Thalassobius aquaeponti sp. nov., an alphaproteobacterium isolated from seawater

A Gram-stain-negative, aerobic, non-motile and rod-shaped or ovoid bacterial strain, GJSW-22^T, which was isolated from seawater at Geoje island in South Korea, was characterized taxonomically. Strain GJSW-22^T was observed to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain GJSW-22^T grouped with the type strains of Thalassobius species, forming a stable cluster with the type strain of Thalassobius aestuarii (bootstrap value of 83.2 %). Strain GJSW-22^T exhibited the highest 16S rRNA gene sequence similarity value (98.0 %) to the type strain of T. aestuarii. It exhibited 16S rRNA gene sequence similarity values of 95.6–96.1 % to the type strains of the other Thalassobius species. Strain GJSW-22^T was found to contain Q-10 as the predominant ubiquinone and C_18:1 ω7c and 11-methyl C_18:1 ω7c as the major fatty acids. The major polar lipids of strain GJSW-22^T were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G + C content of strain GJSW-22^T is 60.3 mol % and its mean DNA–DNA relatedness value with the type strain of T. aestuarii was 23 %. Differential phenotypic properties, together with the phylogenetic and chemotaxonomic data, confirmed that strain GJSW-22^T is distinct from other Thalassobius species. On the basis of the data presented, strain GJSW-22^T is considered to represent a novel species of the genus Thalassobius, for which the name Thalassobius aquaeponti sp. nov. is proposed. The type strain is GJSW-22^T (=KCTC 42115^T = NBRC 110378^T).     

Loktanella aestuariicola sp. nov., an alphaproteobacterium isolated from a tidal flat

A Gram-stain negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, J-TF4^T, which was isolated from a tidal flat in the South Sea of South Korea, was characterized taxonomically. Strain J-TF4^T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in presence of 2.0–3.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain J-TF4^T fell within the clade comprising the type strains of Loktanella species, clustering with the type strains of Loktanella cinnabarina, Loktanella hongkongensis, Loktanella soesokkakensis, Loktanella pyoseonensis and ‘Loktanella variabilis’ showing sequence similarity values of 97.2–98.4 %. The strain exhibited 16S rRNA gene sequence similarity values of 94.1–95.4 % to the type strains of the other Loktanella species. Strain J-TF4^T was found to have Q-10 as the predominant ubiquinone and C_18:1 ω7c as the major fatty acid. The major polar lipids of strain J-TF4^T were identified as phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified glycolipid and an unidentified aminolipid. The DNA G+C content of strain J-TF4^T was determined to be 67.9 mol% and its mean DNA–DNA relatedness values with the type strains of five phylogenetically related Loktanella species were 17.7–23.3 %. Differential phenotypic properties, together with the phylogenetic and genetic data, demonstrate that strain J-TF4^T is separated from other Loktanella species. On the basis of the data presented, strain J-TF4^T is considered to represent a novel species of the genus Loktanella, for which the name Loktanella aestuariicola sp. nov. is proposed. The type strain is J-TF4^T (=KCTC 42135^T=NBRC 110408^T).     

Lentilitoribacter donghaensis gen. nov., sp. nov., a slowly-growing alphaproteobacterium isolated from coastal seawater

A Gram-staining-negative, aerobic, non-spore-forming, non-flagellated and rod- or short rod-shaped bacterial strain, designated BH-4^T, was isolated from coastal seawater in the East Sea, South Korea. Strain BH-4^T grew optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. Strain BH-4^T exhibited the highest 16S rRNA gene sequence similarity value (96.5 %) to Hoeflea phototrophica NCIMB 14078^T. It exhibited 94.2–95.5, 94.7 and 93.8 % sequence similarity values to the type strains of the other Hoeflea species, Ahrensia kielensis and Pseudahrensia aquimaris, respectively. Neighbor-joining, maximum-likelihood and maximum-parsimony phylogenetic trees revealed that strain BH-4^T clustered with the type strains of A. kielensis and P. aquimaris. Strain BH-4^T contained Q-10 as the predominant ubiquinone as shown in the genera Ahrensia, Pseudahrensia and Hoeflea. The fatty acid and polar lipid profiles of strain BH-4^T were distinguished from those of members of the genera Ahrensia, Pseudahrensia and Hoeflea. The DNA G + C content was 49.3 mol%, lower than those of the type strains of P. aquimaris and Hoeflea species. The phylogenetic data, differential chemotaxonomic and other phenotypic properties revealed that strain BH-4^T constitutes a new genus and species within the Alphaproteobacteria, for which the name Lentilitoribacter donghaensis gen. nov., sp. nov., is proposed. The type strain of Lentilitoribacter donghaensis is BH-4^T (=KCTC 32082^T = CCUG 62792^T).     

