Flavivirga spongiicola sp. nov. and Flavivirga abyssicola sp. nov., Isolated from Marine Environments

Two novel Gram-stain-negative, strictly-aerobic, rod-shaped (1.2 ± 3.4 μm × 0.3 ± 0.7 μm), and non-motile marine bacterial species, designated MEBiC05379T and MEBiC07777T, were isolated from a marine sponge Pseudaxinella sp. in Gangneung City and deep-sea sediments of the Ulleung basin in the East Sea of Korea, respectively. The 16S rRNA gene sequence analysis revealed high levels of similarities between these strains and members of the genus Flavivirga (97.0-98.4% sequence identities). Both novel strains revealed as mesophilic, neutrophilic in pH and slightly halophilic. Similar to those of other Flavivirga members, the primary cellular fatty acids of both strains were iso-C15:0, iso-C15:1 G, iso-C15:03-OH, and iso-C17:0 3-OH, with MEBiC05379T and MEBiC07777T containing relatively higher proportions of C12:0 and summed feature 3 (C16:1ω7c and/or C16:1ω6c). In both taxa, the major isoprenoid quinone was MK-6. The DNA G + C contents of MEBiC05379T and MEBiC07777T genomes were 32.62 and 32.46 mol%, respectively. Compared to other members of Flavivirga, both strains exhibited similar DNA G + C ratio and fatty acids pattern, yet enzyme expression and carbon sources utilization pattern were different. Genomes of the genus Flavivirga showed enzyme preferences to fucoidan and sulfated galactans. Considering the monophyly rule, AAI values delineate the genus Flavivirga from adjacent genera calculated to be 76.0-78.7%. Based on the phenotypic, genomic and biochemical data, strains for MEBiC05379T and MEBiC07777T thus represent two novel species in the genus Flavivirga, for which the names Flavivirga spongiicola sp. nov. (MEBiC05379T [= KCTC 92527 T = JCM 16662 T]), and Flavivirga abyssicola sp. nov. (MEBiC07777T [= KCTC 92563 T = JCM 36477 T]) are proposed.

Psychroserpens ponticola sp. nov. and Marinomonas maritima sp. nov., isolated from seawater

Two Gram-stain-negative, catalase- and oxidase-positive, aerobic non-motile and motile rod bacteria, strains MSW6T and RSW2T, were isolated from surface seawater. Strain MSW6T optimally grew at 20 °C, pH 7.0 and 3 % NaCl, while strain RSW2T optimally grew at 25 °C, pH 7.0-8.0 and 2 % NaCl. Strain MSW6T possessed menaquinone-6 as the major respiratory quinone, and its major fatty acids were iso-C15 : 1 G, iso-C15 : 0 and iso-C15 : 0 3-OH. The major polar lipid identified in strain MSW6T was phosphatidylethanolamine (PE). On the other hand, strain RSW2T had ubiquinone-8 as the predominant respiratory quinone, and its major fatty acids consisted of summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c), summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c) and C16 : 0. The major polar lipids identified in strain RSW2T were PE and phosphatidylglycerol. As the sole respiratory quinone, strain MSW6T possessed menaquinone-6, while strain RSW2T had ubiquinone-8. The DNA G+C contents of strains MSW6T and RSW2T were 31.9 and 43.4 mol%, respectively. Phylogenetic analyses based on 16S rRNA and core gene sequences showed that strain MSW6T formed a phylogenic lineage with Psychroserpens mesophilus KOPRI 13649T, while strain RSW2T formed a phylogenic lineage with Marinomonas primoryensis KMM 3633T. Strain MSW6T shared 97.9 % 16S rRNA gene sequence similarity and 80.7 % average nucleotide identity (ANI) ith P. mesophilus KOPRI 13649T, and strain RSW2T shared 99.1 % 16S rRNA gene sequence similarity and 93.1 % ANI with M. primoryensis KMM 3633T. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strains MSW6T and RSW2T represent novel species of the genera Psychroserpens and Marinomonas, respectively, for which the names Psychroserpens ponticola sp. nov. and Marinomonas maritima sp. nov. are proposed, respectively. The type strain of P. ponticola is MSW6T (=KACC 22338T=JCM 35022T) and the type strain of M. maritima is RSW2T (=KACC 22716T=JCM 35550T).

