Yaping Du

Roseovarius nanhaiticus sp. nov., a member of the Roseobacter clade isolated from marine sediment.

An aerobic, Gram-staining-negative, rod or ovoid-shaped bacterial isolate, strain NH52J(T), was isolated from a sandy sediment sample from the South China Sea. Strain NH52J(T) exhibited tumbling motility, formed beige or faint pink colonies, gave a positive reaction in tests for catalase and oxidase and required NaCl for growth. Optimal growth was observed at pH 7.8-9.3, at 30 degrees C and in the presence of 2.0-4.0 % (w/v) NaCl. The novel strain did not synthesize bacteriochlorophyll a, and the DNA G+C content was 62 %. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(18 : 1)omega7c 11-methyl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH52J(T) was affiliated to the genus Roseovarius of the class Alphaproteobacteria. Roseovarius pacificus and Roseovarius aestuarii were the most closely related recognized species to strain NH52J(T) with 16S rRNA gene sequence similarity values of 95.0 and 95.7 %, respectively. Sequence similarity values between strain NH52J(T) and other phylogenetically related species were all below 95.0 %. Based on the phenotypic, chemotaxonomic and phylogenetic data presented, strain NH52J(T) is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius nanhaiticus sp. nov. is proposed. The type strain is NH52J(T) (=LMG 24840(T)=CCTCC AB 208317(T)=MCCC 1A03543(T)).

Leisingera nanhaiensis sp. nov., isolated from marine sediment

An aerobic, Gram-staining-negative, motile, rod-shaped bacterium, strain NH52F(T), was isolated from a sandy sediment sample taken from the South China Sea. On M2 agar medium (a complex medium), colonies were beige in colour. The isolate showed highest 16S rRNA gene sequence similarities to members of the genera Leisingera (96.7 % similarity), Phaeobacter (95.4-96.0 %) and Marinovum (94.1 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH52F(T) formed a distinct cluster with Leisingera methylohalidivorans MB2(T) and Leisingera aquimarina LMG 24366(T). Optimal growth was observed at pH 7.0-8.5 and 25 degrees C and the new isolate required the presence of 1-4 % (w/v) NaCl. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) 2-OH, C(10 : 0) 3-OH, C(12 : 0) 3-OH, C(16 : 0) and 11-methyl C(18 : 1)omega7c. The DNA G+C content was 60.5 mol%. The phylogenetic and chemotaxonomic characteristics of strain NH52F(T) were similar to those of the genus Leisingera. However, the differences in phenotypic properties and the 16S rRNA gene similarity values demonstrated that the new isolate differed from recognized species of the genus Leisingera. On the basis of phenotypic, chemotaxonomic and phylogenetic data, this organism should be classified as a representative of a novel species in the genus Leisingera, for which the name Leisingera nanhaiensis sp. nov. is proposed. The type strain is NH52F(T) (=LMG 24841(T)=CCTCC AB 208316(T)=MCCC 1A04178(T)).

Arenibacter nanhaiticus sp. nov., isolated from marine sediment of the South China Sea.

An aerobic, Gram-stain-negative, rod-shaped bacterial isolate, strain NH36A(T), was isolated from a sandy sediment sample from the South China Sea. Colonies of the isolate were dark orange on M2 agar. Optimal growth was observed at pH 7.0-8.5, 30 degrees C and in the presence of 0.5-4.0 % (w/v) NaCl. The major fatty acids were C(15 : 0), iso-C(15 : 0), anteiso-C(15 : 0), iso-C(15 : 1), iso-C(15 : 0) 3-OH, iso-C(17 : 0) 3-OH and summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c). The DNA G+C content was 38.9 mol%. 16S rRNA gene sequence analysis revealed that strain NH36A(T) was most closely related to members of the genus Arenibacter, exhibiting 94.3-96.2 % sequence similarity to the type strains of Arenibacter species. On the basis of phenotypic, chemotaxonomic and phylogenetic data, this organism should be classified as a representative of a novel species in the genus Arenibacter. The name Arenibacter nanhaiticus sp. nov. is proposed and the type strain is NH36A(T) (=LMG 24842(T)=CCTCC AB 208315(T)=MCCC 1A04137(T)).

Meridianimaribacter flavus gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from marine sediment of the South China Sea

A Gram-staining-negative, rod-shaped marine bacterium, designated strain NH57N(T), isolated from sandy sediment in the Mischief Reef of the South China Sea, was characterized based on its physiological and biochemical features, fatty acid profile and phylogenetic position. 16S rRNA gene sequence analysis revealed a clear affiliation with the family Flavobacteriaceae. Strain NH57N(T) showed the closest phylogenetic relationship with members of the genera Gaetbulibacter, Gelidibacter, Subsaxibacter, Subsaximicrobium and Yeosuana; levels of 16S rRNA gene sequence similarity between strain NH57N(T) and the type strains of related species ranged from 94.9 to 91.2 %. Cells of strain NH57N(T) were motile by gliding and grew on solid media as yellow colonies at 9-37 degrees C, pH 6.5-8.5 and in the presence of 0.5-4.0 % NaCl. The DNA G+C content was 32.7 mol% and the predominant fatty acids were iso-C(15 : 1) (22.7 % of the total), iso-C(15 : 0) (20.7 %), iso-C(17 : 0) 3-OH (9.5 %), iso-C(16 : 0) 3-OH (8.3 %), C(15 : 0) (7.8 %) and iso-C(15 : 0) 3-OH (5.8 %). Based on the physiological and phylogenetic data, and on the fatty acid composition, strain NH57N(T) is considered to represent a novel species of a new genus in the family Flavobacteriaceae, for which the name Meridianimaribacter flavus gen. nov., sp. nov. is proposed. The type strain of Meridianimaribacter flavus is NH57N(T) (=CCTCC AB 208318(T)=LMG 24839(T)=MCCC 1A03544(T)).

