ02 may be an alginate lyase of polysaccharide lyase family 18. Aly-SJ02 showed activities toward both polyG (α-L-guluronic acid) and polyM (β-D-mannuronic acid), indicating that it is a bifunctional alginate lyase. Aly-SJ02 had lower Km toward polyG than toward polyM and sodium alginate. Thin layer chromatography and ESI-MS analyses showed that aly-SJ02 mainly released dimers and trimers from polyM and alginate, and trimers and tetramers from polyG, which suggests that aly-SJ02 may be a good tool to produce dimers and trimers from alginate.