Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sphingomonas”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed2001

Proposal of Sphingomonas wittichii sp. nov. for strain RW1T, known as a dibenzo-p-dioxin metabolizer.

A polyphasic taxonomic study was performed on Sphingomonas sp. strain RW1T. The organism was isolated from water of the River Elbe and has been known as a potent metabolizer of dibenzo-p-dioxin and its relatives. TLC of a mild alkaline hydrolysate of extractable cellular lipids of strain RW1T and type strains of 21 Sphingomonas species gave a spot of sphingoglycolipid (SGL)-1 (glucuronosyl ceramide), which is characteristic of sphingomonads. In addition, strain RW1T and type strains of three Sphingomonas species (Sphingomonas yanoikuyae, Sphingomonas terrae and Sphingomonas macrogoltabidus) showed a second spot of SGL (SGL-1') identified as galacturonosyl ceramide. The presence of SGL-1 in cellular lipids suggested that strain RW1T is a member of the genus Sphingomonas. DNA-DNA reassociation rates between strain RW1T and each type strain of 14 Sphingomonas species including Sphingomonas paucimobilis, type species for the genus, revealed that strain RW1T is independent from these species. Results of phylogenetic analysis of 16S rDNA sequences of strain RW1T and type strains of 21 named Sphingomonas species verified that strain RW1T belongs to the genus Sphingomonas. Strain RW1T could be differentiated from named species of the genus by phenotypic characteristics and has been assigned to a new species, Sphingomonas wittichii sp. nov. The type strain is DSM 6014T (= JCM 10273T = EY 4224T). DNA G+C content is 67 mol %.

Bacterial Typing Techniques↗
PubMed2004

Streptomycin as a selective agent to facilitate recovery and isolation of introduced and indigenous Sphingomonas from environmental samples.

Sphingomonas is an organism of major interest for the degradation of organic contaminants in soils and other environments. A medium based on the aminoglycoside antibiotic streptomycin (Sm) was developed, which, together with the yellow pigmentation of Sphingomonas, facilitated the detection, recovery and quantification of culturable Sphingomonas from soils. All 29 previously described bacterial strains belonging to 17 different Sphingomonas species were able to grow on mineral media containing 200 microg ml(-1) streptomycin, showing that the capacity to resist high concentrations of Sm is a common characteristic within Sphingomonas. Incorporation of Sm into the mineral medium led to a significant reduction in the background microbial population and a concomitant 100 times more sensitive detection of Sphingomonas inoculated in non-sterile soil matrices. The Sm-containing medium was used to examine a variety of hydrocarbon-contaminated soils for the presence and biodiversity of Sphingomonas. Incorporation of Sm in the medium led to a significant increase in the number of yellow-pigmented colonies. Comparison of contaminated and non-contaminated soils derived from the same site revealed colonization by culturable yellow-pigmented Sm-resistant bacteria of the polluted location solely. Both yellow and non-yellow-pigmented colonies were purified from plates containing glucose and Sm, and BOX-polymerase chain reaction (PCR) was used to sort out clonally related strains. Representative strains from the major BOX-PCR clusters were identified using FAME and partial 16S rRNA gene sequencing. Forty-eight of 58 Sm-resistant isolates were identified as Sphingomonas sp. Streptomycin-resistant Sphingomonas isolates generated BOX-PCR diversity patterns that were site dependent and represented different species mainly belonging to Sphingomonas subgroups containing species formerly designated as Sphingopyxis and Sphingobium. The ability to degrade phenanthrene was only found in a minority of the Sphingomonas isolates, which all originated from soils containing high phenanthrene concentrations.

Anti-Bacterial Agents↗
PubMed2004

Occurrence and phylogenetic diversity of Sphingomonas strains in soils contaminated with polycyclic aromatic hydrocarbons.