Bacterial Dynamics in the Accessory Nidamental Gland of Sepioteuthis lessoniana throughout Maturation

The accessory nidamental gland (ANG) is part of the reproduction organ in the majority of female cephalopods, including the bigfin reef squid Sepioteuthis lessoniana, an economically important fishery product. Microbes in Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia have been suggested to play a role in the maturation of the S. lessoniana ANG and are responsible for its color. However, the bacterial composition and dynamics of the different maturation stages of the ANG remain unclear. In the present study, we surveyed ANG-associated bacterial dynamics in wild-caught S. lessoniana at various developmental stages in different populations over 3 years. The results obtained showed that the ANG bacterial community shifted gradually and decreased in diversity throughout maturation. Verrucomicrobia occupied the ANG during the early stages in large numbers, and was replaced by Bacteroidia, Alphaproteobacteria, and Gammaproteobacteria in the later stages. Flavobacteriales and Alphaproteobacteria both appeared to contribute to pigmentation, while Bacteroidia, Alphaproteobacteria, and Gammaproteobacteria may be involved in enriching the heme biosynthesis pathway in the ANG with the maturation of S. lessoniana. The present results provide an open question of whether S. lessoniana actively selects the bacterial community in the ANG to adjust to its surrounding environment.

Palleronia sediminis sp. nov. and Flavivirga algicola sp. nov., two marine bacteria isolated from offshore areas near Weihai

Two bacterial strains, designated SS33^T and Y03^T, were isolated from marine sediment and marine red alga collected on the coast of Weihai, PR China. Based on the results of 16S rRNA gene sequence analysis, strain SS33^T was found to be closely related to Primorskyibacter marinus PX7^T, Pelagivirga dicentrarchi YLY04^T, Palleronia marisminoris DSM 26347^T and Maribius pontilimi GH1-23^T with 94.8, 94.6, 94.5 and 94.5 % sequence similarity; strain Y03^T was found to be closest to Flavivirga aquimarina EC2D5^T, Flavivirga eckloniae ECD14^T and Flavivirga amylovorans JC2681^T with 96.4, 96.1 and 96.0 % sequence similarity. Strain SS33^T grew at 4-37 °C (optimum, 33 °C), at pH 6.0-9.5 (optimum, pH 7.5-8.0) and in the presence of 0-10 % (w/v) NaCl (optimum, 3.0 %). Chemotaxonomic analysis of strain SS33^T showed that the predominant respiratory quinone was ubiquinone-10. The major fatty acids (>10.0 %) included C_18 : 1  ω7c and C_16 : 0. The major polar lipids included phosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid, one unidentified glycolipid, one unidentified polar lipid and two unidentified aminolipids. Strain Y03^T grew at 15-40 °C (optimum, 28 °C), at pH 6.5-8.0 (optimum, pH 7.0) and in the presence of 0.5-9.0 % (w/v) NaCl (optimum, 2.0%). Chemotaxonomic analysis showed that the predominant respiratory quinone was menaquinone-6. The major fatty acids (>10.0 %) included iso-C_15 : 0, iso-C_15 : 1 G, iso-C_17 : 0 3-OH and iso-C_15 : 0 3-OH. The major polar lipids included phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid and four unidentified polar lipids. Based on the polyphasic data, strain SS33^T is considered to represent a novel species of the genus Palleronia, for which the name Palleronia sediminis sp. nov. is proposed, with the type strain SS33^T (=KCTC 62986^T=MCCC 1H00387^T). Strain Y03^T is considered to represent a novel species of the genus Flavivirga, for which the name Flavivirga algicola sp. nov. is proposed, with the type strain Y03^T (=KCTC 72001^T=MCCC 1H00386^T).

