Major Polyamine Research Articles

Neptunomonas marina sp. nov., isolated from seawater.

Strain HPM-16T, isolated from seawater, was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of an up-to-date bacterial core gene set (92 protein clusters) indicated that strain HPM-16T formed a phylogenetic lineage in the genus Neptunomonas. Strain HPM-16T was most closely related to Neptunomonas concharum LHW37T with 16S rRNA gene sequence similarity of 96.7%. Cells were Gram-stain negative, facultatively anaerobic, motile by means of a single polar flagellum, rod-shaped and formed white colonies. Optimal growth occurred at 30-35°C, pH 6.5-8, and in the presence of 2-5% NaCl. C18:1ω7c and summed feature 3 (C16:1ω7c and/or C16:1ω6c) were the predominant fatty acids. The only isoprenoid quinone was Q-8. The polar lipid profile revealed the presence of phosphatidylethanolamine, phosphatidylglycerol and several uncharacterized lipids. The major polyamines were putrescine and spermidine. The draft genome was approximately 3.68Mb in size with a G + C content of 50.5mol%. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain HPM-16T should be classified as a novel species of the genus Neptunomonas, for which the name Neptunomonas marina sp. nov. is presented. The type strain is HPM-16T (= BCRC 80980T = LMG 29560T = KCTC 52235T).

Sphingomonas lenta sp. nov., a slowly growing bacterium isolated from an abandoned lead-zinc mine.

A novel slowly growing member of the genus Sphingomonas, designated 1PNM-20T, was isolated from an abandoned lead-zinc mine in Meizhou, Guangdong Province, PR China. A polyphasic taxonomic study was performed to characterize the novel strain. Growth occurred on Reasoner's 2A (R2A) agar and peptone-yeast extract (PYE) agar, but not in liquid R2A or PYE media. Cells were Gram-stain-negative, aerobic, non-spore-forming, rod-shaped and motile with a polar flagellum (monotrichous). 16S rRNA gene sequence comparison showed that it shared the highest similarity with Sphingomonas carriPR0302T (97.2 %), followed by Sphingomonas spermidinifaciens 9NM-10T (97.0 %), Sphingomonas floccifaciens FQM01T (97.0 %) and other species of Sphingomonas (<97 %). Phylogenetic analyses clearly showed that strain 1PNM-20T fell into the cluster of Sphingomonas, and was most closely related to S. carri. The draft genome sequence was 3.76 Mb in length with a DNA G+C content of 69.8 mol%. Major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and 11-methyl C18 : 1ω7c, with C14 : 0 2-OH as the main hydroxy fatty acid. Ubiquinone 10 (Q-10) was the predominant respiratory quinone, and sym-homospermidine was displayed as the major polyamine. The polar lipids were composed of sphingoglycolipid, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified phospholipid and an unidentified glycolipid. The phenotypic, phylogenetic and chemotaxonomic results supported the hypothesis that strain 1PNM-20T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas lenta sp. nov. is proposed. The type strain is 1PNM-20T (=GDMCC 1.660T=DSM 27572T).

Involvement of polyamines in sucrose-induced tolerance to atrazine-mediated chemical stress in Arabidopsis thaliana

Treatment of Arabidopsis thaliana seedlings with the PSII-inhibiting herbicide atrazine results in xenobiotic and oxidative stress, developmental arrest, induction of senescence and cell death processes. In contrast, exogenous sucrose supply confers a high level of atrazine stress tolerance, in relation with genome-wide modifications of transcript levels and regulation of genes involved in detoxification, defense and repair. However, the regulation mechanisms related to exogenous sucrose, involved in this sucrose-induced tolerance, are largely unknown. Characterization of these mechanisms was carried out through a combination of transcriptomic, metabolic, functional and mutant analysis under different conditions of atrazine exposure. Exogenous sucrose was found to differentially regulate genes involved in polyamine synthesis. ARGININE DECARBOXYLASE ADC1 and ADC2 paralogues, which encode the rate-limiting enzyme (EC 4.1.1.19) of the first step of polyamine biosynthesis, were strongly upregulated by sucrose treatment in the presence of atrazine. Such regulation occurred concomitantly with significant changes of major polyamines (putrescine, spermidine, spermine). Physiological characterization of a mutant affected in ADC activity and exogenous treatments with sucrose, putrescine, spermidine and spermine further showed that modification of polyamine synthesis and of polyamine levels could play adaptive roles in response to atrazine stress, and that putrescine and spermine had antagonistic effects, especially in the presence of sucrose. This interplay between sucrose, putrescine and spermine is discussed in relation with survival and anti-death mechanisms in the context of chemical stress exposure.