Bacterial strains of the genus Sphingomonas are often isolated from contaminated soils for their ability to use polycyclic aromatic hydrocarbons (PAH) as the sole source of carbon and energy. The direct detection of Sphingomonas strains in contaminated soils, either indigenous or inoculated, is, as such, of interest for bioremediation purposes. In this study, a culture-independent PCR-based detection method using specific primers targeting the Sphingomonas 16S rRNA gene combined with denaturing gradient gel electrophoresis (DGGE) was developed to assess Sphingomonas diversity in PAH-contaminated soils. PCR using the new primer pair on a set of template DNAs of different bacterial genera showed that the method was selective for bacteria belonging to the family Sphingomonadaceae.Single-band DGGE profiles were obtained for most Sphingomonas strains tested. Strains belonging to the same species had identical DGGE fingerprints, and in most cases, these fingerprints were typical for one species. Inoculated strains could be detected at a cell concentration of 10(4) CFU g of soil(-1). The analysis of Sphingomonas population structures of several PAH-contaminated soils by the new PCR-DGGE method revealed that soils containing the highest phenanthrene concentrations showed the lowest Sphingomonas diversity. Sequence analysis of cloned PCR products amplified from soil DNA revealed new 16S rRNA gene Sphingomonas sequences significantly different from sequences from known cultivated isolates (i.e., sequences from environmental clones grouped phylogenetically with other environmental clone sequences available on the web and that possibly originated from several potential new species). In conclusion, the newly designed Sphingomonas-specific PCR-DGGE detection technique successfully analyzed the Sphingomonas communities from polluted soils at the species level and revealed different Sphingomonas members not previously detected by culture-dependent detection techniques.

Base Sequence↗
PubMed2002

Emendation of the genus Sphingomonas Yabuuchi et al. 1990 and junior objective synonymy of the species of three genera, Sphingobium, Novosphingobium and Sphingopyxis, in conjunction with Blastomonas ursincola.

The 16S rDNA sequence similarities between the type strains of Sphingomonas paucimobilis and 32 other Sphingomonas species range from 90.2 to 99.6%. It might be possible to divide the genus into several new genera according to a dendrogram drawn from 16S rDNA sequence similarity. However, the phenotypic and biochemical information needed to define clusters of strains representing distinct genera within this group of organisms was not previously available. Although the cellular lipids of type strains of all 28 Sphingomonas species tested contained glucuronosyl-(1 --> 1)-ceramide together with 2-hydroxymyristic acid, other molecular species of sphingoglycolipids were distributed randomly. Sphingomonas natatoria and Sphingomonas ursincola, bacteriochlorophyll a-containing, gram-negative facultative phototrophs, belong to the cluster of the genus Sphingomonas. Other phototrophic Porphyrobacter and Erythrobacter species in the Sphingomonadaceae were classified into a cluster different from the genus Sphingomonas, as reported previously. None of the physiological and biochemical characteristics considered, including cellular lipids and fatty acid composition, provided evidence for the division of the current genus Sphingomonas. It is therefore concluded that the genus Sphingomonas should remain undivided at this time. The species of three recently proposed genera, Sphingobium, Novosphingobium and Sphingopyxis, in conjunction with Blastobacter ursincola, are junior objective synonyms of species of the genus Sphingomonas.

Alphaproteobacteria↗
PubMed2004

Detection and characterization of conjugative degradative plasmids in xenobiotic-degrading Sphingomonas strains.

A systematic survey for the presence of plasmids in 17 different xenobiotic-degrading Sphingomonas strains was performed. In almost all analyzed strains, two to five plasmids with sizes of about 50 to 500 kb were detected by using pulsed-field gel electrophoresis. A comparison of plasmid preparations untreated or treated with S1 nuclease suggested that, in general, Sphingomonas plasmids are circular. Hybridization experiments with labeled gene probes suggested that large plasmids are involved in the degradation of dibenzo-p-dioxin, dibenzofuran, and naphthalenesulfonates in S. wittichii RW1, Sphingomonas sp. HH69, and S. xenophaga BN6, respectively. The plasmids which are responsible for the degradation of naphthalene, biphenyl, and toluene by S. aromaticivorans F199 (pNL1) and of naphthalenesulfonates by S. xenophaga BN6 (pBN6) were site-specifically labeled with a kanamycin resistance cassette. The conjugative transfer of these labeled plasmids was attempted with various bacterial strains as putative recipient strains. Thus, a conjugative transfer of plasmid pBN6 from S. xenophaga BN6 to a cured mutant of strain BN6 and to Sphingomonas sp. SS3 was observed. The conjugation experiments with plasmid pNL1 suggested a broader host range of this plasmid, because it was transferred without any obvious structural changes to S. yanoikuyae B1, Sphingomonas sp. SS3, and S. herbicidovorans. In contrast, major plasmid rearrangements were observed in the transconjugants after the transfer of plasmid pNL1 to Sphingomonas sp. HH69 and of pBN6 to Sphingomonas sp. SS3. No indications for the transfer of a Sphingomonas plasmid to bacteria outside of the Sphingomonadaceae were obtained.

