RESUMEN
Two Gram-stain-positive bacterial strains, EXRC-4A-4T and RC-2-3T, were isolated from soil samples collected at Union Glacier, Antarctica. Based on 16S rRNA gene sequence similarity, strain EXRC-4A-4T was identified as belonging to the genus Rhodococcus, and strain RC-2-3T to the genus Pseudarthrobacter. Further genomic analyses, including average nucleotide identity and digital DNA-DNA hybridization, suggested that these strains represent new species. Strain EXRC-4A-4T exhibited growth at temperatures ranging from 4 to 28 °C (optimum between 20 and 28 °C), at pH 5.0-9.0 (optimum, pH 6.0), and in the presence of 0-5.0% NaCl (optimum between 0 and 1% NaCl). Strain RC-2-3T grew at 4-28 °C (optimum growth at 28 °C), pH 6.0-10 (optimum, pH 7.0) and in the presence of 0-5.0% NaCl (optimum, 1% NaCl). The fatty acid profile of EXRC-4A-4T was dominated by C17:1 ω-7, while that of RC-2-3T was dominated by anteiso-C15â:â0. The draft genome sequences revealed a DNA G+C content of 64.6 mol% for EXRC-4A-4T and 65.8 mol% for RC-2-3T. Based on this polyphasic study, EXRC-4A-4T and RC-2-3T represent two novel species within the genera Rhodococcus and Pseudarthrobacter, respectively. We propose the names Rhodococcus navarretei sp. nov. and Pseudarthrobacter quantipunctorum sp. nov. The type strains are Rhodococcus navarretei EXRC-4A-4T and Pseudarthrobacter quantipunctorum RC-2-3T. These strains have been deposited deposited in the CChRGM and BCCM/LMG culture collections with entry numbers RGM 3539/LMG 33621 and RGM 3538/LMG 33620, respectively.
Asunto(s)
Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S , Rhodococcus , Análisis de Secuencia de ADN , Microbiología del Suelo , Rhodococcus/genética , Rhodococcus/clasificación , Rhodococcus/aislamiento & purificación , Rhodococcus/metabolismo , ARN Ribosómico 16S/genética , Regiones Antárticas , ADN Bacteriano/genética , Cubierta de Hielo/microbiología , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Actinomycetales/clasificación , Actinomycetales/metabolismoRESUMEN
An antibiotic-producing actinobacterium, designated isolate B375T, was isolated from marine sponge Glodia corticostylifera collected from Praia Guaecá, São Paulo, Brazil (23°49S; 45°25W), and its taxonomic position established using data from a polyphasic study. The organism showed a combination of morphological, physiological, biochemical and chemotaxonomic characteristics consistent with its classification in the genus Williamsia. Comparative 16S rRNA gene sequence analysis indicated that the strain B375T was most closely related to Williamsia serinedens DSM 45037T and Williamsia spongiae DSM 46676T and having 99.43% and 98.65% similarities, respectively, but was distinguished from these strains by a low level of DNA-DNA relatedness (53.2-63.2%) and discriminatory phenotypic properties. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and N-glycolated muramic acid residues present in the wall cells. The cells contained C16:0 (23.3%), C18:0 10-methyl (23.2%) and C18:1 ω9c (21.6%) as the major cellular fatty acids. The strain B375T inhibited growing of Staphylococcus aureus and Colletotrichum gloeosporioides strains and was considered a producer of antimicrobial compounds. Based on the data obtained, the isolate B375T (= CBMAI 1090T = DSM 46677T) should, therefore, be classified as the type strain of a novel species of the genus Williamsia, for which the name Williamsia aurantiacus sp. nov. is proposed.
Asunto(s)
Actinomycetales/aislamiento & purificación , Actinomycetales/metabolismo , Antibacterianos/metabolismo , Colletotrichum/crecimiento & desarrollo , Poríferos/microbiología , Staphylococcus aureus/crecimiento & desarrollo , Actinomycetales/genética , Animales , Técnicas de Tipificación Bacteriana , Brasil , ADN Bacteriano/genética , Ácidos Grasos/análisis , Ácidos Murámicos/análisis , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Granulomatous lobular mastitis is a rare disease whose origin is still unknown and shows an increase in its frequency. Morphological, microbiological, and molecular biology studies have linked this disease to lipophilic and fastidious corynebacteria, suggesting its possible infectious etiology. This series describes and reviews in detail the distinctive morphological characteristics of the bacteria present in the granulomas of this disease, the usefulness of histochemical techniques for their identification, and our proposal for a tissue quantification score for the bacteria. The MacCallum-Goodpasture method of Gram's stain turned out to be the gold standard for examination, but we also highlight the efficiency of hematoxylin and eosin stain when it is exhaustively examined as well as the Grocott stain to evaluate the bacterial pleomorphism method, which is often underutilized.