Flavobacterium sufflavum sp. nov., isolated from a freshwater lake.

A bacterial strain, BBQ-12T, was isolated from a freshwater lake in Taiwan. The strain was Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and formed yellow colonies. Optimal growth occurred at 25 °C, pH 6 and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain BBQ-12T formed a phylogenetic lineage in the genus Flavobacterium. Strain BBQ-12T was most closely related to Flavobacterium fluminis 3R17T with 98.1 % 16S rRNA gene sequence similarity. Strain BBQ-12T showed 74.4-83.1 % average nucleotide identity and 16.0-21.8 % digital DNA-DNA hybridization identity with the type strains of other closely related Flavobacterium species. Strain BBQ-12T contained iso-C15 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and anteiso-C15 : 0 as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, four uncharacterized aminophospholipids and three uncharacterized phospholipids. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6. The DNA G+C content of the genomic DNA was 34.2 mol%. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain BBQ-12T should be classified as a novel species of the genus Flavobacterium, for which the name Flavobacteriumsufflavum sp. nov. is proposed. The type strain is BBQ-12T (=BCRC 81049T=LMG 30051T=KCTC 52809T).

Metabolites Involved in Immune Evasion by Batrachochytrium dendrobatidis Include the Polyamine Spermidine.

Amphibians have been declining around the world for more than four decades. One recognized driver of these declines is the chytrid fungus Batrachochytrium dendrobatidis, which causes the disease chytridiomycosis. Amphibians have complex and varied immune defenses against B. dendrobatidis, but the fungus also has a number of counterdefenses. Previously, we identified two small molecules produced by the fungus that inhibit frog lymphocyte proliferation, methylthioadenosine (MTA) and kynurenine (KYN). Here, we report on the isolation and identification of the polyamine spermidine (SPD) as another significant immunomodulatory molecule produced by B. dendrobatidis SPD and its precursor, putrescine (PUT), are the major polyamines detected, and SPD is required for growth. The major pathway of biosynthesis is from ornithine through putrescine to spermidine. An alternative pathway from arginine to agmatine to putrescine appears to be absent. SPD is inhibitory at concentrations of ≥10 μM and is found at concentrations between 1 and 10 μM in active fungal supernatants. Although PUT is detected in the fungal supernatants, it is not inhibitory to lymphocytes even at concentrations as high as 100 μM. Two other related polyamines, norspermidine (NSP) and spermine (SPM), also inhibit amphibian lymphocyte proliferation, but a third polyamine, cadaverine (CAD), does not. A suboptimal (noninhibitory) concentration of MTA (10 μM), a by-product of spermidine synthesis, enhances the inhibition of SPD at 1 and 10 μM. We interpret these results to suggest that B. dendrobatidis produces an "armamentarium" of small molecules that, alone or in concert, may help it to evade clearance by the amphibian immune system.

Flavobacterium piscinae sp. nov., isolated from a fish pond.

