Sphingobium aquiterrae sp. nov., a toluene, meta- and para-xylene-degrading bacterium isolated from petroleum hydrocarbon-contaminated groundwater.

A Gram-negative, aerobic, slightly yellow-pigmented bacterium, designated as SKLS-A10T, was isolated from groundwater sample of the 'Siklós' petroleum hydrocarbon contaminated site (Hungary). Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain SKLS-A10T formed a distinct phyletic lineage within the genus Sphingobium. It shared the highest 16S rRNA gene homology with Sphingobium abikonense DSM 23268T (97.29 %), followed by Sphingobium lactosutens DSM 23389T (97.23 %), Sphingobium phenoxybenzoativorans KCTC 42448T (97.16 %) and Sphingobium subterraneum NBRC 109814T (96.74 %). The predominant fatty acids (>5 % of the total) are C18 : 1ω7c, C14 : 0 2-OH, C16 : 1ω7c/iso C15 : 0 2-OH, C17 : 1ω6c and C16 : 0. The major ubiquinone is Q-10. The predominant polyamine is spermidine. The major polar lipids are sphingoglycolipid and diphosphatidylglycerol. The DNA G+C content of strain SKLS-A10T is 65.9 mol%. On the basis of evidence from this taxonomic study using a polyphasic approach, strain SKLS-A10T represents a novel species of the genus Sphingobium for which the name Sphingobiumaquiterrae sp. nov. is proposed. The type strain is SKLS-A10T (=DSM 106441T=NCAIM B. 02634T).

Tributyl phosphate biodegradation to butanol and phosphate and utilization by a novel bacterial isolate, Sphingobium sp. strain RSMS.

A Sphingobium sp. strain isolated from radioactive solid waste management site (RSMS) completely degraded 7.98 g/L of tributyl phosphate (TBP) from TBP containing suspensions in 3 days. It also completely degraded 20 mM dibutyl phosphate (DBP) within 2 days. The strain tolerated high levels of TBP and showed excellent stability with respect to TBP degradation over several repeated subcultures. On solid minimal media or Luria Bertani media supplemented with TBP, the RSMS strain showed a clear zone of TBP degradation around the colony. Gas chromatography and spectrophotometry analyses identified DBP as the intermediate and butanol and phosphate as the products of TBP biodegradation. The RSMS strain utilized both TBP and DBP as the sole source of carbon and phosphorous for its growth. The butanol released was completely utilized by the strain as a carbon source thereby leaving no toxic residue in the medium. Degradation of TBP or DBP was found to be suppressed by high concentration of glucose which also inhibited TBP or DBP dependent growth. The results highlight the potential of Sphingobium sp. strain RSMS for bioremediation of TBP and for further molecular investigation.

Hephaestia caeni gen. nov., sp. nov., a novel member of the family Sphingomonadaceae isolated from activated sludge.

A Gram-staining-negative, rod-shaped and motile bacterium, designated strain ERB1-3(T), was isolated from a laboratory-scale activated sludge system treating coke plant effluent using thiocyanate-supplemented growth medium. Strain ERB1-3(T) was oxidase-positive and weakly catalase-positive. The predominant fatty acids were C18:1ω7c (35.6 %) and C17:1ω6c (29.2%), and the major respiratory quinone was Q-10. Polar lipids were dominated by sphingoglycolipid and phosphatidylglycerol. Major polyamines were spermidine and sym-homospermidine. The G+C content of the genomic DNA of strain ERB1-3(T) was 66.4 mol%. Based on the 16S rRNA gene, strain ERB1-3(T) exhibited the highest sequence similarity values to Sphingomonas sanxanigenens DSM 19645(T) (96.1%), Sphingobium scionense DSM 19371(T) (95.1%) and Stakelama pacifica LMG 24686(T) (94.8%) within the family Sphingomonadaceae. The novel isolate had some unique chemotaxonomic features that differentiated it from these closely related strains, contained much more C17 : 1ω6c, C15 : 0 2-OH, C17:0 and C17:1ω8c fatty acids and possessed diphosphatidylglycerol only in trace amounts. On the basis of the phenotypic, chemotaxonomic and molecular data, strain ERB1-3(T) is considered to represent a novel genus and species, for which the name Hephaestia caeni gen. nov., sp. nov. is proposed. The type strain is ERB1-3(T) ( = DSM 25527(T) = NCAIM B 02511(T)).

Sphingopyxis indica sp. nov., isolated from a high dose point hexachlorocyclohexane (HCH)-contaminated dumpsite.

