Cellulitis caused by Roseomonas mucosa in a child: a case report.

BACKGROUND: Roseomonas mucosa (R. mucosa) is a pink-pigmented, Gram-negative short rod bacterium. It is isolated from moist environments and skin, resistant to multiple drugs, including broad-spectrum cephalosporins, and a rare cause of infection with limited reports. R. mucosa mostly causes catheter-related bloodstream infections, with even fewer reports of skin and soft tissue infections. CASE PRESENTATION: A 10-year-old boy received topical steroid treatment for sebum-deficient eczema. A few days before the visit, he was bitten by an insect on the front of his right lower leg and scratched it due to itching. The day before the visit, redness, swelling, and mild pain in the same area were observed. Based on his symptoms, he was diagnosed with cellulitis. He was treated with sulfamethoxazole/trimethoprim, and his symptoms improved. Pus culture revealed R. mucosa. CONCLUSIONS: We report a rare case of cellulitis caused by R. mucosa. Infections caused by rare organisms that cause opportunistic infections, such as R. mucosa, should be considered in patients with compromised skin barrier function and regular topical steroid use. Gram stain detection of organisms other than Gram-positive cocci should be considered.

Roseomonas populi sp. nov., an acetate-degrading bacteria isolated from the stem of Populus tomentosa.

Strain CN29T, isolated from the stem of 5- to 6-year-old Populus tomentosa in Shandong, China, was characterized using a polyphasic taxonomic approach. Cells of CN29T were Gram-stain negative, aerobic, nonspore-forming, and nonmotile coccoid. Growth occurred at 20-37 °C, pH 4.0-9.0 (optimum, pH 6.0), and with 0-1% NaCl (optimum, 1%). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain CN29T was closely related to members of the genus Roseomonas and closest to Roseomonas pecuniae N75T (96.6%). This classification was further supported by phylogenetic analysis using additional core genes. The average nucleotide identity and digital DNA‒DNA hybridization values between strain CN29T and Roseomonas populi CN29T were 82.7% and 27.8%, respectively. The genome size of strain CN29T was 5.87 Mb, with a G + C content of 70.9%. The major cellular fatty acids included summed feature 8 (C18:1 ω7c/C18:1 ω6c), C19:0 cyclo ω8c and C16:0. The major respiratory quinone was Q-10. The polar lipids were phosphatidylcholine, aminolipid, phosphatidylglycerol, and diphosphatidylglycerol. Strain CN29T can utilize acetate as a carbon source for growth and metabolism. Additionally, it contains acid phosphatase (2-naphthyl phosphate), which catalyzes the hydrolysis of phosphoric monoesters. The CN29T strain contains several genes, including maeB, gdhB, and cysJ, involved in carbon, nitrogen, and sulfur cycling. These findings suggest that the strain may actively participate in ecosystem cycling, leading to soil improvement and promoting the growth of poplar trees. Based on the phylogenetic, phenotypic, and genotypic characteristics, strain CN29T is concluded to represent a novel species of the genus Roseomonas, for which the name Roseomonas populi sp. nov. is proposed. The type strain is CN29T (= JCM 35579T = GDMCC 1.3267T).

Roseomonas fluvialis sp. nov., an aerobic bacteriochlorophyll a-containing freshwater bacterium isolated from river epilithic biofilm.

A strictly aerobic bacteriochlorophyll a-containing alphaproteobacterium, designated strain S08T, was isolated from a biofilm sampled at Tama River in Japan. The non-motile and rod-shaped cells formed pink-beige pigmented colonies on agar plates containing organic compounds and showed in vivo absorption maxima at 798 and 866 nm in the near-infrared region, typical for the presence of bacteriochlorophyll a. The new bacterial isolate is Gram-negative, oxidase-negative and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain S08T was closely related to species in the genus Roseomonas. The closest phylogenetic relative of strain S08T was Roseomonas lacus TH-G33T (98.2 % sequence similarity). The major cellular fatty acids were C16 : 0, C18 : 1 2-OH and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). The predominant respiratory quinone was ubiquinone-9. The major polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an aminolipid. The G+C content of the genomic DNA was 70.6 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain S08T and the related Roseomonas type strains were all far lower than the cut-off value for the delineation of species. The results of polyphasic comparisons showed that strain S08T was clearly distinguishable from other members of the genus Roseomonas. Therefore, we propose a new species in the genus Roseomonas, namely, Roseomonas fluvialis sp. nov. The type strain is S08T (=DSM 111902T=NBRC 112025T).