Halovulum dunhuangense gen. nov., sp nov., isolated from a saline terrestrial spring

A bacterial strain, YYQ-30(T), isolated from a mixed water-sand-sediment sample collected from a terrestrial spring located in Dunhuang, China, was characterized with respect to its morphology, physiology and taxonomy. Cells of the strain were Gram-stain-negative, aerobic, oxidase- and catalase-positive, non-flagellated, oval to rod-shaped (0.5-1.0 μm wide and 1.1-6.6 μm long) and divided by binary fission. Growth was observed in the presence of 0-10.0% (w/v) NaCl with optimal growth at 0-3.0%, at pH 6.0-9.0 (optimum pH 7.0-8.5) and at 10-45 °C (optimum 30-37 °C). The isolate could reduce nitrate to nitrite and hydrolyse aesculin and gelatin (weakly), but was unable to degrade Tween 80 or starch. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YYQ-30(T) belongs to the family Rhodobacteraceae and forms a distinct lineage with the type strain of Albimonas donghaensis and forms a branch within a cluster constituted by the type strains of species of the genera Albimonas, Rhodovulum, Albidovulum, Haematobacter and Tropicimonas; levels of 16S rRNA gene sequence similarity between strain YYQ-30(T) and members of related genera ranged from 94.1 to 89.7%. Strain YYQ-30(T) contained Q-10 as the predominant ubiquinone and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 70.0%), C18 : 0 (9.5%), summed feature 2 (one or more of C14  :  0 3-OH, iso-C16  :  1 I and C12  :  0 aldehyde; 6.9%) and 11-methyl C18 : 1ω7c (6.0%) as the principal fatty acids. The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three unidentified phospholipids, two unidentified aminolipids and five unknown lipids. The pufLM gene was detected. The G+C content of the genomic DNA was 71.7 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic data obtained in this study, strain YYQ-30T is considered to represent a novel species in a new genus within the family Rhodobacteraceae, for which the name Halovulum dunhuangense gen. nov., sp. nov. is proposed. The type strain of Halovulum dunhuangense is YYQ-30(T) ( = LMG 27418(T) = MCCC 1A06483(T)).

Zunongwangia atlantica sp. nov., isolated from deep-sea water.

A taxonomic study was carried out on strain 22II14-10F7(T), which was isolated from the deep-sea water of the Atlantic Ocean with oil-degrading enrichment. The bacterium was Gram-stain-negative, oxidase- and catalase-positive and rod-shaped. Growth was observed at salinities from 0.5 to 15 % and at temperatures from 4 to 37 °C; it was unable to hydrolyse Tween 40, 80 or gelatin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II14-10F7(T) represented a member of the genus Zunongwangia, with highest sequence similarity of 97.3 % to Zunongwangia profunda SM-A87(T), while the similarities to other species were all below 94.0 %. The DNA-DNA hybridization estimate of the similarity between strain 22II14-10F7(T) and Z. profunda SM-A87(T) was 27.20±2.43 % according to their genome sequences. The principal fatty acids were iso-C15 : 0, anteiso-C15 : 0 , iso-C15 : 1 G, iso-C17 : 0 3-OH, summed feature 3 (C16 : 1ω7c/ω6c) and summed feature 9 (iso-C17 : 1ω9c or C16 : 0 10-methyl). The G+C content of the chromosomal DNA was 35.5 mol%. The major respiratory quinone was determined to be MK-6. Phosphatidylethanolamine (PE), two aminolipids (AL1 and AL2) and five unknown lipids (L1-L5) were present. The combined genotypic and phenotypic data show that strain 22II14-10F7(T) represents a novel species of the genus Zunongwangia, for which the name Zunongwangia atlantica sp. nov. is proposed, with the type strain 22II14-10F7(T) ( = CGMCC1.12470(T) = LMG 27421(T) = MCCC 1A06481(T)).

Roseovarius atlanticus sp. nov., isolated from surface seawater of the Atlantic Ocean.