A Gram-stain-negative, aerobic, non-motile, non-spore-forming, rod-shaped and light-yellow-pigmented bacterium, designated DS15(T), was isolated from a soil sample collected from a hexachlorocyclohexane dumpsite in Lucknow, Uttar Pradesh, India. Strain DS15(T) showed highest 16S rRNA gene sequence similarity to Sphingopyxis panaciterrulae DCY34(T) (98.7%) and Sphingopyxis soli BL03(T) (98.0%). The 16S rRNA gene sequence similarity between strain DS15(T) and species of genus Sphingopyxis with validly published names ranged from 92.5% to 98.7%. The DNA G+C content of strain DS15(T) was 67.5 mol%. The chemotaxonomic markers in strain DS15(T) were consistent with its classification in the genus Sphingopyxis, i.e. Q-10 as the major ubiquinone and summed feature 8 (C18:1ω7c/C18:1ω9c), C17:1ω6c, summed feature 3 (C16:1ω7c/C16:1ω6c), C14:0 2-OH, C15:0 2-OH, C16:0 and C17:1ω8c as the predominant fatty acids. The major polar lipids of strain DS15(T) were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylcholine (PC), phosphatidylglycerol (PG) and sphingoglycolipids (SGL) and spermidine was detected as the major polyamine. Phylogenetic analysis, DNA-DNA hybridization, and chemotaxonomic and phenotypic analysis support the conclusion that strain DS15(T) represents a novel species within the genus Sphingopyxis, for which the name Sphingopyxis indica is proposed. The type strain is DS15(T) (=MTCC 9455(T)=CCM 7542(T)=MCC 2023(T)).

Characterization of polyhydroxyalkanoates (PHAs) biosynthesis by isolated Novosphingobium sp. THA_AIK7 using crude glycerol.

Biodiesel-contaminated wastewater was used to screen for PHAs-producing bacteria by using crude glycerol as the sole carbon source. A gram-negative THA_AIK7 isolate was chosen as a potential PHAs producer. The 16S rRNA phylogeny indicated that THA_AIK7 isolate is a member of Novosphingobium genus which is supported by a bootstrap percentage of 100% with Novosphingobium capsulatum. The 1,487 bp of 16S rRNA gene sequence of THA_AIK7 isolate has been deposited in the GenBank database under the accession number HM031593. Polymer content of 45% cell dry weight was achieved in 72 h with maximum product yield coefficient of 0.29 g PHAs g⁻¹ glycerol. Transmission electron micrograph results exhibited the PHAs granules accumulated inside the bacterial cell. PHAs polymer production in mineral salt media supplemented with 2% (w/v) of crude glycerol at initial pH 7 was extracted by the sodium hypochlorite method. Polymer film spectrographs from Nuclear magnetic resonance displayed a pattern of signal virtually identical to spectra of commercial PHB. Thermal analysis by Differential scanning calorimeter showed a melting temperature at 179°C. Molecular weight analysis by Gel permeation chromatography showed two main peaks of 133,000 and 700 g mol⁻¹ with weight-average molecular weight value of 23,800 and number-average molecular weight value of 755. Endotoxinfree of PHAs polymer was preliminarily assessed by a negative result of the gel-clot formation, Pyrotell® Single test vial, at sensitivity of 0.25 EU ml⁻¹. To our knowledge, this is the first reported test of endotoxin-free PHAs naturally produced from gram-negative bacteria which could be used for biomedical application.

Sphingopyxis panaciterrulae sp. nov., isolated from soil of a ginseng field.

A Gram-negative, rod-shaped, motile bacterium was isolated from the soil of a ginseng field in Daejeon, South Korea, and characterized in order to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequence analysis revealed that strain DCY34(T) belonged to the family Sphingomonadaceae, and the highest degree of sequence similarity was found with Sphingopyxis witflariensis W-50(T) (97.1 %), Sphingopyxis ginsengisoli Gsoil 250(T) (97.0 %), Sphingopyxis chilensis S37(T) (96.9 %), Sphingopyxis macrogoltabida IFO 15033(T) (96.8 %), Sphingopyxis alaskensis RB2256(T) (96.7 %) and Sphingopyxis taejonensis JSS54(T) (96.7 %). Chemotaxonomic data revealed that strain DCY34(T) possessed ubiquinone Q-10 as the predominant respiratory lipoquinone, which is common to members of the genus Sphingopyxis. The predominant fatty acids were C18:1ω7c (27.5 %), summed feature 4 (C16:1ω7c and/or C15 :0 iso 2-OH; 18.6 %), C16:0 (15.6 %) and summed feature 8 (C19:1ω6c and/or unknown 18.864; 15.4 %). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, sphingoglycolipid and an unknown polar lipid. The results of physiological and biochemical tests clearly demonstrated that strain DCY34(T) represented a separate species and supported its affiliation to the genus Sphingopyxis. Based on these data, the new isolate represents a novel species, for which the name Sphingopyxis panaciterrulae sp. nov. is proposed. The type strain is DCY34(T) (=KCTC 22112(T)=JCM 14844(T)).

