RESUMO
Bacterial strain H4R21T was isolated from beech rhizosphere soil sampled in the forest experimental site of Montiers (Meuse, France). It effectively weathers minerals, hydrolyses chitin and produces quorum sensing signal molecules. The strain is aerobic and Gram-stain-negative. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain H4R21T belongs to the genus Collimonas with high sequence similarity to C. arenae Ter10T (99.38â%), C. fungivorans Ter6T(98.97â%), C. pratensis Ter91T (98.76â%), C. humicola RLT1W51T (98.46â%) and C. silvisoli RXD178 T (98.46â%), but less than 98â% similarity to other strains of the genus Collimonas. The predominant quinone in H4R21T is ubiquinone-8 (Q8). The major polar lipids are diphosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and lipid. The major fatty acids identified were C12â:â0, C12:0 3-OH, C16ââ:ââ0 and C17:0âcyclo. The digital DNA G+C content of the genomic DNA was 59.5âmol%. Furthermore, the strain could be clearly distinguished from its closely related type strains by a combination of phylogenomic and in silico DNA-DNA hybridization results, and phenotypic characteristics. Therefore, strain H4R21T represents a novel species within the genus Collimonas, for which the name Collimonas rhizosphaerae sp. nov. is proposed, with strain H4R21T (=CFBP 9203T=DSM 117599T) as the type strain.
Assuntos
Fagus , Filogenia , Rizosfera , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Fagus/microbiologia , Ácidos Graxos , França , Hibridização de Ácido Nucleico , Fosfolipídeos/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , UbiquinonaRESUMO
A Gram-stain-negative, aerobic, non-motile and yellow-colored bacterium, strain 17J57-3 T, was isolated from soil collected in Pyeongchang city, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 17J57-3 T formed a distinct lineage within the family Oxalobacteraceae (order Burkholderiales, class Betaproteobacteria). Strain 17J57-3 T was the most closely related to Noviherbaspirillum humi U15T (96.4% 16S rRNA gene sequence similarity) and Noviherbaspirillum massiliense JC206T (96.2%). The draft genome size of strain 17J57-3 T was 6,117,206 bp. Optimal growth occurred at 30 °C, pH 7.0 without NaCl. The predominant cellular fatty acids were summed feature 3 (C16:1 ω6c/C16:1 ω7c) and C16:0. The major respiratory quinone was Q-8. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strain 17J57-3 T represents a novel bacterial species within the genus Noviherbaspirillum, for which the name Noviherbaspirillum galbum is proposed. The type strain of Noviherbaspirillum galbum is 17J57-3 T (= KCTC 62213 T = NBRC 114384 T).
Assuntos
Oxalobacteraceae/classificação , Filogenia , Microbiologia do Solo , Ácidos Graxos , Oxalobacteraceae/genética , Fosfolipídeos , RNA Ribossômico 16S/genética , República da Coreia , Especificidade da EspécieRESUMO
An orange-coloured, rod-shaped, and aerobic bacterial strain DKR-6 T was isolated from oil-contaminated experimental soil. The strain was Gram-stain-negative, catalase and oxidase positive, and grew at temperature 10-42 °C, at pH 5.5-9.5, and at 0-3.0% (w/v) NaCl concentration. The phylogenetic analysis and 16S rRNA gene sequence analysis suggested that the strain DKR-6 T was affiliated to the genus Noviherbaspirillum, with the closest species being Noviherbaspirillum massiliense JC206T (96.3% sequence similarity). The chemotaxonomic profiles revealed the presence of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylcholine as the principal polar lipids; C16:0, C17:0 cyclo, summed feature 3 (C16:1ω7c and/or C16: 1ω6c), and summed feature 8 (C18:1ω7c/or C18:1ω6c) as the main fatty acids; and Q-8 as a sole ubiquinone. The DNA G + C content was 61.6%. The polyphasic taxonomic features illustrated in this study clearly implied that strain DKR-6 T represents a novel species in the genus Noviherbaspirillum, for which the name Noviherbaspirillum pedocola sp. nov. is proposed with the type strain DKR-6 T (= KACC 22074 T = NBRC 114727 T).