Pelagicola litorisediminis sp. nov., a novel alphaproteobacterium isolated from tidal flat sediment

A Gram-negative, aerobic, non-motile and rod-shaped or ovoid bacterial strain, designated D1-W8^T, was isolated from a tidal flat on the South Sea in South Korea. Strain D1-W8^T was found to grow optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2.0–3.0 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain D1-W8^T clustered with the type strain of Pelagicola litoralis showing 97.1 % sequence identity. 16S rRNA gene sequences of the type strains of other species exhibited lower similarity values. Strain D1-W8^T was determined to contain Q-10 as the predominant ubiquinone and C_18:1 ω7c as the predominant fatty acid. The major polar lipids of strain D1-W8^T were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain D1-W8^T was determined to be 57.9 mol% and its DNA–DNA relatedness value with the type strain of P. litoralis was 17 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain D1-W8^T is separate from P. litoralis. On the basis of the data presented, strain D1-W8^T is considered to represent a novel species of the genus Pelagicola, for which the name Pelagicola litorisediminis sp. nov. is proposed. The type strain is D1-W8^T (= KCTC 32327^T = CECT 8287^T).     

Roseovarius gaetbuli sp. nov., a novel alphaproteobacterium isolated from a tidal flat sediment

A Gram-negative, aerobic, non-motile and ovoid or rod-shaped bacterial strain, designated YM-20^T, was isolated from a tidal flat of the Yellow Sea in South Korea. Strain YM-20^T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0–3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain YM-20^T clustered consistently with the type strains of ‘Roseovarius marisflavi’ and Roseovarius lutimaris, with which it exhibited 16S rRNA gene sequence similarities of 99.86 and 98.71 %, respectively. Strain YM-20^T was found to contain Q-10 as the predominant ubiquinone and C_18:1 ω7c as the predominant fatty acid. The major polar lipids of strain YM-20^T were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain YM-20^T was determined to be 60.9 mol% and its DNA–DNA relatedness values with the type strains of ‘R. marisflavi’, R. lutimaris and Pelagicola litorisediminis were 53 ± 7.1, 22 ± 5.5 and 13 ± 4.7  %, respectively. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain YM-20^T is separated from ‘R. marisflavi’, R. lutimaris, the other Roseovarius species and P. litorisediminis. On the basis of the data presented, strain YM-20^T is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius gaetbuli sp. nov. is proposed. The type strain is YM-20^T (= KCTC 32428^T = CECT 8370^T).     

Thalassococcus lentus sp. nov., an alphaproteobacterium isolated from seawater of a seaweed farm

A Gram-negative, non-motile and rod- or ovoid-shaped bacterial strain, designated YCS-24^T, was isolated from seawater of a seaweed farm in the South Sea, South Korea. Strain YCS-24^T grew optimally at 25–28 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. Strain YCS-24^T exhibited the highest 16S rRNA gene sequence similarity values of 97.5 and 97.1 % to the type strains of Thalassobius maritimus and Thalassococcus halodurans, respectively. The neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain YCS-24^T clustered with the type strain of T. halodurans. The DNA G+C content of strain YCS-24^T was 58.0 mol% and its DNA–DNA relatedness values with T. halodurans JCM 13833^T and T. maritimus GSW-M6^T were 17 ± 6.2 and 23 ± 9.2 %, respectively. The predominant ubiquinone found in strain YCS-24^T was Q-10 and the predominant fatty acid of strain YCS-24^T was C_18:1 ω7c. The major polar lipids of strain YCS-24^T were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, demonstrated that strain YCS-24^T is distinguished from T. halodurans. On the basis of the data presented, strain YCS-24^T (= KCTC 32084^T = CCUG 62791^T) represents a novel species of the genus Thalassococcus, for which the name Thalassococcus lentus sp. nov. is proposed.     