Biodegradation, Environmental↗
PubMed2006

Comparison of mineralization of solid-sorbed phenanthrene by polycyclic aromatic hydrocarbon (PAH)-degrading Mycobacterium spp. and Sphingomonas spp.

The mineralization of 14C-phenanthrene, sorbed to porous synthetic amberlite sorbents, i.e., IRC50, XAD7-HP, and XAD2, by three phenanthrene-degrading Mycobacterium soil isolates, i.e., strains VM552, VM531, and VM451 and three phenanthrene-degrading Sphingomonas soil isolates, i.e., strains LH162, EPA505 and LH227, was compared. In P-buffer and in the presence of IRC50, for all strains the maximum rate of mineralization of 14C-phenanthrene was significantly higher (1.1-1.9 ng ml(-1) h(-1)) than the initial abiotic desorption rate (0.2 ng ml(-1) h(-1)), indicating that both Mycobacterium and Sphingomonas utilize sorbed phenanthrene with a higher rate than can be explained by abiotic desorption. Because all Mycobacterium and Sphingomonas strains belonged to different species, it can be suggested that this feature is intrinsic to those genera rather than a specific feature of a particular strain. The final mineralization extent in P-buffer in the presence of IRC50 was about a factor of two higher for the Mycobacterium strains compared to the Sphingomonas strains. Moreover, a significantly higher normalized phenanthrene mineralization ratio in the presence of IRC50 to the control (without IRC50) was found for the Mycobacterium strains compared to the normalized ratio found for the Sphingomonas strains. Addition of minimal nutrients had a more beneficial effect on phenanthrene mineralization by Sphingomonas compared to Mycobacterium, resulting into similar mineralization extents and rates for both types of strains in the presence of IRC50. Our results show that Mycobacterium is better adapted to utilization of sorbed phenanthrene compared to Sphingomonas, especially in nutrient-poor conditions.

Biodegradation, Environmental↗
PubMed2004

Sphingomonas yabuuchiae sp. nov. and Brevundimonas nasdae sp. nov., isolated from the Russian space laboratory Mir.

On the basis of phenotypic and genotypic characteristics and 16S rRNA gene sequence analysis, novel species belonging to the genera Sphingomonas and Brevundimonas were identified from samples taken from the Russian space laboratory Mir. Strain A1-18(T) was isolated from the air. 16S rDNA sequence analysis showed that strain A1-18(T) formed a coherent cluster with Sphingomonas sanguinis, Sphingomonas parapaucimobilis, Sphingomonas paucimobilis and Sphingomonas roseiflava with sequence similarity of 97.5-98.6 %. Similar to other Sphingomonas species, the G+C content was 66.1 mol%, but DNA-DNA hybridization rates at optimal temperatures among these related species were only 24.7-51.7 %. Strain A1-18(T) can be differentiated biochemically from related species. Strain W1-2B(T) was isolated from condensation water. It forms a distinct lineage within the genus Brevundimonas, forming a coherent cluster with Brevundimonas vesicularis, Brevundimonas aurantiaca and Brevundimonas intermedia. 16S rDNA sequence similarities were 98.6-99.5 % and the G+C content was 66.5 mol%, similar to other Brevundimonas species, but DNA-DNA relatedness was only 50.2-54.8 %. Strain W1-2B(T) also showed some differential biochemical properties from its related species. A series of polyphasic taxonomic studies led to the proposal of two novel species, Sphingomonas yabuuchiae sp. nov. (type strain A1-18(T)=GTC 868(T)=JCM 11416(T)=DSM 14562(T)) and Brevundimonas nasdae sp. nov. (type strain W1-2B(T)=GTC 1043(T)=JCM 11415(T)=DSM 14572(T)).

