Characterization of a coldadapted and salttolera

Authors: Xiaohui Wang Naiyu Chi Fengwu Bai Yuguang Du Yong Zhao Heng Yin

Publish Date: 2016/01/20

Volume: 20, Issue: 2, Pages: 167-176

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Abstract

We have previously reported a nonprocessive endotype chitinase ChiA from a newly isolated marine psychrophilic bacterium Pseudoalteromonas sp DL6 In this study a processive exotype chitinase ChiC was cloned from the same bacterium and characterized in detail ChiC could hydrolyze crystalline chitin into GlcNAc2 as the only observed product It exhibited high catalytic activity even at low temperatures eg close to 0 °C or in the presence of 5 M NaCl suggesting that ChiC was a coldadapted and highly salttolerant chitinase ChiC could also hydrolyze other substrates including chitosan and Avicel indicating its broad substrate specificity Sequence features indicated that ChiC was a multidomain protein having a deep substratebinding groove that was regarded as characteristic of processive exochitinases Enzymatic hydrolysis of chitin by ChiC could be remarkably boosted in the presence of ChiA suggesting the synergy of ChiC and ChiA This work provided a new evidence to prove that marine psychrophilic bacteria utilized a synergistic enzyme system to degrade recalcitrant chitinThe study was financially supported by the program for National Hightech Research and Development Program 863 2014AA093604 National Science Foundation No 31500039 No 31300668 National Hightech Research and Development Program 863 2012AA021501 and the Key Deployment Program of Chinese Academy of Sciences KSZDEWZ0152 Dr Heng Yin was supported by Youth Innovation Promotion Association of Chinese Academy of Sciences 2015144

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