Analysis of 1,000 Type-Strain Genomes Improves Taxonomic Classification of Bacteroidetes

Although considerable progress has been made in recent years regarding the classification of bacteria assigned to the phylum Bacteroidetes, there remains a need to further clarify taxonomic relationships within a diverse assemblage that includes organisms of clinical, piscicultural, and ecological importance. Bacteroidetes classification has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees and a limited number of phenotypic features. Here, draft genome sequences of a greatly enlarged collection of genomes of more than 1,000 Bacteroidetes and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa proposed long ago such as Bacteroides, Cytophaga, and Flavobacterium but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which can be considered valuable taxonomic markers. We detected many incongruities when comparing the results of the present study with existing classifications, which appear to be caused by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. The few significant incongruities found between 16S rRNA gene and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences and the impediment in using ordinary bootstrapping in phylogenomic studies, particularly when combined with too narrow gene selections. While a significant degree of phylogenetic conservation was detected in all phenotypic characters investigated, the overall fit to the tree varied considerably, which is one of the probable causes of misclassifications in the past, much like the use of plesiomorphic character states as diagnostic features.

Description of Lacinutrix salivirga sp. nov., a marine member of the family Flavobacteriaceae isolated from seawater

A novel marine bacterium, designated KMU-57^T, was isolated from seawater collected from the Republic of Korea, and it was characterized using polyphasic taxonomic methods. Strain KMU-57^T was Gram-stain-negative, strictly aerobic, rod-shaped, motile and dark-yellow-pigmented. Comparative analysis based on the 16S rRNA gene sequence showed the affiliation of the isolate with members of the family Flavobacteriaceae of the phylum Bacteroidetes, and it had the greatest sequence similarity (97.6%) to Lacinutrix jangbogonensis PAMC 27137^T. The DNA-DNA relatedness value between strain KMU-57^T and L. jangbogonensis PAMC 27137^T was 37.8 ± 2.2%. The DNA G + C content of strain KMU-57^T was 29.9 mol%; MK-6 was the major menaquinone with; iso-C15:1 G (18.6%) and C16:1 ω7c and/or C16:1 ω6c (15.8%) as the major (> 10%) cellular fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, three unidentified aminolipids, and five unidentified lipids. The strain represents a novel species of the genus Lacinutrix for which the name Lacinutrix salivirga sp. nov. is proposed. The type strain of L. salivirga sp. nov. is KMU-57^T (= KCTC 52878^T = NBRC 112845^T).

Flavivirga eckloniae sp. nov. and Flavivirga aquimarina sp. nov., isolated from seaweed Ecklonia cava

Two Gram-stain-negative, non-spore-forming, rod-shaped, aerobic and yellow-coloured bacterial strains, designated strains ECD14T and EC2D5T, were isolated from a seaweed Eckloniacava. The isolates required sea salts for growth. Flexirubin-type and carotenoid pigment was produced. The 16S rRNA gene sequence similarity between the two new strains was 95.5 %. Flavivirga amylovorans JC2681T was the nearest neighbour of strains ECD14T and EC2D5T with 96.5 and 96.8 % 16S rRNA gene sequence similarity, respectively. The common major fatty acids and respiratory quinones were iso-C15 : 0, iso-C15 : 1 G and unknown 13.565 and menaquinone 6 (MK-6), respectively. The common major polar lipids were phosphatidylethanolamine, an unknown amino lipid and an unknown lipid. The DNA G+C contents of strains ECD14T and EC2D5T were 33 and 31 mol%, respectively. On the basis of the polyphasic characterization of the two strains, it is suggested that the two isolates represent novel species of the genus Flavivirga, for which the names Flavivirga eckloniae sp. nov. (type strain, ECD14T=KCTC 52352T=JCM 31797T) and Flavivirga aquimarina sp. nov. (type strain, EC2D5T=KCTC 52353T=JCM 31796T) are proposed.