Strain ICH-30T was isolated from a freshwater fish pond in Taiwan. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain ICH-30T formed a phylogenetic lineage in the genus Flavobacterium. Strain ICH-30T was most closely related to Flavobacteriumlacus NP180T with 97.0 % 16S rRNA gene sequence similarity. Strain ICH-30T showed 70.0-83.1 % average nucleotide identity and 16.5-23.7 % digital DNA-DNA hybridization identity with the type strains of other closely related Flavobacterium species. Cells of strain ICH-30T were Gram-stain-negative, strictly aerobic, non-motile, rod-shaped and formed dark orange colonies. Optimal growth occurred at 20-30 °C, pH 8-9 and 0-0.5 % NaCl. Strain ICH-30T contained iso-C15 : 1 G and iso-C15 : 0 as the predominant fatty acids. The major hydroxyl fatty acids were iso-C17 : 0 3-OH, iso-C16 : 0 3-OH and iso-C15 : 0 3-OH. The polar lipid profile consisted of phosphatidylethanolamine, six uncharacterized aminophospholipids, one uncharacterized phospholipid and two uncharacterized lipids. The major polyamine was homospermidine. The only isoprenoid quinone was MK-6. The DNA G+C content of the genomic DNA was 34.3 mol%. On the basis of the phylogenetic inference and phenotypic data, strain ICH-30T should be classified as a novel species, for which the name Flavobacterium piscinae sp. nov. is proposed. The type strain is ICH-30T (=BCRC 81122T=LMG 30579T=KCTC 62513T).

Deminuibacter soli gen. nov., sp. nov., isolated from forest soil, and reclassification of Filimonas aurantiibacter as Arvibacter aurantiibacter comb. nov.

A novel strain, designated K23C18032701T, was isolated from a sample of forest soil collected from Dinghushan Biosphere Reserve, Guangdong Province, PR China. The strain was Gram-stain-negative, aerobic, motile and showed a shape change from a filamentous cell to coccobacilli. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the novel strain belongs to the family Chitinophagaceae, and showed the highest similarities to Arvibacter flaviflagrans JCM 31293T (95.0 %) and Filimonas aurantiibacter LMG 29039T (94.4 %). The major cellular fatty acids included iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. The predominant polar lipid was phosphatidylethanolamine (PE). The predominant respiratory quinone was menaquinone-7. The major polyamine was sym-homospermidine. The draft genome size of strain K23C18032701T was 5.84 Mb with a DNA G+C content of 47.2 mol%. Based on phenotypic, genotypic and phylogenetic analysis, strain K23C18032701T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Deminuibacter soli is proposed. The type strain is K23C18032701T (=GDMCC 1.1403T=KCTC 62913T). We also propose the reclassification of Filimonas aurantiibacter as Arvibacter aurantiibacter comb. nov. (type strain 1458T=NRRL B-65305T=LMG 29039T).

Taibaiella helva sp. nov., isolated from farmland soil in China.

A yellow-coloured bacterial strain, designated F-4T, was isolated from a farmland soil sample from Qianshan, Anhui province, China. Strain F-4T was Gram-stain-negative, strictly aerobic, oval-shaped, motile (by gliding) and non-spore-forming. Growth occurred at 20-35 °C (optimum, 30 °C), at pH 6.0-8.0 (pH 7.0) and with 0-1.0 % (w/v) NaCl (0 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain F-4T belonged to the genus Taibaiella. 16S rRNA gene sequence similarity values between strain F-4T and the type strains of the three recognized species of the genus Taibaiella, Taibaiella koreensis KACC 17171T, Taibaiella soli KCTC 42277T and Taibaiella chishuiensis JCM 19637T, were 98.1, 96.4 and 95.9 %, respectively. The predominant respiratory quinone was MK-7, with MK-8 as a minor component. The major polar lipids of strain F-4T were three unidentified lipids, two unidentified aminolipids, three unidentified phospholipids, an unidentified aminophospholipid and phosphatidylethanolamine. The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0. The G+C content of the genomic DNA based on total genome calculations was 51.3 mol%. The major polyamine of strain F-4T was homospermidine. The average nucleotide identity and the digital DNA-DNA hybridization values for draft genomes between strain F-4T and strain THG-DT86T were 79.8 and 22.6 %, respectively. On the basis of the genotypic and phenotypic data presented here, strain F-4T represents a novel species of the genus Taibaiella, for which the name Taibaiella helva sp. nov. is proposed. The type strain is F-4T (=KCTC 62442T=CGMCC 1.13562T).

Spermine Differentially Refines Plant Defense Responses Against Biotic and Abiotic Stresses.