Sphingopyxis ginsengisoli sp. nov., isolated from soil of a ginseng field in South Korea.

A Gram-negative, aerobic, motile, rod-shaped bacterium (strain Gsoil 250(T)) was isolated from soil of a ginseng field in Pocheon province (South Korea) and was characterized using a polyphasic approach in order to determine its taxonomic position. Comparative analysis of 16S rRNA gene sequences showed that strain Gsoil 250(T) belonged to the family Sphingomonadaceae of the class Alphaproteobacteria, and was related to Sphingopyxis macrogoltabida (98.7 %), Sphingopyxis chilensis (98.2 %), Sphingopyxis alaskensis (97.9 %), Sphingopyxis taejonensis (97.9 %) and Sphingopyxis witflariensis (97.8 %). The phylogenetic distance from any other species with validly published names within the genus Sphingopyxis was greater than 3.8 %. The G+C content of the genomic DNA of strain Gsoil 250(T) was 69.2 mol%. Strain Gsoil 250(T) contained Q-10 as the predominant respiratory lipoquinone and C(18 : 1)omega7c and summed feature 4 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH; 34.6 %) as the major fatty acids. No 3-hydroxy fatty acids were detected. Major polar lipids consisted of sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol and two unknown glycolipids. Phenotypic and chemotaxonomic data supported the affiliation of strain Gsoil 250(T) to the genus Sphingopyxis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain Gsoil 250(T) from the eight recognized Sphingopyxis species. Strain Gsoil 250(T) therefore represents a novel species, for which the name Sphingopyxis ginsengisoli sp. nov. is proposed, with the type strain Gsoil 250(T) (=KCTC 12582(T)=LMG 23390(T)).

Sphingobium olei sp. nov., isolated from oil-contaminated soil.

The taxonomic status of a yellow-coloured bacterial isolate from an oil-contaminated soil sample was determined using a polyphasic taxonomic approach. Comparative analysis of 16S rRNA gene sequences showed that the novel isolate formed a distinct phyletic line within the genus Sphingobium. The generic assignment was confirmed by chemotaxonomic data, which revealed: a fatty acid profile that is characteristic of the genus Sphingobium consisting of straight-chain saturated and unsaturated as well as 2-OH fatty acids; a ubiquinone with ten isoprene units (Q-10) as the predominant respiratory quinone; a polar lipid pattern consisting of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine and sphingoglycolipid, and spermidine as the major polyamine component. Genotypic and phenotypic data show that the new isolate merits classification as a representative of a novel species of the genus Sphingobium, for which the name Sphingobium olei sp. nov. is proposed. The type strain is IMMIB HF-1T (=DSM 18999T=CCUG 54329T).

Sandarakinorhabdus limnophila gen. nov., sp. nov., a novel bacteriochlorophyll a-containing, obligately aerobic bacterium isolated from freshwater lakes.

Three strains (so36, so42T and wo26) representing a novel Gram-negative, obligately aerobic, bacteriochlorophyll a-containing species of the alpha-4 subgroup of the Proteobacteria were isolated from freshwater lakes using a high-throughput cultivation technique. The non-motile and slender rod-shaped cells formed orange-red-pigmented colonies. The main carotenoids were nostoxanthin and keto-nostoxanthin. According to the absorption spectrum, two different photosynthetic light-harvesting complexes, an LHI complex and a B800-830-type peripheral LHII complex, were present in the cells. The predominant fatty acids of strain so42T were hexadecenoic acid (16 : 1omega7c) and octadecenoic acid (18 : 1omega7c), whereas 17 : 1omega6c and 14 : 0 iso 2-OH were present in smaller amounts. The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, glycolipid and sphingoglycolipids. The major respiratory lipoquinone was ubiquinone-10, whereas ubiquinone-9 was present in smaller amounts. The three strains were cytochrome oxidase-negative and catalase-positive and formed alkaline and acid phosphatases. The strains grew chemoorganoheterotrophically in mineral media supplemented with various organic acids, amino acids or complex substrates such as peptone and yeast extract. The G+C content of the genomic DNA of strain so42T was 64.3 mol%. The three novel isolates contained the same 16S rRNA gene sequence. The 16S rRNA gene sequence similarity to the closest phylogenetic relative Sandaracinobacter sibiricus was only 92.8 %. Accordingly, the three strains represent a new genus and species, for which the name Sandarakinorhabdus limnophila gen. nov., sp. nov., is proposed, with strain so42T (=DSM 17366T = CECT 7086T) as the designated type strain.