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期刊论文

Characterization of Antifungal Chitinase from Marine Streptomyces sp. DA11 Associated with South China Sea Sponge Craniella Australiensis

李志勇Yue Han & Bingjie Yang & Fengli Zhang & Xiaoling Miao & Zhiyong Li

Mar Biotechnol (2009)11: 132-140,-0001,():

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摘要/描述

The gene cloning, purification, properties, kinetics, and antifungal activity of chitinase from marine Streptomyces sp. DA11 associated with South China sponge Craniella australiensis were investigated. Alignment analysis of the amino acid sequence deduced from the cloned conserved 451 bp DNA sequence shows the chitinase belongs to ChiC type with 80% similarity to chitinase C precursor from Streptomyces peucetius. Through purification by 80% ammonium sulfate, affinity binding to chitin and diethylaminoethyl-cellulose anion-exchange chromatography, 6.15-fold total purification with a specific activity of 2.95 Umg-1 was achieved. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed a molecular weight of approximately 34 kDa and antifungal activities were observed against Aspergillus niger and Candida albicans. The optimal pH, temperature, and salinity for chitinase activity were 8.0, 50℃, and 45g‰ psu, respectively, which may contribute to special application of this marine microbe-derived chitinase compared with terrestrial chitinases. The chitinase activity was increased by Mn2+, Cu2+, and Mg2+, while strongly inhibited by Fe2+ and Ba2+. Meanwhile, SDS, ethyleneglycoltetraacetic acid, urea, and ethylenediaminetetraacetic acid were found to have significantly inhibitory effect on chitinase activity. With colloidal chitin as substrates instead of powder chitin, higher Vmax (0.82 mg product/min•mg protein) and lower Km (0.019 mg/ml) values were achieved. The sponge’s microbial symbiont with chitinase activity may contribute to chitin degradation and antifungal defense. To our knowledge, it was the first time to study sponge-associated microbial chitinase.

【免责声明】以下全部内容由[李志勇]上传于[2011年04月29日 14时39分01秒],版权归原创者所有。本文仅代表作者本人观点,与本网站无关。本网站对文中陈述、观点判断保持中立,不对所包含内容的准确性、可靠性或完整性提供任何明示或暗示的保证。请读者仅作参考,并请自行承担全部责任。

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