Novosphingobium cyanobacteriorum sp. nov., isolated from a eutrophic reservoir during the Microcystis bloom period

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain, HBC54T, was isolated from periphyton during a Microcystis bloom. Based on the results of the 16S rRNA gene sequence analysis, strain HBC54T was closely related to Novosphingobium aerophilum 4Y4T (98.36 %), Novosphingobium aromaticivorans DSM 12444T (98.08 %), Novosphingobium huizhouense c7T (97.94 %), Novosphingobium percolationis c1T (97.65 %), Novosphingobium subterraneum DSM 12447T (97.58 %), Novosphingobium olei TW-4T (97.58 %) and Novosphingobium flavum UCT-28T (97.37 %). The average nucleotide identity and digital DNA-DNA hybridization values between HBC54T and its related type stains were below 78.97 and 23.7 %, which are lower than the threshold values for species delineation. The major fatty acids (>10.0 %) were identified as C14 : 0 2-OH, summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c) and summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c) and the respiratory quinone was ubiquinone Q-10. The main polar lipids detected in the strain were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol and three unidentified phospholipids. The genomic DNA G+C content was 64.8 mol%. Strain HBC54T is considered to represent a novel species within the genus Novosphingobium, for which the name Novosphingobium cyanobacteriorum sp. nov. is proposed. The type strain is HBC54T (=KCTC 92033T=LMG 32427T).

Comparative genomic analysis of the genus Novosphingobium and the description of two novel species Novosphingobium aerophilum sp. nov. and Novosphingobium jiangmenense sp. nov

Members of the genus Novosphingobium are well known for their metabolically versatile and great application potential in pollution elimination. The three novel bacterial strains, designated 4Y4^T, 4Y9, and 1Y9A^T, were isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. The 16S rRNA gene sequences phylogenetic analysis revealed that the three strains belonged to the genus Novosphingobium. The phylogenomic analysis indicated that the three strains formed two independent and robust branches distinct from all reference strains. The analyses of dDDH values and ANIs between the three strains and their relatives further demonstrated that the three strains represented two different novel genospecies. Comparative genomic analysis of the three isolates and 32 type strains of the genus Novosphingobium showed that the most important central metabolic pathways of these strains appeared to be similar, while specific and specialized metabolic pathways were flexible and variable among these strains. Chemotaxonomic characterization exhibited that the predominant cellular fatty acids were summed feature 8, summed feature 3, and C_14:0 2OH; the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylglycerol, and sphingoglycolipid; the major respiratory quinone and polyamine were Q-10 and spermidine. The DNA G + C contents were 67.6 and 64.7 %. Based on the genotypic and phenotypic characteristics, strains 4Y4^T and 1Y9A^T are concluded to represent two novel species of the genus Novosphingobium, for which the names Novosphingobium aerophilum sp. nov. (type strain 4Y4^T = GDMCC 1.1828 ^T = KACC 21946 ^T) and Novosphingobium jiangmenense sp. nov. (type strain 1Y9A^T = GDMCC 1.1936 ^T = KACC 22085 ^T) are proposed.

Novosphingobium olei sp. nov., with the ability to degrade diesel oil, isolated from oil-contaminated soil and proposal to reclassify Novosphingobium stygium as a later heterotypic synonym of Novosphingobium aromaticivorans

Two yellow-pigmented, non-motile, Gram-stain-negative, and rod-shaped bacteria, designated TW-4^T and TNP-2 were obtained from oil-contaminated soil. Both strains degrade diesel oil, hydrolyse aesculin, DNA, Tween 40 and Tween 60. A phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain TW-4^T formed a lineage within the family Erythrobacteraceae and clustered as members of the genus Novosphingobium. The closest members of strain TW-4^T were Novosphingobium subterraneum DSM 12447^T (97.9 %, sequence similarity), Novosphingobium lubricantis KSS165-70^T (97.8 %), Novosphingobium taihuense T3-B9^T (97.8 %), Novosphingobium aromaticivorans DSM 12444^T (97.7 %), Novosphingobium flavum UCT-28^T (97.7 %), and Novosphingobium bradum STM-24^T (97.6 %). The sequence similarity for other members was ≤97.6 %. The genome of strain TW-4^T was 4 683 467 bp long with 44 scaffolds and 4280 protein-coding genes. The sole respiratory quinone was Q-10. The major cellular fatty acids were summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c), summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c), C_16 : 0 and C_14 : 0 2-OH. The major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylcholine (PC), phosphatidyl-n-methylethanolamine (PME) and sphingoglycolipid (SGL). The DNA G+C content of the type strain was 65.0 %. The average nucleotide identity (ANIu) and in silico DNA-DNA hybridization (dDDH) relatedness values between strain TW-4^T and closest members were below the threshold value for species delineation. Based on polyphasic taxonomic analyses, strain TW-4^T represents novel species in the genus Novosphingobium, for which the name Novosphingobium olei sp. nov. is proposed. The type strain is TW-4^T (=KACC 21628^T=NBRC 114364^T) and strain TNP-2 (=KACC 21629=NBRC 114365) represents an additional strain. Based on new data obtained in this study, it is also proposed to reclassify Novosphingobium stygium as a later heterotypic synonym of Novosphingobium aromaticivorans.

