Paraglaciecola hydrolytica sp nov., a bacterium with hydrolytic activity against multiple seaweed-derived polysaccharides

A novel bacterial strain, S66(T), was isolated from eelgrass collected on the coastline of Zealand, Denmark. Polyphasic analyses involving phenotypic, phylogenetic and genomic methods were used to characterize strain S66(T). The strain was Gram-reaction-negative, rod-shaped, aerobic, and displayed growth at 10-25 degrees C (optimum 20-25 degrees C) and at pH 7-9 (optimum pH 7.5). Furthermore, strain S66(T) grew on seaweed polysaccharides agar, agarose, porphyran, kappa-carrageenan, alginate and laminarin as sole carbon sources. Major fatty acids were C-16:0, C-16:1 omega 7c and C-18:1 omega 7c. The respiratory quinone was determined to be Q-8, and major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content was determined to be 42.2 mol%. Phylogenetic analyses based on the 16S rRNA gene and GyrB sequence comparisons showed that the bacterium was affiliated with the genus Paraglaciecola within the family Alteromonadaceae of the class Gammaproteobacteria. The percentage similarity between the 16S rRNA gene and GyrB sequences of strain S66(T) and other members of the genus Paraglaciecola were 94-95% and 84-85 %, respectively. Based on the genome sequence of S66(T), the average nucleotide identity (ANI) between strain S66(T) and other members of the genus Paraglaciecola was 77-80 %, and DNA-DNA hybridization prediction showed values of less than 24% relatedness, respectively, between S66(T) and other species of the genus Paraglaciecola. The phenotypic, phylogenetic and genomic analyses support the hypothesis that strain S66(T) represents a novel species of the genus Paraglaciecola, for which the name Paraglaciecola hydrolytica sp. nov. is proposed. The type strain is S66(T) (=LMG 29457(T)=NCIMB 15060(T)=DSM 102834(T)).