Cloning and Expression of a Chitinase from an Antarctic Bacterium, Sanguibacter sp. KCTC10714

Abstract

We isolated a chitinase-producing bacterium strainKCTC10714 from sea sand that had been collected around the King Sejong Station, King George Island in Antarctica (62° 13′ S, 58° 47′ W). It was identified as Sanguibacter sp., based on the biochemical properties and 16S rRNA gene sequence. KCTC10714 chitinase degraded chitin to produce chitinoligomer and chitobiose. KCTC10714 chitinase showed enzyme activity in broad range of pH 4 - 9, and temperature from 0 to 70℃. At 0℃, it showed 70.9% of relative activity in comparison with 100% at 45℃. We cloned the chitinase gene from KCTC10714 using inverse PCR cloning method. KCTC10714 chitinase gene was 1,888 bp in length including 388 bp of 5'-UTR and 51 bp of 3'-UTR, and it was designated as chi21702. The ORF of chi21702 consisted of 1,449 bp (482 amino acid), and contained ChtBD3 (a chitin/cellulose binding domain) and an active site for chitinase family 18. We also confirmed that the recombinant protein of chi21702 made approximately 56 kDa after overexpression in E.coli system. The characterization of the recombinant Chi21702 is under investigation.