Roles of the major polyamines (mPA), putrescine, spermidine, and spermine (Spm), in various developmental and physiological processes in plants have been well documented. Recently, there has been increasing focus on the link between mPA metabolism and defense response during plant-stress interactions. Empirical evidence is available for a unique role of Spm, distinct from the other mPA, in eliciting an effective defense response to (a)biotic stresses. Our understanding of the precise molecular mechanism(s) by which Spm modulates these defense mechanisms is limited. Further analysis of recent studies indicates that plant Spm functions differently during biotic and abiotic interactions in the regulation of oxidative homeostasis and phytohormone signaling. Here, we summarize and integrate current knowledge about Spm-mediated modulation of plant defense responses to (a)biotic stresses, highlighting the importance of Spm as a potent plant defense activator with broad-spectrum protective effects. A model is proposed to explain how Spm refines defense mechanisms to tailor an optimal resistance response.

Zavarzinia aquatilis sp. nov., isolated from a freshwater river.

A Gram-stain-negative, strictly aerobic, catalase-positive and oxidase-positive bacterium, designated strain HR-AST, was isolated from a water sample of the Han River located in the Republic of Korea. Cells were motile rods with a polar flagellum. Growth was observed at 5-35 °C (optimum of 25 °C) and pH 6-8 (optimum of pH 7) and in the presence of 0-2 % (w/v) NaCl (optimum of 0 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HR-AST formed a tight phylogenic lineage with Zavarzinia compransoris LMG 5821T. Strain HR-AST was most closely related to Z. compransoris LMG 5821T with a 98.7 % 16S rRNA gene sequence similarity and had very low similarities (below 91.0 %) to other type strains with validly published names. Average nucleotide identity and in silico DNA-DNA hybridization values between strain HR-AST and Z. compransoris DSM 1231T were 80.4 and 23.1 %, respectively. Strain HR-AST contained ubiquinone-10 as the major quinone and homospermidine and putrescine as the major polyamines. The major fatty acids were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C16 : 0 and C18 : 1 2-OH. Strain HR-AST contained diphosphatidylglycerol, an unidentified aminolipid and two unidentified phospholipids as major polar lipids. The DNA G+C content of strain HR-AST was 67.2 mol%. Based on the genotypic, chemotaxonomic and phenotypic analyses, strain HR-AST represents a novel species of the genus Zavarzinia, for which the name Zavarziniaaquatilis sp. nov. is proposed. The type strain is HR-AST (=KACC 19412T=JCM 32263T).

Flavobacterium niveum sp. nov., isolated from a freshwater creek.

Strain TAPW14T was isolated from a freshwater creek in Taiwan. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain TAPW14T belonged to the genus Flavobacterium and was most closely related to Flavobacterium akiainvivens IK-1T (96.6 % sequence identity) and Flavobacterium hauense BX12T (96.0 %) and less than 96 % sequence similarity to other members of the genus. Cells of strain TAPW14T were Gram-negative, strictly aerobic, motile by gliding, rod-shaped and formed white colonies. Optimal growth occurred at 20 °C, pH 7 and in the presence of 0.5 % NaCl. Strain TAPW14T contained summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 0 and C16 : 0 as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, three uncharacterized aminophospholipids, one uncharacterized phospholipid and one uncharacterized lipid. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6. The DNA G+C content of the genomic DNA was 46.0 mol%. On the basis of the phylogenetic inference and phenotypic data, strain TAPW14T should be classified as a novel species, for which the name Flavobacteriumniveum sp. nov. is proposed. The type strain is TAPW14T (=BCRC 81055T=LMG 30057T=KCTC 52808T).

