Celeribacter neptunius gen. nov., sp. nov., a new member of the class Alphaproteobacteria

A whitish Gram-negative, motile, aerobic bacterium, designated strain H 14T, was isolated from seawater collected at St Kilda beach in Port Phillip Bay, Melbourne, Australia. Analysis of 16S rRNA gene sequences revealed that the organism belonged to the Roseobacter lineage of the class Alphaproteobacteria, forming a distinct evolutionary lineage at the genus level. Strain H 14T was distantly related to the genera Nautella, Ruegeria and Pseudoruegeria (family Rhodobacteraceae). Strain H 14T was unable to degrade gelatin, casein, chitin, agar and starch, did not produce any carotenoids, did not possess bacteriochlorophyll a and had a limited ability to utilize carbon sources. Strain H 14T grew with concentrations of 1–8 % (w/v) NaCl and over a temperature range of 5–35 °C. Phosphatidylglycerol was the major phospholipid (90 %); phosphatidylcholine (7.9 %) and phosphatidylethanolamine (2.0 %) were present in minor quantities. The predominant fatty acids were C18 : 17c (82.4 %), C18 : 19c (5.1 %) and C18 : 0 (3.8 %). The DNA G+C composition for strain H 14T was 59.1 mol%. Based on the results of physiological, biochemical, chemotaxonomic and phylogenetic investigations, a new genus, Celeribacter gen. nov., with the type species Celeribacter neptunius sp. nov. is proposed. The type strain of the type species is H 14T (=KMM 6012T=CIP 109922T)

Winogradskyella exilis sp. nov., isolated from the starfish Stellaster equestris, and emended description of the genus Winogradskyella

A pale yellowish pigmented non motile strain 022-2-26T was isolated from a starfish Stellaster equestris. Gram-negative, short rod-shaped, nonmotile bacterium was chemoorganotrophic, alkalitolerant, and mesophilic. The type strain 022-2-26T contained MK-6 as the predominant menaquinone. The major cellular fatty acids were iso-15:0, iso-15:1, 15:0, iso-15:0-2OH and iso-17:0-3OH (together representing 86.4% of the total fatty acids). The DNA base composition was 30.1 mol% GC. A 16S rRNA gene sequence of the type strain 022-2-26T was determined and phylogenetic analyses revealed that 022-2-26T formed a robust clade (confirmed by neighbor-joining, parsimony and maximum-likelihood algorithms and 95% of bootstrap replication) with species of the genus Winogradskyella. The closest related species was Winogradskyella poriferorum UST030701-295T showing a similarity of 96% (59 differences between sequences). On the basis of the phenotypic, chemotaxonomic characteristics and phylogenetic evidence, it is suggested that the bacteria be classified as a novel species, Winogradskyella exilia sp. nov. The type strain is 022-2-26T (KMM 6013T = CIP 109976T)

Hydrolysis of Fucoidan by Fucoidanase Isolated from the Marine Bacterium, Formosa algae

marine drug

Fucoidan Sulfatases from Marine Bacterium Wenyingzhuangia fucanilytica CZ1127T

Fucoidans belong to a structurally heterogeneous class of sulfated polysaccharides isolated from brown algae. They have a wide spectrum of biological activities. The complex structures of these polysaccharides hinder structure-activity relationships determination. Fucoidan sulfatases can make useful tools for the determination of the fine chemical structure of fucoidans. In this study, identification and preparation of two recombinant sulfatases able to catalyze the cleavage of sulfate groups from fragments of fucoidan molecules is described for the first time. Two genes of sulfatases swf1 and swf4 of the marine bacterium Wenyingzhuangia fucanilytica CZ1127T were cloned and the proteins were produced in Escherichia coli cells. Sulfatases SWF1 and SWF4 are assigned to S1_17 and S1_25 subfamilies of formylglycine-dependent enzymes of S1 family (SulfAtlas). Some molecular and biochemical characteristics of recombinant fucoidan sulfatases have been studied. Detailed specificity and catalytic features of sulfatases were determined using various sulfated fucooligosaccharides. Structures of products produced by SWF1 and SWF4 were established by nuclear magnetic resonance (NMR) spectroscopy. Based on the obtained data, the enzymes are classified as fucoidan exo-2O-sulfatase (SWF1) and fucoidan exo-3O-sulfatase (SWF4). In addition, we demonstrated the sequential action of sulfatases on 2,3-di-O-sulfated fucooligosacchrides, which indicates an exolitic degradation pathway of fucoidan by a marine bacterium W. fucanilytica CZ1127T