Identification and characterization of a chitin deacetylase from a metagenomic library of deep-sea sediments of the Arctic Ocean.
BACKGROUND
The chemical and biological compositions of deep-sea sediments are interesting because of the underexplored diversity when it comes to bioprospecting. The special geographical location and climates make Arctic Ocean a unique ocean area containing an abundance of microbial resources.


METHODS
A metagenomic library was constructed based on the deep-sea sediments of Arctic Ocean. Part of insertion fragments of this library were sequenced. A chitin deacetylase gene, cdaYJ, was identified and characterized.


RESULTS
A metagenomic library with 2750 clones was obtained and ten clones were sequenced. Results revealed several interesting genes, including a chitin deacetylase coding sequence, cdaYJ. The CdaYJ is homologous to some known chitin deacetylases and contains conserved chitin deacetylase active sites. CdaYJ protein exhibits a long N-terminal and a relative short C-terminal. Phylogenetic analysis revealed that CdaYJ showed highest homology to CDAs from Alphaproteobacteria. The cdaYJ gene was subcloned into the pET-28a vector and the recombinant CdaYJ (rCdaYJ) was expressed in Escherichia coli BL21 (DE3). rCdaYJ showed a molecular weight of 43kDa, and exhibited deacetylation activity by using p-nitroacetanilide as substrate. The optimal pH and temperature of rCdaYJ were tested as pH7.4 and 28°C, respectively.


CONCLUSIONS
The construction of metagenomic library of the Arctic deep-sea sediments provides us an opportunity to look into the microbial communities and exploiting valuable gene resources. A chitin deacetylase CdaYJ was identified from the library. It showed highest deacetylation activity under slight alkaline and low temperature conditions. CdaYJ might be a candidate chitin deacetylase that possesses industrial and pharmaceutical potentials.
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Jinlin
J
Liu
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Zhijuan
Z
Jia
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Sha
S
Li
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Yan
Y
Li
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Qiang
Q
You
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Chunyan
C
Zhang
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Xiaotong
X
Zheng
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Guomei
G
Xiong
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Jin
J
Zhao
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China. Electronic address: qichao@mail.ccnu.edu.cn.
Chao
C
Qi
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China. Electronic address: cdcyang@mail.ccnu.edu.cn.
Jihong
J
Yang
D020561:Alphaproteobacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D000581:Amidohydrolases / Q000235:genetics* / Q000378:metabolism; D001110:Arctic Regions; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D003080:Cold Temperature; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D015723:Gene Library; D019015:Geologic Sediments / Q000382:microbiology; D054892:Metagenome; D058977:Molecular Sequence Annotation; D009792:Oceans and Seas; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D000581:Amidohydrolases; C019866:chitin deacetylase
Arctic Ocean; Characterization; Chitin deacetylase; Deep-sea sediment; Metagenomic library