Flavobacterium circumlabens sp. nov. and Flavobacterium cupreum sp. nov., two psychrotrophic species isolated from Antarctic environmental samples

A taxonomic study of 24 Gram-stain-negative rod-shaped bacteria originating from the Antarctic environment is described. Phylogenetic analysis using 16S rRNA gene sequencing differentiated isolated strains into two groups belonging to the genus Flavobacterium. Group I (n=20) was closest to Flavobacterium aquidurense WB 1.1-56T (98.3% 16S rRNA gene sequence similarity) while group II (n=4) showed Flavobacterium hydatis DSM 2063T as its nearest neighbour (98.5–98.9% 16S rRNA gene sequence similarity). Despite high 16S rRNA gene sequence similarity, these two groups represented two distinct novel species as shown by phenotypic traits and low genomic relatedness assessed by rep-PCR fingerprinting, DNA-DNA hybridization and whole-genome sequencing. Common to representative strains of both groups were the presence of major menaquinone MK-6 and sym-homospermidine as the major polyamine. Common major fatty acids were C15:0 iso, C15:1 iso G, C15:0 iso 3-OH, C17:0 iso 3OH and Summed Feature 3 (C16:1ω7c/C16:1ω6c). Strain CCM 8828T (group I) contained phosphatidylethanolamine, three unidentified lipids lacking a functional group, three unidentified aminolipids and single unidentified glycolipid in the polar lipid profile. Strain CCM 8825T (group II) contained phosphatidylethanolamine, eight unidentified lipids lacking a functional group, three unidentified aminolipids and two unidentified glycolipids in the polar lipid profile. These characteristics corresponded to characteristics of the genus Flavobacterium. The obtained results showed that the analysed strains represent novel species of the genus Flavobacterium, for which the names Flavobacterium circumlabens sp. nov. (type strain CCM 8828T=P5626T=LMG 30617T) and Flavobacterium cupreum sp. nov. (type strain CCM 8825T=P2683T=LMG 30614T) are proposed.

Sphingosinicella humi sp. nov., isolated from arsenic-contaminated farmland soil and emended description of the genus Sphingosinicella.

A Gram-stain-negative, strictly aerobic bacterium, designated strain QZX222T, was isolated from arsenic-contaminated farmland soil. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain QZX222T was clustered with Sphingosinicella vermicomposti YC7378T (97.0 %), Sphingosinicellaxenopeptidilytica 3-2W4T (96.1 %), Sphingosinicella microcystinivorans Y2T (96.0 %) and Sphingosinicella soli KSL-125T (95.9 %). Compared to strain QZX222T, Spingomonas olgophenolica JCM 12082T and Sphingobium boeckii 469T had 16S rRNA gene similarities of 96.2 and 95.9 %, respectively, but they located in other phylogenetic clusters. DNA-DNA hybridization and genomic ANI values between strain QZX222T and Sphingosinicella vermicomposti DSM 21593T (KCTC 22446T) were 34.8 and 75.0 %, respectively. The genome size of strain QZX222T was 3.0 Mb including 2982 predicted genes. The strain had a DNA G+C content of 65.9 mol%. Strain QZX222T had ubiquinone Q-10 as the major respiratory quinone and homospermidine as the major polyamine. The major fatty acids (>10 %) of strain QZX222T were C17 : 1ω6c, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C17 : 1ω8c. The polar lipids were sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and an unidentified glycolipid. Strain QZX222T could be distinguished from other Sphingosinicella strains based on the results of phylogenetic and genomic analyses, DNA-DNA hybridization, white colour colony, hydrolysis of urea, alkaline phosphatase activity, lack of phosphatidylmonomethylethanolamine, and presence of phosphatidylcholine. Therefore, strain QZX222T represents a novel species of Sphingosinicella, for which the name Sphingosinicellahumi sp. nov. is proposed. The type strain is QZX222T (=KCTC 62519T=CCTCC AB 2018030T).

Sphingobium aromaticivastans sp. nov., a novel aniline- and benzene-degrading, and antimicrobial compound producing bacterium.

