Winogradskyella profunda sp. nov. isolated from the Chukchi Sea bottom sediments

Description and Whole-Genome Sequencing of Mariniflexile litorale sp. nov., Isolated from the Shallow Sediments of the Sea of Japan

A Gram-negative, aerobic, rod-shaped, non-motile, yellow-pigmented bacterium, KMM 9835T, was isolated from the sediment sample obtained from the Amur Bay of the Sea of Japan seashore, Russia. Phylogenetic analyses based on the 16S rRNA gene and whole genome sequences positioned the novel strain KMM 9835T in the genus Mariniflexile as a separate line sharing the highest 16S rRNA gene sequence similarities of 96.6% and 96.2% with Mariniflexile soesokkakense RSSK-9T and Mariniflexile fucanivorans SW5T, respectively, and similarity values of <96% to other recognized Mariniflexile species. The average nucleotide identity and digital DNA-DNA hybridization values between strain KMM 9835T and M. soesokkakense KCTC 32427T, Mariniflexile gromovii KCTC 12570T, M. fucanivorans DSM 18792T, and M. maritimum M5A1MT were 83.0%, 82.5%, 83.4%, and 78.3% and 30.7%, 29.6%, 29.5%, and 24.4%, respectively. The genomic DNA GC content of strain KMM 9835T was 32.5 mol%. The dominant menaquinone was MK-6, and the major fatty acids were iso-C15:0, iso-C15:1ω10c, and C15:0. The polar lipids of strain KMM 9835T consisted of phosphatidylethanolamine, two unidentified aminolipids, an unidentified phospholipid, and six unidentified lipids. A pan-genome analysis showed that the KMM 9835T genome encoded 753 singletons. The annotated singletons were more often related to transport protein systems (SusC), transcriptional regulators (AraC, LytTR, LacI), and enzymes (glycosylases). The KMM 9835T genome was highly enriched in CAZyme-encoding genes, the proportion of which reached 7.3%. Moreover, the KMM 9835T genome was characterized by a high abundance of CAZyme gene families (GH43, GH28, PL1, PL10, CE8, and CE12), indicating its potential to catabolize pectin. This may represent part of an adaptation strategy facilitating microbial consumption of plant polymeric substrates in aquatic environments near shorelines and freshwater sources. Based on the combination of phylogenetic and phenotypic characterization, the marine sediment strain KMM 9835T (=KCTC 92792T) represents a novel species of the genus Mariniflexile, for which the name Mariniflexile litorale sp. nov. is proposed.

Description and genome-wide analysis of Profundicola chukchiensis gen. nov., sp. nov., marine bacteria isolated from bottom sediments of the Chukchi Sea

Two Gram-negative, aerobic halophilic non-motile strains designated KMM 9713 and KMM 9724T were isolated from the bottom sediments sampled from the Chukchi Sea in the Arctic Ocean, Russia. The novel strains grew in 0.5-5% NaCl, at 7-42°C, and pH 5.5-10.5. Phylogenetic analyses based on 16S rRNA gene and whole genome sequences revealed that strains KMM 9713 and KMM 9724T were close to each other and shared the highest 16S rRNA gene sequence similarity of 91.28% with the type strain Ornithobacterium rhinotracheale DSM 15997T and 90.15-90.92% with the members of the genus Empedobacter in the family Weeksellaceae. Phylogenetic trees indicated that strains KMM 9713 and KMM 9724T formed a distinct line adjacent to their relative O. rhinotracheale DSM 15997T. The average nucleotide identity values between strain KMM 9724T and O. rhinotracheale DSM 15997T, Empedobacter brevis NBRC 14943T, and Moheibacter sediminis CGMCC 1.12708T were 76.73%, 75.78%, and 74.65%, respectively. The novel strains contained the predominant menaquinone MK-6 and the major fatty acids of iso-C17:0 3-OH, iso-C15:0 followed by iso-C17:1ω6. Polar lipids consisted of phosphatidylethanolamine, one an unidentified aminophospholipid, two unidentified aminolipids, and two or three unidentified lipids. The DNA G+C contents of 34.5% and 34.7% were calculated from genome sequence of the strains KMM 9713 and KMM 9724T, respectively. Based on the phylogenetic evidence and distinctive phenotypic characteristics, strains KMM 9713 and KMM 9724T are proposed to be classified as a novel genus and species Profundicola chukchiensis gen. nov., sp. nov. The type strain of Profundicola chukchiensis gen. nov., sp. nov. is strain KMM 9724T (= KACC 22806T).