Aestuariihabitans beolgyonensis gen. nov., sp. nov., a novel alphaproteobacterium isolated from tidal flat sediment

A Gram-negative, non-motile and rod-shaped bacterial strain, designated BB-MW15^T, was isolated from a tidal flat of the southern coast of the Korean peninsula, and its taxonomic position was investigated by using a polyphasic taxonomic approach. Strain BB-MW15^T grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2–3 % (w/v) NaCl. Strain BB-MW15^T exhibited the highest 16S rRNA gene sequence similarity values to the type strains of Marivita byunsanensis (96.8 %), Thalassobius maritimus (96.6 %), Sulfitobacter marinus (96.4 %) and Marinovum algicola (96.3 %). Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain BB-MW15^T forms an independent lineage within the evolutionary radiation encompassed by the Roseobacter clade of the class Alphaproteobacteria. Strain BB-MW15^T contained Q-10 as the predominant ubiquinone and C_18:1 ω7c as the predominant fatty acid. The major polar lipids detected in strain BB-MW15^T were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain BB-MW15^T is 62.7 mol%. Based on phylogenetic, chemotaxonomic and other phenotypic characteristics, strain BB-MW15^T represents a new genus and a new species within Alphaproteobacteria, for which the name Aestuariihabitans beolgyonensis gen. nov., sp. nov. is proposed. The type strain of A. beolgyonensis is BB-MW15^T (= KCTC 32324^T = CCUG 63829^T).     

Ruegeria meonggei sp. nov., an alphaproteobacterium isolated from ascidian Halocynthia roretzi

A Gram-negative, strictly aerobic, non-flagellated and rod-shaped bacterial strain, designated MA-E2-3^T, was isolated from an ascidian (Halocynthia roretzi) collected from the South Sea, South Korea. Strain MA-E2-3^T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0–3.0 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain MA-E2-3^T fell within the clade comprising Ruegeria species, clustering consistently with the type strain of Ruegeria halocynthiae, with which it exhibited 98.2 % sequence similarity. Sequence similarities to the type strains of the other recognized Ruegeria species were 94.7–97.7 %. Strain MA-E2-3^T was found to contain Q-10 as the predominant ubiquinone and C_18:1 ω7c as the predominant fatty acid. The major polar lipids of strain MA-E2-3^T were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain MA-E2-3^T was determined to be 58.0 mol%. Mean DNA–DNA relatedness values between strain MA-E2-3^T and the type strains of four phylogenetically closely related Ruegeria species were in the range of 13–23 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain MA-E2-3^T is separated from other Ruegeria species. On the basis of the data presented, strain MA-E2-3^T (=KCTC 32450^T = CECT 8411^T) represents a novel species of the genus Ruegeria, for which the name Ruegeria meonggei sp. nov. is proposed.     

Oceanicola litoreus sp. nov., an alphaproteobacterium isolated from the seashore sediment

A Gram-negative, non-motile, facultatively aerobic and rod-shaped bacterial strain, designated M-M22^T, was isolated from seashore sediment on the southern coast in Korea, and its taxonomic position was investigated by using a polyphasic approach. Strain M-M22^T was observed to grow optimally at pH 7.0–7.5, at 30 °C and in the presence of 2 % (w/v) NaCl. Neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain M-M22^T fell within the clade comprising the type strains of Oceanicola species, except Oceanicola granulosus. Strain M-M22^T exhibited the highest 16S rRNA gene sequence similarity values (each 95.4 %) to the type strains of Oceanicola batsensis and Oceanicola nitratireducens and 93.9–94.8 % sequence similarity to the type strains of the other Oceanicola species Strain M-M22^T was found to contain Q-10 as the predominant ubiquinone and C_18:1 ω7c as the predominant fatty acid. Major polar lipids were determined to be phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G+C content was determined to be 67.6 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain M-M22^T is distinguished from other Oceanicola species. On the basis of the data presented, strain M-M22^T is considered to represent a novel species of the genus Oceanicola, for which the name Oceanicola litoreus sp. nov. is proposed. The type strain is M-M22^T (= KCTC 32083^T = CCUG 62794^T).     