A strictly aerobic, orange-pigmented strain was isolated and designated as UCM-25T. This strain is capable of degrading aniline and benzene, while is also producing antimicrobial compounds which inhibit the growth of some common pathogenic microbes. A near full-length 16S rRNA gene sequence revealed similarity to Sphingobium chlorophenolicum NBRC 16172T (98.6%). The level of DNA-DNA hybridization between the new isolate and the related species suggests UCM-25T to be a new species belonging to the genus Sphingobium. The bacterial cells contained phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, three unidentified polar lipids, and an unidentified aminophospholipid. Ubiquinone Q-10 was the major quinone and spermidine was the major polyamine. The G+C content in the DNA of strain UCM-25T was 62.9mol%. Cells contained summed feature 8 (C18:1ω7c and/or C18:1ω6c), summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16:0, and C14:0 2-OH as major fatty acids. Based on the comparison of phenotypic, genotypic, and chemotaxonomic characteristics, strain UCM-25T represents a new member of the genus Sphingobium, for which the name S. aromaticivastans sp. nov. is proposed. The type strain is UCM-25T (=KACC 19288T =DSM 105181T).

Flavobacterium riviphilum sp. nov., isolated from a freshwater creek.

A novel bacterium, designated strain TAPY6T, was isolated from a freshwater creek in Taiwan. The strain was Gram-stain-negative, strictly aerobic, motile-by-gliding, rod-shaped and formed translucent yellow colonies. Optimal growth occurred at 20-30 °C, pH 6 and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain TAPY6T belonged to the genus Flavobacterium and was most closely related to Flavobacterium succinicans LMG 10402T (97.3 % sequence similarity) and Flavobacterium glycines Gm-149T (96.3 %). Strain TAPY6T contained C15 : 0 and iso-C15 : 0 as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, five uncharacterized aminophospholipids, two uncharacterized phospholipids and one uncharacterized aminolipid. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6. The DNA G+C content of the genomic DNA was 39.8 mol%. Phenotypic characteristics of the novel strain also differed from those of the closest related species of the genus Flavobacterium. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain TAPY6T represents a novel species in the genus Flavobacterium, for which the name Flavobacterium riviphilum sp. nov. is proposed. The type strain is TAPY6T (=BCRC 81007T=LMG 29728T=KCTC 52444T).

Analysis of polyamine biosynthetic- and transport ability of human indigenous Bifidobacterium.

Put: putrescine; Spd: spermidine; Spm: spermine; GAM: Gifu anaerobic medium; BHI: brain-heart infusion.

Sphingomonas turrisvirgatae sp. nov., an agar-degrading species isolated from freshwater.

A yellow pigmented and agar-pitting colony was isolated from a water sample obtained from a drainage ditch within a disused system of constructed wetlands. The strain was purified and named MCT13T. This rod-shaped, Gram-negative, oxidase- and catalase-positive, aerobic, non-spore-forming, and non-motile strain formed round colonies and grew optimally at pH 7.5±0.2, at 28-30 °C on LB agar, with 0-0.5 % NaCl. The 16S rRNA gene sequence analysis placed the MCT13T isolate within the Sphingomonas (sensu stricto) cluster. The DNA G+C content was 65.3 %. The only observed ubiquinone was Q10. The major fatty acids included C17 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c. The major polar lipids were sphingoglycolipid, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The major polyamine was spermidine. The 16S rRNA gene phylogenetic analysis performed on the whole sequence, showed the closest relative of MCT13T to be Sphingomonas koreensis (98.52 %); however, there are several genotypic and phenotypic differences between the novel isolate and the type strain JSS26T of S. koreensis. On the basis of these results, strain MCT13T represents a novel species in the genus Sphingomonas, for which the name Sphingomonas turrisvirgatae sp. nov. is proposed. The type strain is MCT13T (=DSM 105457T=BAC RE RSCIC 7T).

Flavobacterium effusum sp. nov., isolated from a freshwater river.