Assuntos
Oxalobacteraceae , Fosfolipídeos , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Oxalobacteraceae/classificação , Oxalobacteraceae/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo/química , Especificidade da EspécieRESUMO
We isolated two new soil bacteria: ONC3T (from garden soil in NC, USA; LMG 31738T=NRRL B-65553T) and M1T (from farmed soil in MI, USA; NRRL B-65551T=ATCC TSD-197T=LMG 31739T) and characterized their metabolic phenotype based on Biolog, MALDI-TOF MS and fatty acid analyses, and compared 16S rRNA and whole genome sequences to other members of the Oxalobacteraceae after sequencing on an Illumina Nextera platform. Based on the results of 16S rRNA sequence analysis, ONC3T shows the highest sequence similarity to Massilia solisilvae J18T (97.8â%), Massilia terrae J11T (97.7â%) and Massilia agilis J9T (97.3â%). Strain M1T is most closely related to Noviherbaspirillum denitrificans TSA40T, Noviherbaspirillum agri K-1-15T and Noviherbaspirillum autotrophicum TSA66T (sequence identity of 98.2, 98.0 and 97.8â%, respectively). The whole genome of ONC3T has an assembled size of 5.62 Mbp, a G+C content of 63.8âmol% and contains 5104 protein-coding sequences, 56 tRNA genes and two rRNA operons. The genome of M1T has a length of 4.71 MBp, a G+C content of 63.81âmol% and includes 4967 protein-coding genes, two rRNA operons and 44 tRNA genes. Whole genome comparisons identified Massilia sp. WG5 with a 79.3â% average nucleotide identity (ANI) and 22.6â% digital DNA-DNA hybridization (dDDH), and Massilia sp. UBA11196 with 78.2â% average amino acid identity (AAI) as the most closely related species to ONC3T. M1T is most closely related to N. autotrophicum TSA66T with an ANI of 80.27â%, or N. denitrificans TSA40T with a dDDH of 22.3â%. The application of community-accepted standards such as <98.7â% in 16S sequence similarity and <95-96â% ANI or 70â% DDH support the classification of Massilia horti ONC3T and Noviherbaspirillum arenae M1T as novel species within the Oxalobacteraceae.
Assuntos
Oxalobacteraceae/classificação , Oxalobacteraceae/isolamento & purificação , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Oxalobacteraceae/genética , Oxalobacteraceae/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo/químicaRESUMO
A Gram-negative, rod-shaped bacterium, strain Duganella callida DN04T, was isolated from the soil of a maize field in North Carolina, USA. Based on the 16S rRNA gene sequence, the most similar Duganella species are D. sacchari Sac-22T, D. ginsengisoli DCY83T, and D. radicis Sac-41T with a 97.8, 97.6, or 96.9â% sequence similarity, respectively. We compared the biochemical phenotype of DN04T to D. sacchari Sac-22T and D. zoogloeoides 115T and other reference strains from different genera within the Oxalobacteraceae and while the biochemical profile of DN04T is most similar to D. sacchari Sac-22T and other Duganella and Massilia strains, there are also distinct differences. DN04T can for example utilize turanose, N-acetyl-d-glucosamine, inosine, and l-pyroglutamic acid. The four fatty acids found in the highest percentages were C15â:â0 iso (24.6â%), C15â:â1 isoG (19.4â%), C17â:â0 iso3-OH (16.8â%), and summed feature 3 (C16:1 âµ7c and/or C16:1 âµ6c) (12.5â%). We also applied whole genome sequencing to determine if DN04T is a novel species. The most similar AAI (average amino acid identity) score was 70.8â% (Massilia plicata NZ CP038026T), and the most similar ANI (average nucleotide identity) score was 84.8â% (D. radicis KCTC 22382T), which indicates that DN04T is a novel species. The genome-to-genome-distance calculation (GGDC) revealed a DDH of 28.3â% to D. radicis KCTC 22382T, which is much lower than the new species threshold. Based on the morphological, phenotypic, and genomic differences, we propose Duganella callida sp. nov. as a novel species within the Duganella genus (type strain DN04T=NRRL B-65552T=LMG 31736T).