A taxonomic study was carried out on strain R12BT, which was isolated from surface seawater of the Atlantic Ocean. The bacterium was observed to be rod-shaped, Gram-stain-negative, oxidase-positive and weakly positive for catalase. Growth was observed at salinities of 0.5-15 % and at temperatures of 4-45 °C. The isolate was incapable of nitrate reduction and hydrolysis of gelatin, Tween 80 and aesculin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R12BT belonged to the genus Roseovarius, with highest sequence similarity to Roseovarius indicus B108T (97.2 % 16S rRNA gene sequence similarity), followed by Roseovarius halotolerans HJ50T (96.8 %); other species of genus Roseovarius shared 93.0-96.2 % sequence similarities. The DNA-DNA hybridization estimate value between strain R12BT and R. indicus B108T was 23.2 ± 2.4 %. The average nucleotide identity between strain R12BT and R. indicus B108T was 77.1 %. The principal fatty acids were summed feature 8 (C18 : 1ω7c/ω6c) and C16 : 0. The G+C content of the chromosomal DNA was 63.6 mol%. The respiratory quinone was determined to be Q-10. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, two aminolipids, two phospholipids and some unidentified lipids were present. The combined genotypic and phenotypic data show that strain R12BT represents a novel species of the genus Roseovarius, for which the name Roseovarius atlanticus sp. nov. is proposed, with the type strain R12BT ( = MCCC 1A09786T = KCTC 42506T).

Marinibacterium profundimaris gen. nov., sp. nov., isolated from deep seawater

A taxonomic study was carried out on strain 22II1-22F33T, which was isolated from deep seawater of the Atlantic Ocean. The bacterium was Gram-stain-negative, oxidase-positive and weakly catalase-positive, oval in shape without flagellum. Growth was observed at salinities of 0-12 % and at temperatures of 4-41 °C. The isolate was capable of hydrolysing aesculin and Tween 80 and reduction of nitrate to nitrite, but unable to hydrolyse gelatin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II1-22F33T belongs to the family Rhodobacteraceae, with highest sequence similarity to Pseudooceanicola marinus AZO-CT (96.5 %). The principal fatty acids (>10 %) were summed feature 8 (C18 : 1ω7c/ω6c) (73.8 %). The G+C content of the genomic DNA was 66.2 mol%. The respiratory quinone was Q-10 (100 %). Phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC), two unidentified aminolipids (ALs), six unidentified phospholipids (PLs) and one unidentified lipid (L) were present. The combined genotypic and phenotypic data show that strain 22II1-22F33T represents a novel species within a new genus, for which the name Marinibacterium profundimaris gen. nov., sp. nov. is proposed. The type strain of Marinibacterium profundimaris is 22II1-22F33T ( = LMG 27151T = MCCC 1A09326T).

Aestuariivita atlantica sp. nov., isolated from deep-sea sediment.

A novel strain, 22II-S11-z3T, was isolated from the deep-sea sediment of the Atlantic Ocean. The bacterium was aerobic, Gram-staining-negative, oxidase-positive and catalase-negative, oval- to rod-shaped, and non-motile. Growth was observed at salinities of 1-9 % NaCl and temperatures of 10-45 °C. The isolate could hydrolyse aesculin and Tweens 20, 40 and 80, but not gelatin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II-S11-z3T belonged to the genus Aestuariivita, with highest sequence similarity to Aestuariivita boseongensis KCTC 42052T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization values between strain 22II-S11-z3T and A. boseongensis KCTC 42052T were 71.5 % and 20.0 ± 2.3 %, respectively. The G+C content of the chromosomal DNA was 65.5 mol%. The principal fatty acids (>5 %) were summed feature 8 (C18 : 1ω7c/ω6c) (35.2 %), C19 : 0 cyclo ω8c (20.9 %), C16 : 0 (11.8 %), 11-methyl C18 : 1ω7c (11.4 %) and C12 : 1 3-OH (9.4 %). The respiratory quinone was determined to be Q-10. Diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, nine unidentified phospholipids, one unidentified aminolipid and two unidentified lipids were present. The combined genotypic and phenotypic data show that strain 22II-S11-z3T represents a novel species of the genus Aestuariivita, for which the name Aestuariivita atlantica sp. nov. is proposed, with the type strain 22II-S11-z3T ( = KCTC 42276T = MCCC 1A09432T).

Muricauda indica sp. nov., isolated from deep sea water

A taxonomic study was carried out on strain 3PC125-7T, which was isolated from the deep sea water of the Indian Ocean. The bacterium was rod-shaped, non-flagellated, Gram-stain-negative, oxidase- and catalase-positive and strictly aerobic. Optimal growth was observed at 25-37 °C, at pH 7 and in 1-3 % (w/v) NaCl. On the basis of the results of 16S rRNA gene sequence analysis, strain 3PC125-7T represents a member of the genus Muricauda, with the highest sequence similarity to Muricauda olearia CL-SS4T (96.7 %), followed by Muricauda marina H19-56T (96.7 %) and nine other species of the genus Muricauda(93.5-95.8 %). The principal fatty acids of 3PC125-7T were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1G and the sole respiratory quinone was menaquinone-6. The polar lipids comprise phosphatidylethanolamine, six unidentified phospholipids and three unknown lipids. The genomic DNA G+C content of 3PC125-7T was 41.8 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic data obtained in this study, strain 3PC125-7T is considered to represent a novel species in the genus Muricauda, for which the name Muricaudaindica sp. nov. is proposed, with the type strain 3PC125-7T (=MCCC 1A03198T=KCTC 52318T).