Taxonomic study of nine new Winogradskyella species occurring in the shallow waters of Helgoland Roads, North Sea. Proposal of Winogradskyella schleiferi sp. nov., Winogradskyella costae sp. nov., Winogradskyella helgolandensis sp. nov., Winogradskyella vidalii sp. nov., Winogradskyella forsetii sp. nov., Winogradskyella ludwigii sp. nov., Winogradskyella ursingii sp. nov., Winogradskyella wichelsiae sp. nov., and Candidatus "Winogradskyella atlantica" sp. nov

Evaluation of bacterial succession with cultivation-dependent strategies during a spring phytoplankton bloom in the North Sea led to the isolation of 41 strains that affiliated with the genus Winogradskyella. Fifteen of the strains were selected for a taxonomic study after discarding clonal cultures. A thorough phylogenetic, genomic and phenotypic analysis of the isolates indicated that they represented eight new species that coexisted in North Sea waters. Molecular data revealed the existence of an as yet uncultivated novel species recurrently binned from the North Sea metagenomes. The metagenome-assembled genomes (MAGs) of this new Winogradskyella were used to classify it as a new Candidatus species. This study represented a new example of the use of the tandem approach of whole cell mass spectrometry linked to 16S rRNA gene sequencing in order to facilitate the discovery of new taxa by high-throughput cultivation, which increases the probability of finding more than a single isolate for new species. In addition, we demonstrated the reasons for classifying MAGs representing recurrently retrieved heterotrophic species that evade cultivation even after an important high-throughput effort. The taxonomic study resulted in the classification of eight new species and one new Candidatus species of the genus Winogradskyella for which we propose the names W. schleiferi sp. nov., W. costae sp. nov., W. helgolandensis sp. nov., W. vidalii sp. nov., W. forsetii sp. nov., W. ludwigii sp. nov., W. ursingii sp. nov., W. wichelsiae sp. nov., and Candidatus "W. atlantica" sp. nov.

Flavicella sediminum sp. nov., isolated from marine sediment

A novel, Gram-stain-negative, motile, flagellated, aerobic, rod-shaped (0.5-0.7 µm wide and 1.0-1.2 µm long) and faint-yellow strain, designated ALS 84^T, was isolated from marine sediment sampled at Ailian bay, Rongcheng, PR China. Growth occurred in the presence of 1-3 % (w/v) NaCl (optimum, 2 % NaCl), at pH 4.0-8.0 (pH 6.0-7.0) and at 8-30 °C (28 °C). The genome size was 4.37 Mbp. The G+C content of the genomic DNA was 33.6 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences suggested that strain ALS 84^T belongs to the genus Flavicella within the family Flavobacteriaceae, and is most closely related to Flavicella marina (95.6 % similarity). The major fatty acids (>10 %) were iso-C_{15 : 0} 3-OH (22.9 %), iso-C_{15 : 0} (14.0 %) and C_{16 : 0} (10.9 %). The major polar lipids were phosphatidylethanolamine and three unidentified lipids. Menaquinone-6 (MK-6) was identified as the respiratory quinone. On the basis of the phenotypic, phylogenetic and chemotaxonomic data obtained in the study, strain ALS 84^T is considered to represent a novel species of the genus Flavicella, for which the name Flavicella sediminum sp. nov. is proposed. The type strain of the novel species is strain ALS 84^T (=KCTC 62398^T=MCCC 1K03480^T).