Asunto(s)
Infecciones por Actinomycetales/diagnóstico , Actinomycetales/aislamiento & purificación , Mama/patología , Mastitis Granulomatosa/diagnóstico , Infecciones por Actinomycetales/microbiología , Infecciones por Actinomycetales/patología , Adulto , Anciano , Biopsia , Mama/microbiología , Colorantes/química , Eosina Amarillenta-(YS)/química , Femenino , Violeta de Genciana , Mastitis Granulomatosa/microbiología , Mastitis Granulomatosa/patología , Hematoxilina/química , Humanos , Persona de Mediana Edad , Fenazinas , Adulto JovenRESUMEN
A novel actinomycete, designated strain NEAU-mq3T, was isolated from the rhizosphere soil of a rubber tree (Hevea brasiliensis Muell. Arg) collected from Xianglu Mountain in Heilongjiang Province, north-east China, and characterized by using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the organism should be assigned to the genus Sphaerisporangium and that it forms a monophyletic clade with its closest relatives 'Sphaerisporangium dianthi' NEAU-CY18T (99.2â% 16S rRNA gene sequence similarity) and Sphaerisporangium cinnabarinum JCM 3291T (98.8â%). Morphological and chemotaxonomic properties of strain NEAU-mq3T were also consistent with the description of the genus Sphaerisporangium. The whole-cell sugars were madurose, mannose, ribose and glucose. The menaquinones were MK-9(H2), MK-9(H4), MK-9(H0) and MK-9(H6). The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol mannoside, an unidentified polar lipid and an unidentified phospholipid. The major fatty acids were identified as iso-C16â:â0, 10-methyl C17â:â0, C16â:â1ω7c and C17â:â1ω7c. DNA-DNA hybridization experiments and phenotypic tests were carried out between strain NEAU-mq3T and its most closely related strains, which further clarified their relatedness and demonstrated that NEAU-mq3T could be distinguished from these strains. Therefore, it is concluded that strain NEAU-mq3T represents a novel species of the genus Sphaerisporangium, for which the name Sphaerisporangium rhizosphaerae sp. nov. is proposed. The type strain is NEAU-mq3T (=CGMCC 4.7429T=JCM 32389T).
Asunto(s)
Actinomycetales/clasificación , Hevea/microbiología , Filogenia , Rizosfera , Microbiología del Suelo , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , Pared Celular/química , China , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Peptidoglicano/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
A polyphasic study was undertaken to establish the taxonomic status of a Blastococcus strain isolated from an extreme hyper-arid Atacama Desert soil. The isolate, strain P6T, was found to have chemotaxonomic and morphological properties consistent with its classification in the genus Blastococcus. It was shown to form a well-supported branch in the Blastococcus 16S rRNA gene tree together with the type strains of Blastococcus capsensis and Blastococcus saxobsidens and was distinguished from the latter, its close phylogenetic neighbour, by a broad range of phenotypic properties. The draft genome sequence of isolate P6T showed 84.6â% average nucleotide identity, 83.0â% average amino acid identity and a digital DNA-DNA hybridisation value of 27.8â% in comparison with the genome sequence of B. saxobsidens DSM 44509T, values consistent with its assignment to a separate species. Based on these data it is proposed that isolate P6T (NCIMB 15090T=NRRL B-65468T) be assigned to the genus Blastococcus as Blastococcus atacamensis sp. nov. Analysis of the whole genome sequence of B. atacamensis P6T, with 3778 open reading frames and a genome size of 3.9 Mb showed the presence of genes and gene clusters that encode for properties that reflect its adaptation to the extreme environmental conditions that prevail in Atacama Desert soils.
Asunto(s)
Actinomycetales/clasificación , Clima Desértico , Filogenia , Microbiología del Suelo , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
A novel actinomycete, designated strain NEAU-mq18T, was isolated from the rhizosphere soil of a rubber tree (Hevea brasiliensis Muell. Arg) collected from Xianglu Mountain in Heilongjiang Province, northeast China, and subjected to a polyphasic taxonomic study. The 16S rRNA gene sequence analysis showed that the isolate belongs to the genus Nonomuraea with high sequence similarity to Nonomuraea guangzhouensis NEAU-ZJ3T (98.5%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain clusters phylogenetically with N. guangzhouensis NEAU-ZJ3T and Nonomuraea glycinis NEAU-BB2C19T. Moreover, key chemotaxonomic properties including the major menaquinones, fatty acid composition and phospholipid profile also confirmed the affiliation of the strain to the genus Nonomuraea. However, some physiological, morphological and biochemical properties, and low DNA-DNA relatedness values, enabled the strain to be differentiated from closely related species of the genus Nonomuraea. Thus, strain NEAU-mq18T is concluded to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea rhizosphaerae sp. nov. is proposed. The type strain is NEAU-mq18T (=CGMCC 4.7431T=DSM 105761T).
