Polaribacter lacunae sp. nov., isolated from a lagoon

An aerobic, Gram-stain-negative, rod-shaped bacterium, designated strain HMF2268T, was isolated from a lagoon in the Republic of Korea. Comparative 16S rRNA gene sequence analysis showed that strain HMF2268T belonged to the genus Polaribacter and was most closely related to Polaribacter huanghezhanensis SM1202T (96.8 % similarity). Cellular fatty acids were dominated by iso-C15 : 0, iso-C15 : 0 3-OH, anteiso-C15 : 0 and iso-C15 : 1 G. The predominant respiratory quinone was menaquinone-6 (MK-6). The major polar lipids were phosphatidylethanolamine, three unidentified aminolipids and two unidentified polar lipids. The DNA G+C content was 34.3 mol%. Based on the polyphasic taxonomic analyses, it is concluded that strain HMF2268T represents a novel species of the genus Polaribacter , for which the name Polaribacter lacunae sp. nov. is proposed. The type strain is HMF2268T (=KCTC 42191T=CECT 8862T)

Comparison of bacterial diversity and species composition in three endemic Baikalian sponges

Baikalian sponges are unique organisms with many species harboring symbiotic microbes that produce novel bioactive compounds. To investigate bacterial diversity of three species of Baikalian sponges, specimens of Lubomirskia baicalensis, Baikalospongia intermedia and Swartschewskia papyracea collected from Lake Baikal were processed by pyrosequencing. We found differences in the species composition and diversity in bacteria among these sponges. Cyanobacteria accounted for the highest proportion and the second group was Proteobacteria in three sponges. The bacterial communities in B. intermedia and L. baicalensis were highly similar but less similar to the bacterial community associated with S. papyracea. Diversity of the bacterial community in S. papyracea was higher than in L. baicalensis and B. intermedia. In particular, the relative abundance of Actinobacteria was higher in S. papyracea. Bacterial species in phyla Acidobacteria and Gemmatimonadetes were only found in S. papyracea.Sponge-symbionts have the ecological important functions and produce a diverse pharmacological metabolites. Bacteria associated with freshwater sponges have been much less studied. Our study describes diversity of bacteria in Baikalian sponges, specially, those of S. papyracea for the first time. We provide additional knowledge into freshwater sponge-associated microbiota