Assuntos
Oxalobacteraceae/classificação , Filogenia , Microbiologia do Solo , Zea mays , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , North Carolina , Hibridização de Ácido Nucleico , Oxalobacteraceae/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
A new aerobic betaproteobacterium, strain SA-152T, was isolated from the water of a crater lake. 16S rRNA gene sequence analysis revealed that strain SA-152T belonged to the family Oxalobacteraceae (order Burkholderiales) and was phylogenetically related to Solimicrobium silvestre S20-91T with 97.09â% and to Herminiimonas arsenicoxydans ULPAs1T with 96.00â% 16S rRNA gene pairwise sequence similarity. Cells of strain SA-152T were rod-shaped, non-motile, oxidase-negative and catalase-positive. Its fatty acid profile was dominated by two fatty acids, C16â:â1 ω7c and C16â:â0, the major respiratory quinones were Q-8 and Q-7, and the main polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The G+C content of the genomic DNA of strain SA-152T was 48.3 mol%. The new bacterium can be distinguished from closely related genera Solimicrobium, Herminiimonas, Rugamonas and Undibacterium based on its non-motile and oxidase-negative cells. On the basis of the phenotypic, chemotaxonomic and genomic data, strain SA-152T is considered to represent a novel species of a new genus, for which the name Sapientia aquatica gen. nov., sp. nov. is proposed. The type strain of Sapientia aquatica is SA-152T (=DSM 29805T=NCAIM B.02613T).
Assuntos
Lagos/microbiologia , Oxalobacteraceae/classificação , Filogenia , Microbiologia da Água , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oxalobacteraceae/isolamento & purificação , Fosfolipídeos/química , Quinonas/química , RNA Ribossômico 16S/genética , Romênia , Análise de Sequência de DNARESUMO
Strain MC02T, a Gram-stain-negative, rod-shaped bacterium, was isolated from field soil collected from California, USA. To examine if MC02T represents a novel species, we compared its colony morphology, 16S rRNA gene and whole genome sequence, and its metabolic phenotype using Biolog GenIII and MALDI-TOF analyses compared to reference strains. Based on 16S rRNA gene and whole genome sequencing, MC02T belongs to the genus Massilia and Massilia agri K-3-1T is the most similar strain with 96.97â% 16S rRNA gene sequence identity. MALDI-TOF analysis revealed that Massilia aerilata DSM19289T is the closest match, but the similarity score was much lower than the ≥1.7 threshold for a reliable identification at the genus level. The predominant fatty acids were summed feature 3 (C16â:â1âµ7c and/or C16â:â1âµ6c; 49.07â%) and C16â:â0 (30.01â%). The genome is 5.02 Mbp and the G+C content is 66.2âmol%. Whole genome comparisons to the closest related strains revealed an average amino acid identity value of 67.4â%, an OrthoANI similarity of 77.1â%, and a DNA-DNA-hybridization probability ≥70â%, confirming that MC02T represents a novel species. Strain MC02T can grow at pH 6 but not at pH 5, and a salt concentration of ≥1â% inhibits its growth. In contrast to other Massilia strains, MC02T can utilize turanose, inosine and l-serine. The genome of MC02T shows putative endophyte genes such as a nitrate reductase, several phosphatases, and biotin biosynthesis genes, 26 flagellar motility genes and 14 invasion and intracellular resistance genes. Based on its metabolic, physiological and genomic characteristics, we propose that strain MC02T (NRRL B-65554T=ATCC TSD-200T=LMG 31737T) represents a novel species of the genus Massilia with the name Massilia arenosa sp. nov.