Air Microbiology↗
PubMed2006

Sphingomonas soli sp. nov., a beta-glucosidase-producing bacterium in the family Sphingomonadaceae in the alpha-4 subgroup of the Proteobacteria.

Strain T5-04T, a Gram-negative, non-spore-forming, rod-shaped bacterium, was isolated from soil of a ginseng field in South Korea and characterized in order to determine its taxonomic position. 16S rRNA gene sequence analysis revealed that strain T5-04T belongs to the alpha-4 subgroup of the Proteobacteria, and the highest degrees of sequence similarity determined were to Sphingomonas asaccharolytica IFO 10564T (97.5 %), Sphingomonas koreensis JSS26T (97.1 %), Sphingomonas mali IFO 15500T (96.7 %) and Sphingomonas pruni IFO 15498(T) (96.6 %). Chemotaxonomic data revealed that strain T5-04T possesses ubiquinone Q-10 predominantly, C(18 : 1) as the predominant fatty acid and sphingoglycolipids, all of which corroborate its assignment to the genus Sphingomonas. The results of DNA-DNA hybridization and physiological and biochemical tests clearly demonstrated that strain T5-04T represents a distinct species. Based on polyphasic evidence, T5-04T (=KCTC 12210T = NBRC 100801T = IAM 15213T) should be classified as the type strain of a novel Sphingomonas species, for which the name Sphingomonas soli sp. nov. is proposed.

Molecular Sequence Data↗
PubMed2000

A novel sphingoglycolipid containing galacturonic acid and 2-hydroxy fatty acid in cellular lipids of Sphingomonas yanoikuyae.

A novel sphingoglycolipid was isolated from Sphingomonas yanoikuyae, and its structure was identified as a galacturonosyl-beta (1-->1)-ceramide. This was a characteristic sphingoglycolipid present in S. yanoikuyae and certain other species of Sphingomonas, such as Sphingomonas mali, Sphingomonas terrae, and Sphingomonas macrogoltabidus, but not in the type species of Sphingomonas, Sphingomonas paucimobilis.

Carbohydrates↗
PubMed1999

Detection of Sphingomonas spp in soil by PCR and sphingolipid biomarker analysis.

Sphingomonas spp possess unique abilities to degrade refractory contaminants and are found ubiquitously in the environment. We developed Sphingomonas genus-specific PCR primers (SPf-190 and SPr1-852) which showed specific amplification of a 627-bp 16S rDNA fragment from Sphingomonas spp. A PCR assay using these Sphingomonas specific primers was developed to detect Sphingomonas aromaticivorans B0695R in three texturally distinct soil types, showing detection limits between 1.3-2.2 x 10(3) CFU g(-1) dry soil. A sphingolipid extraction protocol was also developed to monitor Sphingomonas populations in soil quantitatively. The detection limit of the assay was 20 pmol g(-1) dry soil, equivalent to about 3 x 10(5) cells g(-1) dry soil. Survival of S. aromaticivorans B0695R was monitored in the three different soils by antibiotic selective plate counting, PCR and sphingolipid analysis. All three approaches showed that the B0695R cells persisted in the low biomass Sequatchie sub-soil at about 3-5 x 10(7)cells g(-1) dry soil. In comparison to the plate counting assay, both the PCR and sphingolipid analysis detected a significantly higher level of B0695R cells in the clay soil and Sequatchie top-soil, indicating the possibility of the presence of viable but non-culturable B0695R cells in the soils. The combination of PCR and sphingolipid analysis may provide a more realistic estimation of Sphingomonas population in the environment.