Asunto(s)
Actinomycetales/aislamiento & purificación , Microbiología del Suelo , Actinomycetales/clasificación , Actinomycetales/genética , Actinomycetales/metabolismo , Técnicas de Tipificación Bacteriana , China , ADN Bacteriano/genética , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Hevea/crecimiento & desarrollo , Filogenia , ARN Ribosómico 16S/genética , RizosferaRESUMEN
Eleven actinobacterial strains were isolated from a rock sample collected in the Atacama Desert. Molecular typing by BOX-PCR divided the strains into three clusters and showed that, although very similar, they were not clones. Three strains, ATK01, ATK03T and ATK17, each representing one of the defined BOX clusters, were chosen for further characterization. Phylogenetic analysis indicated that the strains were related to the genus Pseudonocardia and were recovered in a cluster together with Pseudonocardia bannensis YIM 63101T and Pseudonocardia xinjiangensis AS 4.1538T. Chemotaxonomic analyses confirmed their affiliation to the genus Pseudonocardia but differences were found between the new strains and their closest phylogenetic relatives. Physiological and fatty acid analyses also revealed differences between these strains and their phylogenetic neighbours supporting their status as a distinct species. Based on the overall data, it is proposed that strains ATK01, ATK03T and ATK17 represent a novel species of the genus Pseudonocardia for which the name Pseudonocardia nigra sp. nov. is proposed (type strain ATK03T=DSM 104088T=CECT 9183T).
Asunto(s)
Actinomycetales/clasificación , Clima Desértico , Filogenia , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Abstract Dietzia sp. 111N12-1, isolated from the seawater of South China Sea, shows strong petroleum hydrocarbons degradation activity. Here, we report the draft sequence of approximately 3.7-Mbp genome of this strain. To the best of our knowledge, this is the first genome sequence of Dietzia strain isolated from the sea. The genome sequence may provide fundamental molecular information on elucidating the metabolic pathway of hydrocarbons degradation in this strain.
Asunto(s)
Agua de Mar/microbiología , Actinomycetales/aislamiento & purificación , Actinomycetales/genética , Genoma Bacteriano , Hidrocarburos/metabolismo , Filogenia , Biodegradación Ambiental , Actinomycetales/clasificación , Actinomycetales/metabolismo , Petróleo/metabolismo , Secuencia de Bases , ChinaRESUMEN
Dietzia sp. 111N12-1, isolated from the seawater of South China Sea, shows strong petroleum hydrocarbons degradation activity. Here, we report the draft sequence of approximately 3.7-Mbp genome of this strain. To the best of our knowledge, this is the first genome sequence of Dietzia strain isolated from the sea. The genome sequence may provide fundamental molecular information on elucidating the metabolic pathway of hydrocarbons degradation in this strain.
Asunto(s)
Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Genoma Bacteriano , Hidrocarburos/metabolismo , Agua de Mar/microbiología , Actinomycetales/clasificación , Actinomycetales/metabolismo , Secuencia de Bases , Biodegradación Ambiental , China , Petróleo/metabolismo , FilogeniaRESUMEN
A novel actinobacterium, designated isolate B138T, was isolated from the marine sponge, Amphimedon viridis, which was collected from Praia Guaecá (São Paulo, Brazil), and its taxonomic position was established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological characteristics consistent with its classification in the genus Williamsia and it formed a distinct phyletic line in the Williamsia 16S rRNA gene tree. It was most closely related to Williamsia serinedens DSM 45037T and Williamsia deligens DSM 44902T (99.0â% 16S rRNA gene sequence similarity) and Williamsia maris DSM 44693T (97.5â% 16S rRNA gene sequence similarity), but was distinguished readily from these strains by the low DNA-DNA relatedness values (62.3-64.4â%) and by the discriminatory phenotypic properties. Based on the data obtained, the isolate B138T (=CBMAI 1094T=DSM 46676T) should be classified as the type strain of a novel species of the genus Williamsia, for which the name Williamsia spongiae sp. nov. is proposed.
Asunto(s)
Actinomycetales/clasificación , Filogenia , Poríferos/microbiología , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , Brasil , ADN Bacteriano/genética , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Mycetoma is a chronic granulomatous, subcutaneous disease endemic in tropical and subtropical countries. It is currently a health problem in rural areas of Africa, Asia and South America. Nine cases of mycetoma were analysed in a retrospective study. All isolates were identified by morphological features. The level of species identification was reached by molecular tools. Definitive identification of fungi was performed using sequence analysis of the ITS of the ribosomal DNA region and the ribosomal large-subunit D1/D2. Identification of actinomycetes was accomplished by the 16S rRNA gene sequence. Six unusual clinical isolates were identified: Aspergillus ustus, Cyphellophora oxyspora, Exophiala oligosperma, Madurella pseudomycetomatis, Nocardia farcinica and Nocardia wallacei. The prevalence of mycetoma in Venezuela remains unknown. This study represents the first report in the literature of mycetoma caused by unusual pathogens identified by molecular techniques.