Roseomonas acroporae sp. nov., isolated from coral Acropora digitifera.

A non-motile, rod-shaped, pink-pigmented bacterium NAR14T was isolated from coral Acropora digitifera from Daya Bay, Shenzhen, PR China. Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. NAR14T grew with 0-6 % (w/v) NaCl (optimum, 2-4 %), at 10-41 °C (optimum, 28 °C) and at pH 4.0-9.5 (optimum, 5.0). The major respiratory quinone was Q-10. The predominant fatty acids (more than 10%) were summed feature 8 (65.6 %) and C16 : 0 (17.6%). The DNA G+C content of NAR14T was 73.6 %. The polar lipids of NAR14T comprised one diphosphatidylglycerol, one phosphatidylethanolamine, one phosphatidylglycerol, one phosphatidylcholine, one aminolipid and three unknown polar lipids. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that NAR14T formed a lineage within the genus Roseomonas of the family Acetobacteraceae, and it was distinct from the most closely related species Roseomonas wooponensis JCM 19527T and Roseomonas riguiloci JCM 17520T with the 16S rRNA gene sequence similarities of 94.61 and 93.98 %, respectively. Phenotypic characteristics (physiological, biochemical and chemotaxonomic) also supported the taxonomic novelty of this isolate. Thus, NAR14T is considered to represent a novel species within the genus Roseomonas, for which the name Roseomonas acroporae sp. nov. is proposed. The type strain is NAR14T (=KCTC 92174T = MCCC 1K07275T).

Methylorubrum rhodesianum M520 as a biocontrol agent against Meloidogyne incognita (Tylenchida: Heteroderidae) J2s infecting cucumber roots.

AIMS: Root-knot nematodes (RKNs) are plant pathogens that cause huge economic losses worldwide. The biological management of RKNs may be a sustainable alternative to chemical control methods. Here, the biocontrol potential of Methylorubrum rhodesianum M520 against the RKN Meloidogyne incognita was investigated to theoretically support its application as a biocontrol agent in field production. METHODS AND RESULTS: In-vitro assays showed 91.9% mortality of M. incognita second-stage juveniles in the presence of strain M520 and that the hatching rate of M. incognita eggs was 21.7% lower than that of eggs treated with sterile water. In pot experiments, the M520 treatment caused 70.8% reduction in root-knots and increased plant shoot length and stem and root fresh weights, compared to control plant values. In split-root experiments, cucumber roots treated with M520 showed 25.6% decrease in root gall number, compared to that in control roots. CONCLUSION: M520 has multiple mechanisms against RKNs and might be used as a biocontrol agent against M. incognita in cucumber, laying a foundation for further studying M520 biocontrol against RKNs.

Microvirga terrestris sp. nov., and Microvirga arvi sp. nov., isolated from soil in South Korea.

Two novel Gram-stain-negative, aerobic, rod shaped bacterial strains BT290T and BT689T were isolated from soil collected in South Korea. Colony morphologies of both strains were circular and convex while the colors of BT290T and BT689T were light-pink and white, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that BT290T and BT689T belong to a distinct lineage within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alphaproteobacteria, phylum Proteobacteria, kingdom Bacteria). The 16S rR NA gene sequence similarity between two strains was 97.9%. Both strains had the similar quinone system, with ubiquinone 10 (Q-10) as the major respiratory quinone. The major polar lipids of strains BT290T and BT689T were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylcholine (PC), and phosphatidylglycerol (PG). The major cellular fatty acids of strain BT290T were C18:1 ω7c (58.2%) and C16:0 (17.7%), while those of strain BT689T were C18:1 ω7c (61.8%) and C16:0 (10.8%). On the bases of polyphasic analysis (phylogenetic, chemotaxonomic, and biochemical), strains BT290T and BT689T can be suggested as novel bacterial species within the genus Microvirga and the proposed names are Microvirga terrestris and Microvirga arvi, respectively. The type strain of Microvirga terrestris is BT290T (= KCTC 72367T = NBRC 114844T) and the type strain of Microvirga arvi is BT689T (= KACC 22016T = NBRC 114858T), respectively.

Roseomonas rosulenta sp. nov., isolated from rice paddy soil.

Three bacterial isolates, Gram-stain-negative, non-motile, coccobacilli-shaped bacteria, strains OP-27T, OP-5 and OP-30, were isolated from rice paddy soil. Phylogenetic analyses based on 16S rRNA gene sequences revealed that three isolates belonged to the genus Roseomonas, showing the highest sequence similarities to Roseomonas sediminicola FW-3T (98.1%) and Roseomonas lacus TH-G33T (98.0%). The genome size of strain OP-27T was 5.2 Mb in a single contig with DNA G+C content of 71.2%. The genome included 5164 predicted protein-coding genes, as well as 48 tRNA, 4 rRNA and 4 mRNA genes. The average nucleotide identity value between strain OP-27T and type strains of related species of the genus Roseomonas were 81.1-83.1%, and the digital DNA-DNA hybridization values of strain OP-27T and the related strains were 24.6-26.8%, respectively. The DNA-DNA hybridization values between strains OP-27T, OP-5 and OP-30 were 84-100% and its closest relative, Roseomonas sediminicola KACC 16616T was 21.1%. The major fatty acids were C18:1 ω7c, C18:1 2-OH and C16:0 and predominant quinone was Q-10. Based on its distinctive phenotypic, phylogenetic, and chemotaxonomic characteristics, the three strains are considered to represent novel species of the genus Roseomonas, for which the name Roseomonas rosulenta sp. nov. is proposed. The type strain is OP-27T (=KACC 21501T= NBRC 114497T).

Microvirga puerhi sp. nov., isolated from Puerh tea garden soil.

Strain WGZ8T was isolated from a soil sample of Puerh tea garden in Pu'er city, Southwest China. The isolate was rod-shaped, Gram-stain negative, facultative anaerobic, non-motile. Growth occurred within 0-3.0% (w/v) NaCl (optimal concentration, 0-1.0%), pH 5.0-11.0 (optimal pH, 7.0) and 10-40 °C (optimal temperature, 28 °C). 16S rRNA gene sequence-based phylogenetic and phylogenomic analysis revealed that WGZ8T belonged to the genus Microvirga. Its major cellular fatty acids were C19:0 cyclo ω8c, C16:0, C18:1ω7c and/or C18:1ω6c. The profile of polar lipids included phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol and phosphatidylglycerol. The only respiratory quinone was detected as ubiquinone 10 (Q-10). The genome size of strain WGZ8T was 5.17 MB, and the content of DNA G + C was 61 mol%. Based on the results of digital DNA-DNA hybridization and phenotypic results, strain WGZ8T could be concluded as a novel species of the genus Microvirga, for which the name Microvirga puerhi sp. nov. is proposed. The type strain is WGZ8T (= CGMCC 1.19171 T = JCM 35317 T).

Microvirga splendida sp. nov., bacteria isolated from soil.