Halocynthiibacter namhaensis gen. nov., sp. nov., a novel alphaproteobacterium isolated from sea squirt Halocynthia roretzi

A Gram-negative, non-motile and rod-shaped bacterial strain, designated RA2-3^T, was isolated from a sea squirt (Halocynthia roretzi) collected from the South Sea, Korea, and its taxonomic position was investigated by using a polyphasic approach. Strain RA2-3^T was observed to grow optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. Strain RA2-3^T exhibited the highest 16S rRNA gene sequence similarity values to the type strains of Litoreibacter meonggei (95.7 %), Planktotalea frisia (95.6 %), Thalassobius gelatinovorus (95.5 %) and Pelagicola litoralis (95.4 %). A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain RA2-3^T clustered with the type strains of Planktotalea frisia, Pelagicola litoralis, Pacificibacter maritimus and Roseovarius marinus. Strain RA2-3^T was found to contain Q-10 as the predominant ubiquinone and C_18:1 ω7c as the major fatty acid. The major polar lipids detected in strain RA2-3^T were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain RA2-3^T was 52.9 mol%. On the basis of the phylogenetic, chemotaxonomic and phenotypic properties, strain RA2-3^T is considered to represent a new genus and species within the family Rhodobacteraceae, for which the name Halocynthiibacter namhaensis gen. nov., sp. nov. is proposed. The type strain of H. namhaensis is RA2-3^T (=KCTC 32362^T=NBRC 109999^T).     

Roseomonas aestuarii sp. nov., a bacteriochlorophyll-a containing alphaproteobacterium isolated from an estuarine habitat of India

Two strains (JC17^T and JC19a) of orange pigmented bacteria were isolated from an estuarine sample. Cells of both the strains were Gram-negative coccobacilli, non-motile, non-spore forming and strictly aerobic. Chemo-organoheterotrophy was the growth mode for both strains and was possible on a wide range of organic compounds. Strains were non-hemolytic and contained low levels of BChl-a and carotenoids. The fatty acids (>1.0%) comprised C_18:1ω7c, C_16:1ω7c/iso-C_15:02OH, C_16:0, C_16:0 3-OH, C_18:12OH, C_16:1ω5c, and C_19:0 cycloω8c. The genomic DNA G+C content of strain JC17^T was 66.2 mol%. A phylogenetic tree based on 16 S rRNA gene sequence analysis showed that strains JC17^T and JC19a had the highest similarity to members of the genus Roseomonas and were closely related to Roseomonas cervicalis CIP104027^T (96.4%) and Roseomonas ludipueritiae CIP107418^T (96.3%) of the family Acetobacteraceae within the class Alphaproteobacteria. Strains JC17^T and JC19a shared 100% 16 S rRNA gene sequence similarity, were phenotypically (morphological, physiological, biochemical characters) identical and had closely related genomes (85% DDH). Based on polyphasic taxonomic data, strain JC17^T is classified as a novel species of the genus Roseomonas for which the name Roseomonas aestuarii sp. nov. is proposed. The type strain is JC17^T (=CCUG 57456^T =KCTC 22692^T =NBRC105654^T).     

Polyphasic analysis in the description of Sulfitobacter salinus sp. nov., a marine alphaproteobacterium isolated from seawater

Purpose

A polyphasic analysis was performed on a novel bacterium, designated strain KMU-143^T, which was isolated from seawater collected in the Republic of Korea.

Methods

A novel marine bacterium KMU-143^T was analyzed and described using a polyphasic taxonomic method including 16S rRNA gene sequence analysis, DNA–DNA hybridization, and physiological, biochemical, and chemotaxonomic analyses.