Novosphingobium ovatum sp. nov., isolated from a freshwater mesocosm

A bacterial strain, designated FSY-8^T, was isolated from a freshwater mesocosm in Taiwan and characterized using the polyphasic taxonomy approach. Cells of strain FSY-8^T were aerobic, Gram-stain-negative, rod-shaped, non-motile and formed yellow coloured colonies on Reasoner's 2A agar. Growth occurred at 20-40 °C (optimum, 30-37 °C) and pH 5-7 (optimum, pH 6) and in the presence of 0-0.5 % NaCl (optimum, 0 %, w/v). The major fatty acids (>10 %) of strain FSY-8^T were summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c) and summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c). The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, sphingoglycolipid, diphosphatidylglycerol, an uncharacterized aminophospholipid, an uncharacterized glycolipid and an uncharacterized lipid. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 64.8 mol %. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain FSY-8^T formed a phylogenetic lineage in the genus Novosphingobium. Strain FSY-8^T showed 71.6-77.2 % average nucleotide identity and 19.9-22.8 % digital DNA-DNA hybridization identity with the strains of other Novosphingobium species. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain FSY-8^T should be classified in a novel species of the genus Novosphingobium, for which the name Novosphingobium ovatum sp. nov. is proposed. The type strain is FSY-8^T (=BCRC 81051^T=LMG 30053^T=KCTC 52812^T).

Novosphingobium umbonatum sp. nov., isolated from a freshwater mesocosm

A bacterial strain designated FSY-9^T was isolated from a freshwater mesocosm in Taiwan and characterized to determine its taxonomic affiliation. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain FSY-9^T formed a phylogenetic lineage in the genus Novosphingobium. Strain FSY-9^T was most closely related to Novosphingobium humi R1-4^T with a 97.2 % 16S rRNA gene sequence similarity. Strain FSY-9^T showed 71.3-72.6 % average nucleotide identity and 17.7-23.0 % digital DNA-DNA hybridization identity with the strains of other Novosphingobium species. Cells of strain FSY-9^T were facultatively anaerobic, Gram-negative, rod-shaped, non-motile and formed light yellow coloured colonies. Growth occurred at 15-37 °C and pH 5.5-7, and in the presence of 0-0.5 % NaCl. The major fatty acids (>10 %) of strain FSY-9^T were summed feature 3 (C_16 : 1ω7c and/or C_16 : 1ω6c), C_18 : 1ω7c and C_16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidyldimethylethanolamine, sphingoglycolipid, an uncharacterized aminophospholipid, an uncharacterized glycolipid and an uncharacterized lipid. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 61.5 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain FSY-9^T should be classified as a novel species of the genus Novosphingobium, for which the name Novosphingobium umbonatum sp. nov. is proposed. The type strain is FSY-9^T (=BCRC 81052^T=LMG 30054^T=KCTC 52813^T).

Novosphingobium guangzhouense sp. nov., with the ability to degrade 1-methylphenanthrene

A novel Gram-stain-negative, flagellated, rod-shaped, yellow-pigmented aerobic bacterium, strain SA925T, that is capable of degrading 1-methylphenanthrene was isolated from oil-polluted soil collected from a refinery located in Guangzhou, China. Phylogenetic analysis based on the 16S rRNA gene sequence demonstrated that strain SA925T belongs to the genus Novosphingobium and is evolutionarily close to the type strains of Novosphingobium gossypii (98.5 % similarity), Novosphingobium panipatense (98.2 %), Novosphingobium mathurense (98.0 %) and Novosphingobium pentaromativorans (96.5 %). The G+C content of the genomic DNA was 60.2 mol%. DNA-DNA hybridization experiments between strain SA925T and the closest strain, Novosphingobium gossypii JM-1396T, revealed a low level of relatedness (35.5 %). Strain SA925T grew at 10-35 °C, at pH 6.0-8.0 and in the presence of 0-4 % (w/v) NaCl. The major fatty acids were C18 : 1ω7c, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipid profiles mainly consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylethanolamine and sphingoglycolipid (the characteristic polar lipid). The predominant ubiquinone was Q-10. The major polyamine was spermidine. Based on the phylogenetic, phenotypic and physiological characteristics, strain SA925T was considered to represent a novel species of the genus Novosphingobium, for which the name Novosphingobium guangzhouense sp. nov. is proposed. The type strain is SA925T (=DSM 32207T=GDMCC 1.1110T).