Assuntos
Oxalobacteraceae/classificação , Filogenia , Microbiologia do Solo , Zea mays , Técnicas de Tipagem Bacteriana , Composição de Bases , California , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Oxalobacteraceae/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
A Gram-negative, psychrophilic bacterium, designated strain GS1T, was isolated from a forest soil sample collected from the West Peak of Mt. Yushan, Yushan National Park, Taiwan. Cells grown in broth cultures were mostly non-motile and non-flagellated, whereas motile cells with monotrichous, subpolar flagella were also observed. The novel strain grew over a temperature range of 4-25 °C with optimum growth at 10-15 °C. It grew aerobically and was not capable of anaerobic growth by fermentation of D-glucose or other carbohydrates. Ubiquinone 8 was the predominant isoprenoid quinone. The major polar lipids comprised phosphatidylethanolamine, diphosphatidylglycerol and dimethylaminoethanol. Cellular fatty acids were dominated by C16:1ω7c (35.2%), C16:0 (19.5%), C18:1ω7c (18.8%) and C17:0ω7c cyclo (15.5%). The DNA G + C content was 49.2 mol% evaluated according to the genomic sequencing data. Strain GS1T shared more than 96.5% 16S rRNA gene sequence similarities with type strains of four Collimonas species (97.2-97.5%), three Glaciimonas species (97.3% for each of the three) and Oxalicibacterium solurbis (96.5%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GS1T formed a stable genus-level clade with type strains of species in the genus Glaciimonas in the family Oxalobacteraceae and GS1T was an outgroup with respect to these Glaciimonas species. Characteristically, strain GS1T could be easily distinguished from the recognised Glaciimonas species by exhibition of swimming motility with monotrichous, subpolar flagellum in some of the cells, ability to grow in NaCl at 2% but not at 3% and the distinguishable fatty acid profiles. On the basis of the polyphasic taxonomic data from this study, strain GS1T is considered to represent a novel species of the genus Glaciimonas, for which the name Glaciimonas soli sp. nov. is proposed. The type strain is GS1T (= JCM 33275T = BCRC 81091T).
Assuntos
Florestas , Oxalobacteraceae/classificação , Oxalobacteraceae/isolamento & purificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Oxalobacteraceae/genética , Oxalobacteraceae/fisiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo , Taiwan , UbiquinonaRESUMO
BACKGROUND: Dynamic establishment of the nasal microbiota in early life influences local mucosal immune responses and susceptibility to childhood respiratory disorders. OBJECTIVE: The aim of this case-control study was to monitor, evaluate, and compare development of the nasal microbiota of infants with rhinitis and wheeze in the first 18 months of life with those of healthy control subjects. METHODS: Anterior nasal swabs of 122 subjects belonging to the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) birth cohort were collected longitudinally over 7 time points in the first 18 months of life. Nasal microbiota signatures were analyzed by using 16S rRNA multiplexed pair-end sequencing from 3 clinical groups: (1) patients with rhinitis alone (n = 28), (2) patients with rhinitis with concomitant wheeze (n = 34), and (3) healthy control subjects (n = 60). RESULTS: Maturation of the nasal microbiome followed distinctive patterns in infants from both rhinitis groups compared with control subjects. Bacterial diversity increased over the period of 18 months of life in control infants, whereas infants with rhinitis showed a decreasing trend (P < .05). An increase in abundance of the Oxalobacteraceae family (Proteobacteria phylum) and Aerococcaceae family (Firmicutes phylum) was associated with rhinitis and concomitant wheeze (adjusted P < .01), whereas the Corynebacteriaceae family (Actinobacteria phylum) and early colonization with the Staphylococcaceae family (Firmicutes phylum; 3 weeks until 9 months) were associated with control subjects (adjusted P < .05). The only difference between the rhinitis and control groups was a reduced abundance of the Corynebacteriaceae family (adjusted P < .05). Determinants of nasal microbiota succession included sex, mode of delivery, presence of siblings, and infant care attendance. CONCLUSION: Our results support the hypothesis that the nasal microbiome is involved in development of early-onset rhinitis and wheeze in infants.
Assuntos
Microbiota , Mucosa Nasal/microbiologia , Sons Respiratórios , Rinite/microbiologia , Estudos de Casos e Controles , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mucosa Nasal/imunologia , Sons Respiratórios/imunologia , Rinite/imunologia , SingapuraRESUMO
A Gram-stain-negative, rod-shaped, motile, catalase and cytochrome c oxidase-positive bacterial strain, designated S20-91T, was isolated from alpine forest soil. Growth occurred within a temperature range of 0-25 °C. Yeast extract was required for growth. Phylogenetic analysis based on 16S rRNA gene sequencing showed that strain S20-91T was related to the genus Herminiimonas and had the highest 16S rRNA gene sequence similarity to Herminiimonas arsenicoxydans ULPAs1T (96.5â%). The strain contained ubiquinone 8 as the predominant respiratory quinone and phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as the major polar lipids. The major cellular fatty acids (>10â%) were C16â:â1ω7c (55.3â%) and C16â:â0 (25.6â%). The genomic DNA G+C content was 47.6 mol%. Combined data of genomic, phylogenetic, phenotypic and chemotaxonomic analyses demonstrated that strain S20-91T represents a novel genus and species, for which the name Solimicrobium silvestre gen. nov., sp. nov. is proposed. The type strain is S20-91T (=DSM 104733T=LMG 30010).
