title: Cryoprotective properties and preliminary characterization of exopolysaccharide (P-Arcpo 15) produced by the Arctic bacterium Pseudoalteromonas elyakovii Arcpo 15.
abstract: Twenty-two bacterial strains that secrete exopolysaccharides (EPS) were isolated from marine samples obtained from the Chukchi Sea in the Arctic Ocean; of these, seven strains were found to be capable of producing cryoprotective EPS. The ArcPo 15 strain was isolated based on its ability to secrete large amounts of EPS, and was identified as Pseudoalteromonas elyakovii based on 16S rDNA analysis. The EPS, P-ArcPo 15, was purified by protease treatment and gel filtration chromatography. The purified EPS (P-ArcPo 15) had a molecular mass of 1.7 × 10(7) Da, and its infrared spectrum showed absorption bands of hydroxyl and carboxyl groups. The principal sugar components of P-ArcPo 15 were determined to be mannose and galacturonic acid, in the ratio of 3.3:1.0. The cryoprotective properties of P-ArcPo 15 were characterized by an Escherichia coli viability test. In the presence of 0.5% (w/v) EPS, the survival percentage of E. coli cells was as high as 94.19 ± 7.81% over five repeated freeze-thaw cycles. These biochemical characteristics suggest that the EPS P-ArcPo 15 may be useful in the development of cryoprotectants for biotechnological purposes, and we therefore assessed the utility of this novel cryoprotective EPS.
authors.affiliation: a Division of Life Sciences, Korea Polar Research Institute , Incheon , South Korea.|b Interdisciplinary Program for Bioengineering, Seoul National University , Seoul , South Korea.
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: b Interdisciplinary Program for Bioengineering, Seoul National University , Seoul , South Korea.|c School of Chemical and Biological Engineering, Institute of Bioengineering, Seoul National University , Seoul , South Korea.|d School of Chemical and Biological Engineering, Institute of Molecular Biology and Genetics, Seoul National University , Seoul , South Korea.
authors.forename: Byung-Gee
authors.initials: BG
authors.lastname: Kim
authors.affiliation: a Division of Life Sciences, Korea Polar Research Institute , Incheon , South Korea.
authors.forename: Ha Ju
authors.initials: HJ
authors.lastname: Park
authors.affiliation: a Division of Life Sciences, Korea Polar Research Institute , Incheon , South Korea.
authors.forename: Joung Han
authors.initials: JH
authors.lastname: Yim
mesh_terms: D001110:Arctic Regions; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D003451:Cryoprotective Agents / Q000737:chemistry*; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D031161:Pseudoalteromonas / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D003451:Cryoprotective Agents; D011135:Polysaccharides, Bacterial
keywords: Arctic bacterium; Pseudoalteromonas elyakovii; carbohydrate CPAs; cryoprotectant; cryoprotective properties; exopolysaccharide