Journal Article↗
PubMed2004

Sphingomonas oligophenolica sp. nov., a halo- and organo-sensitive oligotrophic bacterium from paddy soil that degrades phenolic acids at low concentrations.

The taxonomic position of a halo- and organo-sensitive, oligotrophic soil bacterium, strain S213(T), was investigated. Cells were Gram-negative, non-motile, strictly aerobic, yellow-pigmented rods of short to medium length on diluted nutrient broth. When 0.1-0.4 % (w/v) NaCl was added to diluted media composed of peptone and meat extract, growth was inhibited with increasing NaCl concentration and the cells became long aberrant forms. When 6 mM CaCl(2) was added, the cells grew quite normally and aberrant cells were no longer found at 0.1-0.5 % (w/v) NaCl. Chemotaxonomically, strain S213(T) contains chemical markers that indicate its assignment to the Sphingomonadaceae: the presence of ubiquinone Q-10 as the predominant respiratory quinone, C(18 : 1) and C(16 : 0) as major fatty acids, C(14 : 0) 2-OH as the major 2-hydroxy fatty acid and sphingoglycolipids. 16S rRNA gene sequence analysis indicated that strain S213(T) belongs to the genus Sphingomonas, exhibiting high sequence similarity to the 16S rRNA gene sequences of Sphingomonas mali IFO 15500(T) (98.3 %), Sphingomonas pruni IFO 15498(T) (98.0 %), Sphingomonas asaccharolytica IFO 15499(T) (97.9 %) and Sphingomonas echinoides DSM 1805(T) (97.8 %). The results of DNA-DNA hybridization experiments and its phenotypic characteristics clearly distinguished the strain from its nearest neighbours and demonstrate that strain S213(T) represents a novel Sphingomonas species, for which the name Sphingomonas oligophenolica sp. nov. is proposed. The type strain is S213(T) (=JCM 12082(T)=CIP 107926(T)).

Aerobiosis↗
PubMed2002

Sphingomonas melonis sp. nov., a novel pathogen that causes brown spots on yellow Spanish melon fruits.

A polyphasic taxonomic study was performed on the phytopathogenic bacterial strains DAPP-PG 224(T) and DAPP-PG 228, which cause brown spot on yellow Spanish melon (Cucumis melo var. inodorus) fruits. Based on the presence of glucuronosyl ceramide (SGL-1) in cellular lipids, the results of fatty acid analysis and 16S rDNA sequence comparison, the strains had been identified as belonging to the genus Sphingomonas and as phylogenetically related to Sphingomonas mali, Sphingomonas pruni and Sphingomonas asaccharolytica. The levels of 16S rDNA sequence similarity of these three species to strain DAPP-PG 224(T) were respectively 98.0, 98.0 and 97.4%. DNA-DNA hybridization experiments between strains pathogenic on melon fruit and S. mali, S. pruni and S. asaccharolytica revealed < or = 16% relatedness. Based on these results, the two isolates studied are regarded as independent from the type strains of the three species mentioned above. Sphingomonas strains from melon fruits are recognized as forming a genetically and phenotypically discrete species and to be differentiated by phenotypic characteristics from all 29 named species of the genus. Thus, the name Sphingomonas melonis sp. nov. is proposed for the isolates from diseased melon fruits. The type strain is DAPP-PG 224(T) (= LMG 19484(T) = DSM 14444(T)). The G+C content of DNA of the type strain is 65.0 mol%.

Cucumis melo↗
PubMed2004

Sphingomonas phyllosphaerae sp. nov., from the phyllosphere of Acacia caven in Argentina.

Two bacterial strains (FA1 and FA2(T)) were isolated from the phyllosphere of a leguminous tree, Acacia caven, in central Argentina. The strains were Gram-negative, strictly aerobic, rod-shaped, motile and formed yellow-pigmented colonies on nutrient agar. The two-primer RAPD patterns of the two strains were identical, suggesting that they belong to the same species. The complete 16S rRNA gene sequences of the two strains were obtained and comparisons demonstrated that they cluster phylogenetically with the species of the genus Sphingomonas sensu stricto. Strain FA2(T) was most closely related (97.6 %) to Sphingomonas adhaesiva. 16S rRNA gene sequence similarities to all other established Sphingomonas species ranged from 94.4 % (to Sphingomonas echinoides) to 97.6 % (to S. adhaesiva). Strains FA1 and FA2(T) were catalase-positive and oxidase-negative. Aesculin was hydrolysed, gelatin and urea were not. beta-Galactosidase was produced. From 51 compounds tested 21 were used as single sources of carbon. The major respiratory lipoquinone was ubiquinone-10. The predominant cellular fatty acids were 16 : 0, 18 : 1omega7c and 16 : 1omega7c (from summed feature 3). Hydroxy fatty acids 14 : 0 2-OH and 15 : 0 iso 2-OH were present as well (from summed feature 4). The polar lipids detected in strain FA2(T) were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and two unidentified phospholipids. The DNA G+C content of strain FA2(T) was 61 mol%. DNA-DNA hybridization experiments showed 27.6 % relatedness between strain FA2(T) and S. adhaesiva DSM 7418(T). Based upon phenotypic and molecular evidence, a novel species of the genus Sphingomonas is proposed, Sphingomonas phyllosphaerae sp. nov., with strain FA2(T) (=LMG 21958(T)=CECT 5832(T)) as the type strain.

Acacia↗
PubMed2006

Sphingomonas dokdonensis sp. nov., isolated from soil.

A Gram-negative, rod-shaped, Sphingomonas-like bacterial strain, DS-4(T), was isolated from soil of Dokdo, Korea, and its taxonomic position was investigated using a polyphasic approach. Strain DS-4(T) grew optimally on trypticase soy agar medium without NaCl at pH 6.0-6.5 and 25 degrees C. It contained Q-10 as the predominant ubiquinone and C(18 : 1)omega7c, C(16 : 0), C(14 : 0) 2-OH and C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH as the major fatty acids. Sphingoglycolipid, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and unidentified phospholipid were the major polar lipids. The DNA G+C content was 66.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-4(T) fell within the evolutionary radiation comprising Sphingomonas species. Levels of 16S rRNA gene sequence similarity between strain DS-4(T) and the type strains of Sphingomonas species ranged from 93.0 to 97.6 %. DNA-DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain DS-4(T) differs from the recognized Sphingomonas species. On the basis of phenotypic, phylogenetic and genetic data, this strain represents a novel species of the genus Sphingomonas, for which the name Sphingomonas dokdonensis sp. nov. is proposed, with DS-4(T) (=KCTC 12541(T)=CIP 108841(T)) as the type strain.

Bacterial Typing Techniques↗
PubMed2000

Evaluation of fluorescently labeled lectins for noninvasive localization of extracellular polymeric substances in Sphingomonas biofilms.

Three strains of Sphingomonas were grown as biofilms and tested for binding of five fluorescently labeled lectins (Con A-type IV-TRITC or -Cy5, Pha-E-TRITC, PNA-TRITC, UEA 1-TRITC, and WGA-Texas red). Only ConA and WGA were significantly bound by the biofilms. Binding of the five lectins to artificial biofilms made of the commercially available Sphingomonas extracellular polysaccharides was similar to binding to living biofilms. Staining of the living and artificial biofilms by ConA might be explained as binding of the lectin to the terminal mannosyl and terminal glucosyl residues in the polysaccharides secreted by Sphingomonas as well as to the terminal mannosyl residue in glycosphingolipids. Staining of the biofilms by WGA could only be explained as binding to the Sphingomonas glycosphingolipid membrane, binding to the cell wall, or nonspecific binding. Glycoconjugation of ConA and WGA with the target sugars glucose and N-acetylglucosamine, respectively, was used as a method for evaluation of the specificity of the lectins towards Sphingomonas biofilms and Sphingomonas polysaccharides. Our results show that the binding of lectins to biofilms does not necessarily prove the presence of specific target sugars in the extracellular polymeric substances (EPS) in biofilms. The lectins may bind to non-EPS targets or adhere nonspecifically to components of the biofilm matrix.

Biofilms↗
PubMed2002

Growth in coculture stimulates metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2.

Metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2 was significantly enhanced when the strain was grown in coculture with a soil bacterium (designated strain SRS1). Both members of this consortium were isolated from a highly enriched isoproturon-degrading culture derived from an agricultural soil previously treated regularly with the herbicide. Based on analysis of the 16S rRNA gene, strain SRS1 was assigned to the beta-subdivision of the proteobacteria and probably represents a new genus. Strain SRS1 was unable to degrade either isoproturon or its known metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, or 4-isopropyl-aniline. Pure culture studies indicate that Sphingomonas sp. SRS2 is auxotrophic and requires components supplied by association with other soil bacteria. A specific mixture of amino acids appeared to meet these requirements, and it was shown that methionine was essential for Sphingomonas sp. SRS2. This suggests that strain SRS1 supplies amino acids to Sphingomonas sp. SRS2, thereby leading to rapid metabolism of (14)C-labeled isoproturon to (14)CO(2) and corresponding growth of strain SRS2. Proliferation of strain SRS1 suggests that isoproturon metabolism by Sphingomonas sp. SRS2 provides unknown metabolites or cell debris that supports growth of strain SRS1. The role of strain SRS1 in the consortium was not ubiquitous among soil bacteria; however, the indigenous soil microflora and some strains from culture collections also stimulate isoproturon metabolism by Sphingomonas sp. strain SRS2 to a similar extent.

Herbicides↗
PubMed1993

Classification of Rhizomonas suberifaciens, an unnamed Rhizomonas species, and Sphingomonas spp. in rRNA superfamily IV.

Thermal melting profiles of hybrids between 3H-labeled rRNA of Rhizomonas suberifaciens, the causal agent of corky root of lettuce, and chromosomal DNAs from 27 species of gram-negative bacteria indicated that the genus Rhizomonas belongs to superfamily IV of De Ley. On the basis of the melting temperatures of DNA hybrids with rRNAs from the type strains of R. suberifaciens, Sphingomonas paucimobilis, and Sphingomonas capsulata, Rhizomonas strains constitute a separate branch in superfamily IV, which is closely related to but separate from branches containing Zymomonas mobilis, Sphingomonas spp., and S. capsulata. Sphingomonas yanoikuyae and Rhizomonas sp. strain WI4 are located toward the base of the Rhizomonas rRNA branch. DNA-DNA hybridization indicated that S. yanoikuyae is equidistant from Rhizomonas sp. strain WI4 and S. paucimobilis. Sequences of 270 bp of 16S ribosomal DNAs from eight strains of Rhizomonas spp., eight strains of Sphingomonas spp., and Agrobacterium tumefaciens indicated that S. yanoikuyae and Rhizomonas sp. strains WI4 and CA16 are genetically more closely related to R. suberifaciens than to Sphingomonas spp. Thus, S. yanoikuyae may need to be transferred to the genus Rhizomonas on the basis of the results of further study.

Base Sequence↗
PubMed2000

Characterization of Sphingomonas isolates from Finnish and Swedish drinking water distribution systems.

Sphingomonas species were commonly isolated from biofilms in drinking water distribution systems in Finland (three water meters) and Sweden (five water taps in different buildings). The Sphingomonas isolates (n = 38) were characterized by chemotaxonomic, physiological and phylogenetic methods. Fifteen isolates were designated to species Sphingomonas aromaticivorans, seven isolates to S. subterranea, two isolates to S. xenophaga and one isolate to S. stygia. Thirteen isolates represented one or more new species of Sphingomonas. Thirty-three isolates out of 38 grew at 5 degrees C on trypticase soy broth agar (TSBA) and may therefore proliferate in the Nordic drinking water pipeline where the temperature typically ranges from 2 to 12 degrees C. Thirty-three isolates out of 38 grew at 37 degrees C on TSBA and 15 isolates also grew on blood agar at 37 degrees C. Considering the potentially pathogenic features of sphingomonas, their presence in drinking water distribution systems may not be desirable.

Drinking↗