title: Cultivable alginate lyase-excreting bacteria associated with the Arctic brown alga Laminaria.
abstract: Although some alginate lyases have been isolated from marine bacteria, alginate lyases-excreting bacteria from the Arctic alga have not yet been investigated. Here, the diversity of the bacteria associated with the brown alga Laminaria from the Arctic Ocean was investigated for the first time. Sixty five strains belonging to nine genera were recovered from six Laminaria samples, in which Psychrobacter (33/65), Psychromonas (10/65) and Polaribacter (8/65) were the predominant groups. Moreover, 21 alginate lyase-excreting strains were further screened from these Laminaria-associated bacteria. These alginate lyase-excreting strains belong to five genera. Psychromonas (8/21), Psedoalteromonas (6/21) and Polaribacter (4/21) are the predominant genera, and Psychrobacter, Winogradskyella, Psychromonas and Polaribacter were first found to produce alginate lyases. The optimal temperatures for the growth and algiante lyase production of many strains were as low as 10&#8211;20 &#176;C, indicating that they are psychrophilic bacteria. The alginate lyases produced by 11 strains showed the highest activity at 20&#8211;30 &#176;C, indicating that these enzymes are cold-adapted enzymes. Some strians showed high levels of extracellular alginate lyase activity around 200 U/mL. These results suggest that these algiante lyase-excreting bacteria from the Arctic alga are good materials for studying bacterial cold-adapted alginate lyases.
authors.affiliation: State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Dong
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Xi-Ying
authors.initials: XY
authors.lastname: Zhang
authors.forename: Mei
authors.initials: M
authors.lastname: Shi
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Song
authors.forename: Xiu-Lan
authors.initials: XL
authors.lastname: Chen
authors.forename: Yu-Zhong
authors.initials: YZ
authors.lastname: Zhang
mesh_terms: D001110:Arctic Regions; D001419:Bacteria / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification; D007795:Laminaria / Q000382:microbiology*; D009792:Oceans and Seas; D011133:Polysaccharide-Lyases / Q000302:isolation & purification* / Q000378:metabolism; D013696:Temperature
chemical_list: D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase