Draft genome sequence of Sphingomonas echinoides ATCC 14820

Impacts of partially hydrolyzed polyacrylamide (HPAM) on microbial mats from a constructed wetland treating oilfield produced water

Constructed wetlands have been successfully used in the treatment of produced water brought to the surface in large quantities during oil extraction activities. However, with the increasing use of partially hydrolyzed polyacrylamide (HPAM) in enhancing oil recovery, the impacts of HPAM on the biological processes of wetlands is still unknown. Microbial mats in wetlands play a key role in hydrocarbon degradation. Here, we compared the bacterial communities of four wetland microbial mats after flooding with different concentrations of HPAM. Two mats (i.e. the HPAM-free and the 500 ppm HPAM pre-exposed mats) were selected to further investigate the effect of HPAM on respiration and biodegradation activities. The field mats exhibited clear differences in their bacterial community structure, where Cyanobacteria and Alphaproteobacteria became dominant in the presence of HPAM. In the laboratory experiments, the generated CO₂ by the HPAM-free and the 500 ppm HPAM pre-exposed mats did not vary significantly when HPAM was added, although CO₂ values were slightly higher in the presence of oil. Both mats were still able to degrade between 15 ± 14.4 to 50 ± 13.0% of C₁₀ to C₃₀ alkanes in 28 days, and this degradation was not affected by HPAM addition. The HPAM concentration decreased by 22-34% of the initial amount after 28 days of incubation in the HPAM-free mat, versus only 7-18.4% decrease in the 500 ppm HPAM pre-exposed mat. We conclude that the wetland microbial mats seem to have become well adapted to HPAM and could maintain their respiration and hydrocarbon degradation activities.

Sphingomonas changnyeongensis sp. nov. isolated from the Hapcheon–Changnyeong barrage area in the Nakdong river

The novel bacterial strain C33T was isolated from a freshwater sample collected from the Hapcheon–Changnyeong barrage. The Gram-negative, motile, yellow-pigmented strain C33T was characterized as a rod-shaped and strictly aerobic bacterium. A 16S-rRNA phylogenetic analysis revealed that this strain was most closely related to Sphingomonas changbaiensis V2M44T, Sphingomonas tabacisoli X1-8T, and Sphingomonas flavalba ZLT-5T with 97.1, 97.0, and 95.0 % 16S-rRNA sequence similarities, respectively. The genomic DNA GC content of strain C33T was estimated at 65.0 mol%. The average nucleotide identity of strain C33T relative to S. changbaiensis V2M44T and S. flavalba ZLT-5T was found to be 77.0 and 75.6%, with average amino-acid identities of 69.9, and 66.7%, and the digital DNA–DNA hybridization values of 21.3 and 17.7 %, respectively. The cells grew at 19–37 °C and pH 6–9 with 0–0.5 % (w/v) NaCl (optimum: 28 °C, pH 6.5, and 0 % NaCl). The major component identified in the polyamine pattern was sym-homospermidine, and the main ubiquinone was Q-10. The predominant polar lipids characterized were diphophatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, and sphingoglycolipid. Iso-C15 : 0, C15 : 0 anteiso, and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) were found to be the primary cellular fatty acids in strain C33T. Based on these genotypic and phenotypic characteristics, strain C33T was classified as a novel species of the genus Sphingomonas ; and the name Sphingomonas changnyeongensis sp. nov. is proposed (=KACC 21511T=JCM 33880T).

Comprehensive Genome Analysis on the Novel Species Sphingomonas panacis DCY99T Reveals Insights into Iron Tolerance of Ginseng

Plant growth-promoting rhizobacteria play vital roles not only in plant growth, but also in reducing biotic/abiotic stress. Sphingomonas panacis DCY99T is isolated from soil and root of Panax ginseng with rusty root disease, characterized by raised reddish-brown root and this is seriously affects ginseng cultivation. To investigate the relationship between 159 sequenced Sphingomonas strains, pan-genome analysis was carried out, which suggested genomic diversity of the Sphingomonas genus. Comparative analysis of S. panacis DCY99T with Sphingomonas sp. LK11 revealed plant growth-promoting potential of S. panacis DCY99T through indole acetic acid production, phosphate solubilizing, and antifungal abilities. Detailed genomic analysis has shown that S. panacis DCY99T contain various heavy metals resistance genes in its genome and the plasmid. Functional analysis with Sphingomonas paucimobilis EPA505 predicted that S. panacis DCY99T possess genes for degradation of polyaromatic hydrocarbon and phenolic compounds in rusty-ginseng root. Interestingly, when primed ginseng with S. panacis DCY99T during high concentration of iron exposure, iron stress of ginseng was suppressed. In order to detect S. panacis DCY99T in soil, biomarker was designed using spt gene. This study brings new insights into the role of S. panacis DCY99T as a microbial inoculant to protect ginseng plants against rusty root disease.

Draft genomic DNA sequence of the multi-resistant Sphingomonas sp. strain AntH11 isolated from an Antarctic hypolith

Hypoliths are microbial communities that live underneath translucent rocks in desert ecosystems and represent a key refuge niche in the Antarctic Dry Valleys. These cryptic microbial assemblages are crucial as they mediate numerous ecosystem processes. Here, we present the first draft genome of a hypolith isolate belonging to the α-proteobacterial class and the genus Sphingomonas. The draft genome of Sphingomonas sp. strain AntH11 shows the capacity of this organism to adapt to the extreme cold and arid conditions encountered in Antarctic desert soils. Our result also suggests that its metabolic versatility and multidrug resistance constitutes an opportunistic advantage in competition with other hypolith-colonizing microorganisms.

Comparison of 26 sphingomonad genomes reveals diverse environmental adaptations and biodegradative capabilities

Sphingomonads comprise a physiologically versatile group within the Alphaproteobacteria that includes strains of interest for biotechnology, human health, and environmental nutrient cycling. In this study, we compared 26 sphingomonad genome sequences to gain insight into their ecology, metabolic versatility, and environmental adaptations. Our multilocus phylogenetic and average amino acid identity (AAI) analyses confirm that Sphingomonas, Sphingobium, Sphingopyxis, and Novosphingobium are well-resolved monophyletic groups with the exception of Sphingomonas sp. strain SKA58, which we propose belongs to the genus Sphingobium. Our pan-genomic analysis of sphingomonads reveals numerous species-specific open reading frames (ORFs) but few signatures of genus-specific cores. The organization and coding potential of the sphingomonad genomes appear to be highly variable, and plasmid-mediated gene transfer and chromosome-plasmid recombination, together with prophage- and transposon-mediated rearrangements, appear to play prominent roles in the genome evolution of this group. We find that many of the sphingomonad genomes encode numerous oxygenases and glycoside hydrolases, which are likely responsible for their ability to degrade various recalcitrant aromatic compounds and polysaccharides, respectively. Many of these enzymes are encoded on megaplasmids, suggesting that they may be readily transferred between species. We also identified enzymes putatively used for the catabolism of sulfonate and nitroaromatic compounds in many of the genomes, suggesting that plant-based compounds or chemical contaminants may be sources of nitrogen and sulfur. Many of these sphingomonads appear to be adapted to oligotrophic environments, but several contain genomic features indicative of host associations. Our work provides a basis for understanding the ecological strategies employed by sphingomonads and their role in environmental nutrient cycling.

Genome sequences published outside of Standards in Genomic Sciences, March-April 2012

The purpose of this table is to provide the community with a citable record of publications of ongoing genome sequencing projects that have led to a publication in the scientific literature. While our goal is to make the list complete, there is no guarantee that we may have omitted one or more publications appearing in this time frame. Readers and authors who wish to have publications added to subsequent versions of this list are invited to provide the bibliographic data for such references to the SIGS editorial office.