Two bacterial strains, BT325T and BT690, were isolated from soil samples collected in Korea. Both strains were Gram stain-negative, short rod-shaped, and formed light-pink colored colonies. The 16S rRNA sequence similarity of strains BT325T and BT690 shared a sequence similarity of 99.7%. Both strains shared the highest 16S rRNA gene similarity of 98.6% with Microvirga arabica SV2184PT, followed by Microvirga ossetica V5/3 M T (98.5% and 98.2%, respectively), Microvirga soli R491T (98.3% and 98.2%, respectively), Microvirga aerilata (98.2% and 98.08%, respectively), Microvirga makkahensis (98.08% and 97.8%, respectively). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain BT325T and BT690 were positioned in a distinct lineage within the family Methylobacteriaceae (order Rhizobiales, class Alphaproteobacteria). The genome size of strain BT325T was 5,200,315 bp and the genomic DNA G + C content was 64.3 mol%. The sole respiratory quinone of strain BT325T was Q-10 and the predominant cellular fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c) and summed feature 8 (C18:1 ω7c/C18:1 ω6c). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. Polyphasic taxonomic analysis of biochemical, chemotaxonomic, and phylogenetic analyses suggested that strains BT325T represents a novel bacterial species within the genus Microvirga, for which the name Microvirga splendida is proposed. The type strain of Microvirga splendida is BT325T (= KCTC 72406 T = NBRC 114847 T).

Cardiac tamponade due to perforation of a Roseomonas mucosa pyogenic hepatic abscess as initial presentation of hepatoid carcinoma.

Hepatic abscesses can rarely cause pericardial disease by erosion into the pericardial space and present with haemodynamic instability due cardiac tamponade. While rare, these dramatic presentations are more often due to amoebic abscesses than bacterial abscesses. Importantly, a cause must be found for any cryptogenic hepatic abscess regardless of presentation, as there is a high association with underlying malignancy. We report a previously healthy man in his 30s who presented with cardiac tamponade from perforation of a Roseomonas mucosa pyogenic hepatic abscess into the pericardium in the absence of bacteremia and biliary disease. One year later, he was found to have diffusely metastatic hepatoid carcinoma.

Microvirga jeongseonensis sp. nov., isolated from soil in South Korea.

A novel Gram-stain-negative, aerobic, rod-shaped, convex, and light pink-colored strain BT688T was isolated from a soil sample collected in Jeongseon City, South Korea. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain BT688T belongs to a distinct lineage within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alphaproteobacteria, phylum Proteobacteria). The 16S rRNA gene sequence similarity between strain BT688T and Microvirga aerilata 5420S-16T was 98.5%. Strain BT688T had Q-10 as a major respiratory quinone and the major polar lipids were diphosphatidilglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC). The major cellular fatty acids of strain BT688T were C18:1 ω7c (76.0%) and summed feature 3 (9.6%). Based on the polyphasic characteristics, strain BT688T represents a novel bacterial species within the genus Microvirga and the proposed name is Microvirga jeongseonensis. The type strain of Microvirga jeongseonensis is BT688T (= KCTC 82701T = NBRC 114857T).

Roseomonas rubea sp. nov., isolated from rice paddy soil.

Three pale-red-pigmented, Gram-stain-negative, coccobacilli-shaped, motile and strictly aerobic bacteria, strains MO17T, MO41 and NPKOSM1, were isolated from rice paddy soil. Colonies were circular with entire edges, convex and pale red. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains MO17T, MO41 and NPKOSM1 belonged to the genus Roseomonas and were closely related to Roseomonas sediminicola FW-3T (98.2 %), Roseomonas oryzicola YC6724T (98.0 %), Roseomonas soli 5N26T (98.0 %), Roseomonas eburnea BUT-5T (97.8 %), Roseomonas alkaliterrae YIM 78007T (97.7 %), Roseomonas lacus TH-G33T (97.6 %) and Roseomonas terrae DS-48T (96.8 %). The DNA-DNA hybridization values between strains MO17T, MO41 and NPKOSM1 were 84-92 %, and the values between the three strains and their close phylogenetic relatives were also below 70 %. The major cellular fatty acids were C18 : 1 ω7c, C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2OH). The predominant respiratory quinone was identified as Q-10. The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one unidentified aminophospholipid and two unknown phospholipids. Based on their distinctive phenotypic, phylogenetic and chemotaxonomic characteristics, the three strains are considered to represent novel species of the genus Roseomonas for which the name Roseomonas rubea sp. nov. is proposed. The type strain is MO17T (=KACC 19933T=NBRC 114495T).

Characterization of a halotolerant GH2 family ß-galactosidase GalM from Microvirga sp. strain MC18.

A new glycoside hydrolase family 2 (GH2) ß-galactosidase encoding gene galM was cloned from Microvirga sp. strain MC18 and overexpressed in Escherichia coli. The recombinant ß-galactosidase GalM showed optimal activity at pH 7.0 and 50 °C, with a stability at pH 6.0-9.0 and 20-40 °C, which are conditions suitable for the diary environment. The Km and Vmax values for o-nitrophenyl-ß-d-galactopyranoside (oNPG) were 1.30 mmol/L and 15.974 µmol/(min·mg), respectively. GalM showed low product inhibition by galactose with a Ki of 73.18 mM and high tolerance for glucose that 86.5% activity retained in the presence of 500 mM glucose. It was also stable and active in 20% of methanol, ethanol and isopropanol. In addition, the enzyme activity of GalM was activated significantly over 0-2 mol/L NaCl (1.6-4.3 fold). These favorable properties make GalM a potential candidate for the industrial application.

Isolation and characterization of tick-borne Roseomonas haemaphysalidis sp. nov. and rodent-borne Roseomonas marmotae sp. nov.

Four novel Gram-negative, mesophilic, aerobic, motile, and cocci-shaped strains were isolated from tick samples (strains 546T and 573) and respiratory tracts of marmots (strains 1318T and 1311). The 16S rRNA gene sequencing revealed that strains 546T and 573 were 97.8% identical to Roseomonas wenyumeiae Z23T, whereas strains 1311 and 1318T were 98.3% identical to Roseomonas ludipueritiae DSM 14915T. In addition, a 98.0% identity was observed between strains 546T and 1318T. Phylogenetic and phylogenomic analyses revealed that strains 546T and 573 clustered with R. wenyumeiae Z23T, whereas strains 1311 and 1318T grouped with R. ludipueritiae DSM 14915T. The average nucleotide identity between our isolates and members of the genus Roseomonas was below 95%. The genomic G+C content of strains 546T and 1318T was 70.9% and 69.3%, respectively. Diphosphatidylglycerol (DPG) and phosphatidylethanolamine (PE) were the major polar lipids, with Q-10 as the predominant respiratory quinone. According to all genotypic, phenotypic, phylogenetic, and phylogenomic analyses, the four strains represent two novel species of the genus Roseomonas, for which the names Roseomonas haemaphysalidis sp. nov. and Roseomonas marmotae sp. nov. are proposed, with 546T (= GDMCC 1.1780T = JCM 34187T) and 1318T (= GDMCC 1.1781T = JCM 34188T) as type strains, respectively.

Characterization of lipopeptide biosurfactant produced by a carbazole-degrading bacterium Roseomonas cervicalis: The role of biosurfactant in carbazole solubilisation.

AIM: Characterization of biosurfactant produced by a carbazole-degrading bacterium Roseomonas cervicalis and proteomic analysis of intracellular proteins of bacterium while growing on glucose and carbazole medium. METHODS AND RESULTS: The bacterium R. cervicalis was isolated from a soil sample contaminated with crude petroleum oil. PCR amplification ascertained the existence of some hydrocarbon-degrading catabolic genes (alkB and PAH-RHDα, C12O, and C23O) in the bacterial genome. GC-MS and RP-HPLC analyses demonstrated 62% and 60% carbazole degradation, respectively, by R. cervicalis 144 h post-incubation at 37℃ and pH 6.5. Due to the paucity of protein databases, expressions of only 29 and 14 intracellular proteins were explicitly recognized and quantitated by mass spectrometry analysis when R. cervicalis was grown in carbazole and glucose medium, respectively. FTIR, NMR and HR-MS/MS analyses demonstrated the lipopeptide nature of the purified biosurfactant produced by R. cervicalis. The biosurfactant is also presumed to assist in the solubilization of carbazole. CONCLUSION: The isolated R. cervicalis strain is a potential candidate for the bioremediation of carbazole in petroleum-oil-contaminated sites. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of the promising R. cervicalis strain proficient in carbazole biodegradation.

Roseomonas ponticola sp. nov., a novel bacterium isolated from Pearl River estuary.

A novel species of the genus Roseomonas, designated SYSU M41301T, was isolated from water sample of the Pearl River estuary in Guangdong, China. Polyphasic, taxonomic and phylogenomic analyses were used to determine the taxonomy position of the strain. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain SYSU M41301T showed the highest sequence similarity to Roseomonas stagni KCTC 22213T (97.9 %) and Roseomonas riguiloci KCTC 23339T (96.4 %). The novel species could be differentiated from other species of the genus Roseomonas by its distinct phenotypic and genotypic characteristics. The isolate was Gram-staining-negative, aerobic, short rod-shape, oxidase-positive and non-motile. The predominant respiratory quinone was ubiquinone 8 (Q-8). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and one unidentified polar lipid. The major fatty acids (>10 % of total) were 11-methyl C18 : 1 ω7c, summed feature 3 (C16 : 1 ω7c and/ or C16 : 1 ω6c) and summed feature 8 (C18:  :1 ω7c and/or C18 : 1 ω6c). The G+C content of the novel isolate based on genomic DNA was 72.0 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU M41301T should be considered to represent a novel species in the genus Roseomonas, for which the name Roseomonas ponticola sp. nov. is proposed with the type strain SYSU M41301T (=KCTC 72726T=CGMCC 1.18613T).

Description and genome analysis of Microvirga antarctica sp. nov., a novel pink-pigmented psychrotolerant bacterium isolated from Antarctic soil.

A novel pink-pigmented bacterium, designated strain 3D7T, was isolated during an investigation of potential psychrotolerant species from Antarctic soil. Cells of the isolate were observed to be rod-shaped (0.7-0.9 × 1.0-2.2 µm), Gram-stain negative and non-motile. It was able to grow at 4-32  °C, pH 7.0-10.0 and in the presence of 0-3% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 3D7T belongs to the genus Microvirga and was most closely related to 'Microvirga brassicacearum' CDVBN77T (98.3%), Microvirga subterranea DSM 14364 T (96.8%), Microvirga guangxiensis 25BT (96.5%) and Microvirga aerophila DSM 21344 T (96.5%). The predominant quinone was ubiquinone 10 (Q-10), and the major fatty acids were summed feature 8 (C18:1ω7c and/or C18:1ω6c) and C19:0 cyclo ω8c. The predominant polar lipids were phosphatidylcholine and phosphatidylethanolamine. The genomic DNA G + C content of strain 3D7T was 63.5 mol%. Its genome sequence showed genes encoding phosphatases and lipases. Genetic machinery related to carbohydrate-active enzymes and secondary metabolites were also observed. The average nucleotide identity and digital DNA-DNA hybridization values based on whole genome sequences of strain 3D7T and its closely related species were below the threshold range for species determination. Phenotypic, chemotaxonomic, phylogenetic and genomic analyses suggested that strain 3D7T represents a novel species of the genus Microvirga, for which the name Microvirga antarctica sp. nov. is proposed. The type strain is 3D7T (= CGMCC 1.13821T = KCTC 72465T).

Roseomonas oleicola sp. nov., isolated from an oil production mixture in Yumen Oilfield, and emended description of Roseomonas frigidaquae.

A pink, ovoid-shaped, Gram-stain-negative, strictly aerobic and motile bacterial strain, designated ROY-5-3T, was isolated from an oil production mixture from Yumen Oilfield in PR China. The strain grew at 4-42 °C (optimum, 30 °C), at pH 5-10 (optimum, 7) and with 0-5 % (w/v) NaCl (optimum, 0%). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that ROY-5-3T belongs to the genus Roseomonas and shared the highest pairwise similarities with Roseomonas frigidaquae CW67T (98.1%), Roseomonas selenitidurans BU-1T (97.8%), Roseomonas tokyonensis K-20T (97.7%) and Roseomonas stagni HS-69T (97.3%). The average nucleotide identity and digital DNA-DNA hybridization values between ROY-5-3T and other related type strains of Roseomonas species were less than 84.08 and 28.60 %, respectively, both below the species delineation threshold. Pan-genomic analysis showed that the novel isolate ROY-5-3T shared 3265 core gene families with the four closely related type strains in Roseomonas, and the number of strain-specific gene families was 513. The major fatty acids were identified as summed feature 8 (C18 : 1 ω6c/C18 : 1 ω7c), summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c) and C16 : 0. Strain ROY-5-3T contained Q-10 as the main ubiquinone and the genomic DNA G+C content was 69.8 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. Based on the phylogenetic, morphological, physiological, chemotaxonomic and genome analyses, strain ROY-5-3T represents a novel species of the genus Roseomonas for which the name Roseomonas oleicola sp. nov. is proposed. The type strain is ROY-5-3T (=CGMCC 1.13459T =KCTC 82484T).