Flavirhabdus iliipiscaria gen. nov., sp. nov., isolated from intestine of flounder (Paralichthys olivaceus) and emended descriptions of the genera Flavivirga, Algibacter, Bizionia and Formosa

A Gram-stain-negative, orange-coloured, rod-shaped bacterium, designated strain Th68T, was isolated from the intestine of flounder (Paralichthys olivaceus). The isolate required sea salts for growth. Gliding motility was not observed. Flexirubin-type pigments were present. 16S rRNA gene sequence analysis indicated that strain Th68T represented a distinct phyletic line within the family Flavobacteriaceae with less than 96.1 % similarity to members of the recognized genera of the family. The DNA G+C content was 33.0 mol%. The major fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and iso-C15 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and two unidentified polar lipids. Menaquinone 6 (MK-6) was the only respiratory quinone. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain Th68T represents a novel species of a new genus in the family Flavobacteriaceae , for which the name Flavirhabdus iliipiscaria gen. nov., sp. nov. is proposed. The type strain of Flavirhabdus iliipiscaria is Th68T ( = JCM 18637T = KCTC 32141T).

Lacinutrix jangbogonensis sp. nov., a psychrophilic bacterium isolated from Antarctic marine sediment and emended description of the genus Lacinutrix

A Gram-negative, strictly aerobic, non-motile, rod-shaped and psychrophilic bacterial strain, PAMC 27137(T), was isolated from the marine sediment of the Ross Sea, Antarctica. Strain PAMC 27137(T) was observed to grow at 4-10 °C, at pH 6.5-7.5 and in the presence of 2.5-4.0 % (w/v) sea salts. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain PAMC 27137(T) belongs to the genus Lacinutrix showing the high similarities with Lacinutrix mariniflava JCM 13824(T) (97.6 %) and Lacinutrix algicola JCM 13825(T) (97.1 %). Genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strain PAMC 27137(T) is clearly distinguished from the most closely related Lacinutrix species. The major fatty acids (>5 %) were identified as iso-C15:1 G (19.9 %), iso-C15:0 (19.3 %), iso-C17:0 3-OH (11.3 %), summed feature 9 (C16:0 10-methyl and/or iso-C17:1 ω9c as defined by MIDI, 9.1 %), iso-C15:0 3-OH (7.5 %), and anteiso-C15:1 A (5.8 %). The polar lipids were found to consist of phosphatidylethanolamine, an unidentified aminolipid, an unidentified aminophospholipid, and five unidentified phospholipids. The major respiratory quinone was identified as MK-6. The genomic DNA G+C content was determined to be 32.1 mol%. Based on the data from this polyphasic taxonomic study, strain PAMC 27137(T) is considered to represent a novel species of the genus Lacinutrix, for which the name Lacinutrix jangbogonensis sp. nov. is proposed. The type strain is PAMC 27137(T) (=KCTC 32573(T)=JCM 19883(T)).

Sabulilitoribacter multivorans gen. nov., sp. nov., a polysaccharide-degrading bacterium of the family Flavobacteriaceae isolated from seashore sand

