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 10–20 °C, indicating that they are psychrophilic bacteria. The alginate lyases produced by 11 strains showed the highest activity at 20–30 °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.

Niches of two polysaccharide-degrading Polaribacter isolates from the North Sea during a spring diatom bloom

“…The polysaccharide alginate is found in brown alga cell walls, and alginate lyase excreting Polaribacter have been described before as abundant members of epiphytic bacterial communities on Laminaria sp. brown alga (Dong et al, 2012).…”

“…This view is supported by high Flavobacteriia abundances in nutrient-rich habitats, such as aggregates of particulate organic matter (Williams et al, 2013) or in the microbiota of marine algae and invertebrates (Di Camillo et al, 2012;Dong et al, 2012). Also, so far sequenced genomes of marine Flavobacteriia have revealed clear adaptations towards biopolymer degradation (for example, Bauer et al, 2006;González et al, 2008;Woyke et al, 2009;Mann et al, 2013), as they feature high proportions of peptidase and glycoside hydrolase (GH) genes.…”

Screening of alginate lyase-excreting microorganisms from the surface of brown algae

“…For example, 21 alginate lyase-excreting strains were isolated from the surface of the Arctic Laminaria and some cold-adapted alginate lyases were identified (Dong et al 2012). More recently, Martin et al (2015) isolated and identified 14 alginate lyase-excreting strains associated with the brown alga Ascophyllum nodosum , including one novel strain of Marinomonas.…”

Marine Microbiological Enzymes: Studies with Multiple Strategies and Prospects

“…Liu et al [108] reported for the first time that the extracellular alginate lyase-like protein from Pseudomonas fluorescens exhibits high degradation activity for alginate. Dong and other scientists performed a study on bacteria isolated from the Arctic marine seaweed that produces alginate lyase [109]. In total, 65 bacterial strains were isolated from the kelp specimen, 21 of which exhibited alginate lyase activity.…”

“…In total, 65 bacterial strains were isolated from the kelp specimen, 21 of which exhibited alginate lyase activity. Among these isolates, 11 bacterial strains exhibited an optimum temperature between 20 °C and 30 °C, which indicates that the extracellular lyases are cryophilic enzymes [109]. Moreover, the bacterial strains Psychrobacter , Winogradskyella , Psychromonas and Polaribacter produce alginate lyase.…”