[Response of Photosynthetic Bacterial Community to Cadmium Contamination in Paddy Soil].

Heavy metal pollution in rice fields leads to huge losses in rice yield every year and is thus of increasing concern. Therefore, it is important to understand the changes in the microecology and physicochemical properties of paddy soil under different levels of cadmium pollution. The purpose of this study was to investigate the response of the photosynthetic bacterial community in paddy soil to different cadmium pollution levels using 16S sequencing technology. The results showed that pH, total cadmium, and available cadmium content decreased gradually with the increase in cadmium pollution. The soil α diversity was slightly different in the high cadmium (Cd), medium Cd, and low Cd groups; however, the enriched photosynthetic populations and photosynthetic bacterial communities were significantly different among these groups. The effective connections between photosynthetic bacterial species in the high Cd group were significantly greater than those in the medium and low Cd groups, the connections were closer, and the density was higher. Alkaline nitrogen, pH, available (P/K), total (N/P), organic matter, total cadmium, and available cadmium were important factors affecting the photosynthetic bacterial community and were significantly correlated with the photosynthetic bacterial community, explaining 59.90% of the variation in the photosynthetic bacterial community. Effective Cd content was significantly positively correlated with Methylorubrum populi, Methylorubrum extorquens, Methylobacterium sp. Leaf125, and Rhodopseudomonas sp. AAP120 (R>0.05, P<0.05). This study will provide a theoretical basis for the microbial remediation of cadmium contamination in paddy fields. This study is important for understanding the effects of cadmium pollution on specific functional microbial populations in paddy soils.

Microvirga pudoricolor sp. nov., and Microvirga alba sp. nov., isolated from soil in South Korea.

Two novel Gram-stain-negative, aerobic, rod-shaped, circular, convex, light-pink and white-colored bacterial strains BT291T and BT350T were isolated from soil collected in Uijeongbu city (37° 44' 55″ N, 127° 2' 20″ E) and Jeju island (33° 22' 48″ N, 126° 31' 48″ E), respectively, South Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that each of the strains BT291T and BT350T belong to a distinct lineages within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alpha Proteobacteria, phylum Proteobacteria, kingdom Bacteria). The 16S rRNA gene sequence similarity between the two strains BT291T and BT350T was 97.4%. The two strains were found to have the same quinone system, with Q-10 as the major respiratory quinone. The major polar lipids of strains BT291T and BT350T were phosphatidylethanolamine (PE), diphosphatydilglycerol (DPG), phosphatidylcholine (PC) and phosphatidylglycerol (PG). The major cellular fatty acids of strain BT291T were C18:1 ω7c (58.2%) and cyclo-C19:0 ω8c (25.7%). The major cellular fatty acids of strain BT350T were C18:1 ω7c (38.5%) and cyclo-C19:0 ω8c (27.7%). Based on the polyphasic analysis (phylogenetic, chemotaxonomic and biochemical), strains BT291T and BT350T can be suggested as two novel bacterial species within the genus Microvirga and the proposed names are Microvirga pudoricolor and Microvirga alba, respectively. The type strain of Microvirga pudoricolor is BT291T (= KCTC 72368T = NBRC 114845T) and the type strain of Microvirga alba is BT350T (= KCTC 72385T = NBRC 114848T).