A Gram-negative, aerobic, non-flagellated, non-gliding and rod-shaped bacterial strain, designated M-M16(T), was isolated from seashore sand around a seaweed farm on the South Sea, South Korea, and its taxonomic position was investigated by using a polyphasic study. Strain M-M16(T) grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2 % (w/v) NaCl. Strain M-M16(T) exhibited the highest 16S rRNA gene sequence similarity values to the type strains of Gaetbulibacter lutimaris (96.5 %) and Flaviramulus basaltis (95.8 %). Neighbour-joining and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain M-M16(T) clustered with the type strains of Gaetbulibacter species and F. basaltis. Strain M-M16(T) contained MK-6 as the predominant menaquinone and iso-C15:1 G, iso-C15:0 and iso-C17:0 3-OH as the major fatty acids. The major polar lipids detected in strain M-M16(T) were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain M-M16(T) was 37.4 mol%. The phylogenetic and chemotaxonomic data and other phenotypic properties revealed that strain M-M16(T) represents a novel genus and species within the family Flavobacteriaceae, for which the name Sabulilitoribacter multivorans gen. nov., sp. nov. is proposed. The type strain of S. multivorans is M-M16(T) (= KCTC 32326(T) = CCUG 63831(T)).

Psychroserpens damuponensis sp. nov., isolated from seawater

A novel bacterium, designated strain F051-1T, isolated from a seawater sample collected from the coast at Damupo beach in Pohang, Korea, was investigated in a polyphasic taxonomic study. Cells were yellow-pigmented, strictly aerobic, Gram-staining-negative and rod-shaped. The temperature, pH and NaCl ranges for growth were 4–30 °C, pH 6.0–9.0 and 1.0–6.0 % (w/v), respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain F051-1T belongs to the genus Psychroserpens in the family Flavobacteriaceae . Its closest relatives were Psychroserpens burtonensis ACAM 188T (96.8 % 16S rRNA gene sequence similarity) and Psychroserpens mesophilus KOPRI 13649T (95.7 %). The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and anteiso-C15 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, two unidentified aminolipids, one unidentified phospholipid and eight unidentified lipids. The major respiratory quinone was menaquinone-6 and the genomic DNA G+C content of the strain was 33.5 mol%. On the basis of phenotypic, phylogenetic and genotypic data, strain F051-1T represents a novel species within the genus Psychroserpens , for which the name Psychroserpens damuponensis sp. nov. is proposed. The type strain is F051-1T ( = KCTC 23539T  = JCM 17632T).

Lacinutrix himadriensis sp. nov., a psychrophilic bacterium isolated from a marine sediment, and emended description of the genus Lacinutrix

A novel gram-negative, rod-shaped, non-motile, psychrophilic bacterium, designated strain E4-9a(T), was isolated from a marine sediment sample collected at a depth of 276 m from Kongsfjorden, Svalbard, in the Arctic Ocean. The colony colour was golden yellow. Strain E4-9a(T) was positive for amylase activity at 5 °C. The predominant fatty acids were iso-C(15 : 1) G (21.8 %), anteiso-C(15 : 0) (19.1 %), anteiso-C(15 : 1) A (18.6 %), iso-C(15 : 0) (13.8 %) and iso-C(16 : 1) H (6.4 %). Strain E4-9a(T) contained MK-6 as the major respiratory quinone. The polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids (AL1, AL4 and AL5), an unidentified phospholipid and four unidentified lipids (L1, L4 to L6). Based on 16S rRNA gene sequence similarity, it was ascertained that the closest related species to E4-9a(T) were Lacinutrix copepodicola, L. algicola and L. mariniflava, with sequence similarity to the respective type strains of 98.5, 96.5 and 95.8 %. Phylogenetic analysis showed that strain E4-9a(T) clustered with the type strain of L. copepodicola and with those of L. algicola and L. mariniflava at distances of 1.5 and 4.8 % (98.5 and 95.2 % similarity), respectively. However, DNA-DNA hybridization with L. copepodicola DJ3(T) showed 59 % relatedness with respect to strain E4-9a(T). The DNA G+C content of strain E4-9a(T) was 29 mol%. Based on the results of DNA-DNA hybridization and phenotypic data, it appears that strain E4-9a(T) represents a novel species of the genus Lacinutrix, for which the name Lacinutrix himadriensis sp. nov. is proposed. The type strain is E4-9a(T) ( = CIP 110310(T)  = KCTC 23612(T)).