Assuntos
Florestas , Oxalobacteraceae/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Itália , Oxalobacteraceae/genética , Oxalobacteraceae/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/químicaRESUMO
Strain 10R5-21T was isolated from lagoon sediments. Cells of strain 10R5-21T were Gram-reaction-negative, rod-shaped and motile by means of polar flagella. The strain was obligately aerobic and positive for catalase and oxidase activity. Strain 10R5-21T was able to grow at 10-37 ËC (optimum 25-30 ËC), at pH 5.0-9.0 (optimum pH 6.5-7.5) and in the presence of 0-0.5â% (w/v) NaCl (optimum 0â%). C16â:â1ω7c/C16â:â1ω6c, C16â:â0 and C12â:â0 were present as predominant (>5â%) fatty acids. Q-8 was identified as the major respiratory quinone. Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were present as major polar lipids with minor amounts of unidentified aminophospholipids and unidentified aminolipids. The genomic G+C content of strain 10R5-21T was 64.1 mol%. 16S rRNA gene sequence analysis indicated that strain 10R5-21T belongs to the genus Pseudoduganella within the family Oxalobacteraceae of the class Betaproteobacteria. Strain 10R5-21T shared 98.8â% 16S rRNA gene sequence similarity with Pseudoduganella violaceinigra YIM 31327T. DNA-DNA hybridization values between strain 10R5-21T and P. violaceinigra KACC 11669T were clearly below the 70â% threshold. Distinct morphological, biochemical, chemotaxonomic and genetic differences from previously described taxa support the classification of strain 10R5-21T as a representative of a novel species in the genus Pseudoduganella, for which the name Pseudoduganella eburnea sp. nov. is proposed. The type strain is 10R5-21T (=KEMB 563-061T=JCM 31587T).
Assuntos
Sedimentos Geológicos/microbiologia , Oxalobacteraceae/classificação , Filogenia , Microbiologia da Água , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , North Carolina , Hibridização de Ácido Nucleico , Oxalobacteraceae/genética , Oxalobacteraceae/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/químicaRESUMO
Strain KYPY9T, isolated from the Funglin Stream in Taiwan, was characterized using a polyphasic taxonomy approach. Cells of KYPY9T were Gram-staining-negative, strictly aerobic, motile by means of a single polar flagellum, rod-shaped and formed light yellow colonies. Optimal growth occurred at 20-25 °C, at pH 7 and with 0â% NaCl. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that KYPY9T represented a member of the genus Undibacterium and the sequence similarity between the 16S rRNA genes of KYPY9T and of the type strains of other species of the genus Undibacterium ranged from 94.1 to 98.0â%. The closest relatives of KYPY9T were Undibacterium seohonense SHS5-24T (98.0â%) and Undibacterium macrobrachii CMJ-9T (97.0â%). KYPY9T had summed feature 3 (C16â:â1ω7c and/or C16â:â1ω6c) and C16â:â0 as the predominant fatty acids. The major cellular hydroxy fatty acid was C10â:â0 3-OH. KYPY9T had phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as the predominant polar lipids. The polyamine profile was composed of the major compound 2-hydroxyputrescine and moderate amounts of putrescine. The major respiratory quinone was Q-8 and the DNA G+C content was 47.4 mol%. The DNA-DNA relatedness of KYPY9T with respect to Undibacterium seohonense SHS5-24T and Undibacterium macrobrachii CMJ-9T was less than 35â%. On the basis of the phylogenetic inference and phenotypic data, KYPY9T was recognized as a representative of a novel species within the genus Undibacterium. The name Undibacterium amnicola sp. nov. is proposed, with KYPY9T (=BCRC 81009T=LMG 29730T=KCTC 52442T) as the type strain.