Results

Strain KMU-143^T was Gram-stain-negative, strictly aerobic, oval-shaped, non-motile, and chemoorganoheterotrophic. Phylogenetic analysis based on the 16S rRNA gene sequence demonstrated that the novel marine bacterium belongs to the family Rhodobacteraceae, of the class Alphaproteobacteria, and that it possessed the highest (97.1%) sequence similarity with Sulfitobacter pontiacus ChLG 10^T and Sulfitobacter undariae W-BA2^T. DNA–DNA relatedness values between strains KMU-143^T, S. pontiacus JCM 21789^T, and S. undariae KCTC 42200^T were less than 70%. The major isoprenoid quinone of the novel isolate was ubiquinone-10 (Q-10) and the major (> 10%) cellular fatty acids were C16:0 and C18:1 ω7c. The genomic DNA G+C content of strain KMU-143^T was 56.1 mol%. The polar lipid profile of the strain KMU-143^T was found to consist of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, and two unidentified lipids.

Conclusion

Based on the discriminative phylogenetic position and combination of genotypic and phenotypic properties, the strain is considered to represent a new species of the genus Sulfitobacter for which the name Sulfitobacter salinus sp. nov. is proposed. The type strain of S. salinus sp. nov. is KMU-143^T (= KCCM 90322^T = NBRC 113459^T).

     

Geminicoccus roseus gen. nov., sp. nov., an aerobic phototrophic Alphaproteobacterium isolated from a marine aquaculture biofilter

A Gram-negative, strictly aerobic, diplococcoid bacterium (strain D2-3^T) was isolated from the biofilter of a recirculating marine aquaculture system. Phylogenetic analysis of the 16S rRNA gene sequence of D2-3^T indicated that the new organism occupied a novel lineage within the -1 subclass of Proteobacteria and was related to the genera Rhodothalassium, Azospirillum, Craurococcus, Acidiphilium, and Tistrella. The highest sequence similarity (90.8%) of the 16S rRNA gene sequence of D2-3^T was to that of Candidatus “Alysiosphaera europaea”. D2-3^T was mesophilic, heterotrophic, required sea salt, and had a pH optimum of 8.0. Growth in the presence of light resulted in the formation of pink colonies, a 25% increased cell yield, and a slightly increased growth rate. D2-3^T contained carotenoids and low amounts of bacteriochlorophyll a. Membranes of D2-3^T contained b-type cytochromes. The G+C content of the DNA was 60.3±0.1 mol%. Phylogenetic, morphological, physiological, and biochemical analyses demonstrated that D2-3^T represented a new aerobic phototrophic genus, for which the name Geminicoccus roseus gen. nov., sp. nov. is proposed for the type species (D2-3^T=DSM 18922^T=ATCC BAA-1445^T).     

Novosphingobium hassiacum sp. nov., a new species isolated from an aerated sewage pond

The taxonomy of two strains W-51T and W-52 isolated from a wastewater treatment plant was investigated in a polyphasic approach. The yellow pigmented gram-negative organism contained a quinone system with mainly ubiquinone Q-10, and the polar lipid profile contained a sphingoglycolipid suggesting that both strains belonged to the the alpha-4 subclass of the Proteobacteria. The polar lipid profile consisted furthermore of phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylcholine and of minor amounts of phosphatidylglycerol and phosphatidylmonomethylethanolamine. Sequencing of the 16S rRNA gene supported the allocation into the genus Novosphingobium, together with the type strains of N. subterraneum, N. aromaticivorans, N. stygium, and N. capsulatum, showing similarities of 97.3%, 97.0%, 95.7% and 96.2%, respectively. This allocation was supported by the polyamine profile, which consisted mainly of spermidine. The analysis of the fatty acids revealed 2-OH 13:0, 2-OH 14:0 and 2-OH 15:0, with 2-OH 15:0 as predominant hydroxylated fatty acid. W-51T and W-52 were almost identical with respect to their phenotypic including the majority of the chemotaxonomic properties, identical in their 16S rRNA sequences, and showed 86% DNA-DNA similarity. Both strains were able to reduce nitrate and on the basis of further physiological features, a clear differentiation from all other Novosphingobium species was possible. The DNA-DNA similarities of W-51T to the type strains of N. subterraneum, N. aromaticivorans, and N. capsulatum were below 56%. For these reasons, it is proposed to create a new species with the name Novosphingobium hassiacum sp. nov.