title: Cloning and characterization of two thermo- and salt-tolerant oligoalginate lyases from marine bacterium Halomonas sp.
abstract: Two new alginate lyase genes, oalY1 and oalY2, have been cloned from the newly isolated marine bacterium Halomonas sp. QY114 and expressed in Escherichia coli The deduced alginate lyases, OalY1 and OalY2, belonged to polysaccharide lyase (PL) family 17 and showed less than 45% amino acid identity with all of the characterized oligoalginate lyases. OalY1 and OalY2 exhibited the highest activities at 45°C and 50°C, respectively. Both of them showed more than 50% of the highest activity at 60°C, and 20% at 80°C. In addition, they were salt-dependent and salt-tolerant since both of them showed the highest activity in the presence of 0.5 M NaCl and preserved 63% and 68% of activity in the presence of 3 M NaCl. Significantly, OalY1 and OalY2 could degrade both polyM and polyG blocks into alginate monosaccharides in an exo-lytic type, indicating that they are bifunctional alginate lyases. In conclusion, our study indicated that OalY1 and OalY2 are good candidates for alginate saccharification application, and the salt-tolerance may present an exciting new concept for biofuel production from native brown seaweeds.
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Yang
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Shangyong
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Wengong
authors.initials: W
authors.lastname: Yu
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China fhan@ouc.edu.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Han
mesh_terms: D000464:Alginates / Q000378:metabolism; D056804:Biofuels; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D020723:Glucuronic Acid / Q000378:metabolism; D020632:Halomonas / Q000201:enzymology* / Q000235:genetics; D006603:Hexuronic Acids / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D011133:Polysaccharide-Lyases / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism; D013379:Substrate Specificity; D000071436:Thermotolerance
chemical_list: D000464:Alginates; D056804:Biofuels; D006603:Hexuronic Acids; D012965:Sodium Chloride; D020723:Glucuronic Acid; D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase
keywords: biofuel; oligoalginate lyase; salt-tolerant; thermo-tolerant