A yellowish-orange-coloured bacterial strain, PSI-22T, was isolated from a freshwater river in Taiwan. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain PSI-22T belonged to the genus Flavobacterium and showed the highest identity with respect to Flavobacterium dispersum MVW-23T (98.0 %), Flavobacterium tistrianum GB 56.1T (97.1 %), Flavobacterium denitrificans ED5T (97.1 %) and Flavobacterium daemonense THG-DJ7T (97.0 %) and less than 97 % to other members of the genus. Cells of strain PSI-22T were Gram-negative, strictly aerobic, motile by gliding and rod-shaped. Optimal growth occurred at 30 °C, pH 6 and in the presence of 0.5 % NaCl. Strain PSI-22T contained iso-C15 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, one uncharacterized aminophospholipid, one uncharacterized aminophosphoglycolipid, two uncharacterized aminolipids, one uncharacterized phospholipid and one uncharacterized lipid. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6 and the DNA G+C content of the genomic DNA was 41.4 mol%. The DNA-DNA hybridization value for strain PSI-22T with F. dispersum BCRC 80978T, F. tistrianum KCTC 42679T, F. denitrificans DSM 15936T and F. daemonense KACC 17651T was less than 30 %. On the basis of the phylogenetic inference and phenotypic data, strain PSI-22T should be classified as a novel species, for which the name Flavobacterium effusum sp. nov. is proposed. The type strain is PSI-22T (=BCRC 80973T=LMG 29553T=KCTC 52233T).

Flavobacterium parvum sp. nov., isolated from soil polluted by sewer water.

A novel Gram-stain-negative, motile by means of gliding, and short rod-shaped bacterium, designated HS916T, was isolated from soil polluted by sewer water in Cheonan-si, South Korea. Growth occurred at 10-35°C (optimum 30°C), pH 6.0-8.0 (optimum pH 7.0), and 0-1% sodium chloride (NaCl, w/v). Based on similarities of 16S rRNA gene sequences, strain HS916T was closely related to members of the genus Flavobacterium, exhibiting the highest sequence similarities with Flavobacterium glycines Gm-149T (96.4%), followed by F. granuli Kw05T (96.3%), F. fluminis 3R17T (96.3%), F. aquicola TMd3a3T (96.2%), and F. nitratireducens N1T (96.2%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HS916T was placed in a monophyletic cluster with F. nitratireducens N1T and F. fluminis 3R17T. The predominant fatty acids (> 5% of the total) of strain HS916T were iso-C15:0, anteiso-C15:0, iso-C15:0 3-OH, C17:1ω6с, C16:0 3-OH, iso-C17:0 3-OH, and summed feature 3 (C16:1ω7с and/or C16:1ω6с). The major polar lipids of the strain comprised phosphatidylethanolamine, unidentified aminolipids, and five unidentified lipids. The predominant respiratory quinone and the major polyamine were menaquinone-6 (MK-6) and symhomospermidine, respectively. The DNA G + C content of strain HS916T was 34.9 mol%. Based on polyphasic analyses, strain HS916T represents a novel species belonging to the genus Flavobacterium, for which the name Flavobacterium parvum sp. nov. is proposed. The type strain is HS916T (= KACC 19448T = JCM 32368T).

Sphingomonas aeria sp. nov., isolated from air.

A Gram-negative, aerobic, non-spore-forming, non-motile, yellow-pigmented and rod-shaped bacterial strain, designated B093034T, was isolated from air at the foot of Xiangshan mountain, located in Beijing, China. Cells of strain B093034T were oxidase-negative and catalase-positive. Growth was observed at 4-41 °C, at pH 4.5-10.0 and at 0-7 % (w/v) NaCl. The isolate contained Q-10 as the predominant isoprenoid quinone, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C16 : 0 and C14 : 02-OH as the major fatty acids, sym-homospermidine as the major polyamine, and sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol, aminolipid, two unidentified phospholipids and three unidentified polar lipids as the polar lipids. The DNA G+C content was 67.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain B093034T grouped with members of the genus Sphingomonas and was closely related to Sphingomonas sanguinis IFO 13937T (96.49 % similarity), Sphingomonas pseudosanguinis G1-2T (96.37 %), Sphingomonas ginsenosidimutansGsoil 1429T (95.99 %) and Sphingomonas endophytica YIM 65583T (95.78 %). On the basis of the polyphasic evidence presented here, strain B093034T represents a novel species of the genus Sphingomonas, for which the name Sphingomonasaeria sp. nov. is proposed. The type strain is B093034T (=CFCC 13949T=LMG 30133T).