Assuntos
Oxalobacteraceae/classificação , Filogenia , Rios/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Oxalobacteraceae/genética , Oxalobacteraceae/isolamento & purificação , Pigmentação , Putrescina/análogos & derivados , Putrescina/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Taiwan , Ubiquinona/químicaRESUMO
Family Oxalobacteraceae is known for the indicator of bacterial diversity in the environment and many of which are important beneficial bacteria. Previous studies on the taxonomic structure of family Oxalobacteraceae mostly relied on 16S rRNA gene analysis, or core-genome phylogeny of a limited number of species and resulted in taxonomic confusion within several genera. Developments in sequencing technologies have allowed more genome sequences to be obtained, enabling the revision of family Oxalobacteraceae. Here, we report a comprehensive analysis of phylogenomic trees, concatenated protein and up-to-date bacterial core gene phylogenetic trees, and genomic metrics for genus demarcation on 135 genomes of Oxalobacteraceae species to elucidate their interrelationships. Following this framework for classification of species in family Oxalobacteraceae, all the proposed genera formed monophyletic lineages in the phylogenomic trees and could also be clearly separated from others in the genomic similarity indexes of average amino acid identity, percentage of conserved proteins and core-proteome average amino acid identity.
RESUMO
Many plants and animals have symbiotic relationships with microorganisms, including bacteria. The interactions between bacteria and their hosts result in different outcomes for the host organism. The outcome can be neutral, harmful or have beneficial effects for participants. Remarkably, these relationships are not static, as they change throughout an organism's lifetime and on an evolutionary scale. One of the structures responsible for relationships in bacteria is O-antigen. Depending on the characteristics of its components, the bacteria can avoid the host's immune response or establish a mutualistic relationship with it. O-antigen is a key component in Gram-negative bacteria's outer membrane. This component facilitates interaction between the bacteria and host immune system or phages. The variability of the physical structure is caused by the genomic variability of genes encoding O-antigen synthesis components. The genes and pathways of O-polysaccharide (OPS) synthesis were intensively investigated mostly for Enterobacteriaceae species. Considering high genetic and molecular diversity of this structure even between strains, these findings may not have caught the entire variety possibly presented in non-model species. The current study presents a comparative analysis of genes associated with O-antigen synthesis in bacteria of the Oxalobacteraceae family. In contrast to existing studies based on PCR methods, we use a bioinformatics approach and compare O- antigens at the level of clusters rather than individual genes. We found that the O-antigen genes of these bacteria are represented by several clusters located at a distance from each other. The greatest similarity of the clusters is observed within individual bacterial genera, which is explained by the high variability of O-antigens. The study describes similarities of OPS genes inherent to the family as a whole and also considers individual unique cases of O-antigen genetic variability inherent to individual bacteria.
RESUMO
Bacteria of the genus Massilia often colonize extreme ecosystems, however, a detailed study of the massilias from the Antarctic environment has not yet been performed. Here, sixty-four Gram-stain-negative, aerobic, motile rods isolated from different environmental samples on James Ross Island (Antarctica) were subjected to a polyphasic taxonomic study. The psychrophilic isolates exhibited slowly growing, moderately slimy colonies revealing bold pink-red pigmentation on R2A agar. The set of strains exhibited the highest 16S rRNA gene sequence similarities (99.5-99.9%) to Massilia violaceinigra B2T and Massilia atriviolacea SODT and formed several phylogenetic groups based on the analysis of gyrB and lepA genes. Phenotypic characteristics allowed four of them to be distinguished from each other and from their closest relatives. Compared to the nearest phylogenetic neighbours the set of six genome-sequenced representatives exhibited considerable phylogenetic distance at the whole-genome level. Bioinformatic analysis of the genomic sequences revealed a high number of putative genes involved in oxidative stress response, heavy-metal resistance, bacteriocin production, the presence of putative genes involved in nitrogen metabolism and auxin biosynthesis. The identification of putative genes encoding aromatic dioxygenases suggests the biotechnology potential of the strains. Based on these results four novel species and one genomospecies of the genus Massilia are described and named Massilia rubra sp. nov. (P3094T=CCM 8692T=LMG 31213T), Massilia aquatica sp. nov. (P3165T=CCM 8693T=LMG 31211T), Massilia mucilaginosa sp. nov. (P5902T=CCM 8733T=LMG 31210T), and Massilia frigida sp. nov. (P5534T=CCM 8695T=LMG 31212T).