Asunto(s)
Actinomycetales/genética , ADN Espaciador Ribosómico , ADN Ribosómico/genética , Hongos/genética , Micetoma/microbiología , ARN Ribosómico 16S/genética , Actinobacteria/genética , Actinomycetales/aislamiento & purificación , Adolescente , Adulto , Exophiala/genética , Exophiala/aislamiento & purificación , Femenino , Hongos/clasificación , Hongos/aislamiento & purificación , Humanos , Madurella/genética , Madurella/aislamiento & purificación , Masculino , Persona de Mediana Edad , Micetoma/tratamiento farmacológico , Micetoma/epidemiología , Micetoma/patología , Técnicas de Tipificación Micológica , Nocardia/genética , Nocardia/aislamiento & purificación , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Venezuela/epidemiologíaRESUMEN
The genus Microbispora has been considered difficult to define taxonomically. While 16S rRNA gene analysis is required to determine phylogenetic relationships among species in this genus, most 16S rRNA gene-based phylogenetic tree topologies are not reliable. The genus Microbispora currently contains eight species along with six reclassified species (Microbispora chromogenes, Microbispora diastatica, Microbispora parva, Microbispora indica, Microbispora karnatakensis, Microbispora rosea) and Microbispora rosea subsp. aerata, a taxon composed of three further reclassified species (Microbispora aerata, Microbispora thermodiastatica, and Microbispora thermorosea). 16S rRNA, 23S rRNA, gyrB, and rpoB gene sequences were obtained for the type strains of Microbispora species, and eleven endophytic isolates from a Brazilian medicinal plant, Vochysia divergens. Using the concatenated sequence, most Microbispora type strains could be distinguished with high probability support. Based on these analyses, we propose that five of the species reclassified within the subspecies of M. rosea (M. chromogenes, M. karnatakensis, M. parva, M. aerata and M. thermorosea) are distinct from M. rosea and so should be retained as distinct species. The concatenated 16S-gyrB-rpoB gene phylogenic tree had significant probability support and topology. We propose the use of concatenated 16S-gyrB-rpoB gene sequences to determine phylogenetic relationships within the genus Microbispora. We also suggest that strains sharing >98.1 % 16S-gyrB-rpoB gene sequences similarity be defined as a single species, based on results from this analysis. Seven of the strains isolated from V. divergens were not related to any previously described Microbispora species.
Asunto(s)
Actinomycetales/clasificación , Actinomycetales/genética , Girasa de ADN/genética , ARN Ribosómico 16S/genética , Actinomycetales/aislamiento & purificación , Proteínas Bacterianas/genética , Brasil , ADN Bacteriano/genética , ADN Ribosómico/genética , ARN Polimerasas Dirigidas por ADN/genética , Endófitos , Ácidos Grasos/análisis , Tipificación de Secuencias Multilocus/métodos , Filogenia , Análisis de Secuencia de ADN , Tracheophyta/microbiologíaRESUMEN
Actinomycetes bacteria associated with leafcutter ants produce secondary metabolites with antimicrobial properties against Escovopsis, a fungus specialized in attacking the gardens of fungus-growing ants, which denies the ants their food source. Because previous studies have used fungi isolated from fungus gardens but not from ant integument, the aims of the present study were to isolate actinomycetes associated with the cuticle of the Acromyrmex spp. and to quantify their inhibition abilities against the filamentous fungal species carried by these ants. The results demonstrated that actinomycetes had varied strain-dependent effects on several filamentous fungal species in addition to antagonistic activity against Escovopsis. The strain isolated from Acromyrmex balzani was identified as a Streptomyces species, whereas the remaining isolates were identified as different strains belonging to the genus Pseudonocardia. These findings corroborate the hypothesis that actinomycetes do not act specifically against Escovopsis mycoparasites and may have the ability to inhibit other species of pathogenic fungi.
Asunto(s)
Actinobacteria/aislamiento & purificación , Actinobacteria/fisiología , Hormigas/microbiología , Hongos/fisiología , Actinobacteria/genética , Actinobacteria/metabolismo , Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Actinomycetales/metabolismo , Animales , Antifúngicos/farmacología , Hormigas/fisiología , Hongos/crecimiento & desarrollo , Hongos/aislamiento & purificación , Hypocreales/efectos de los fármacos , Filogenia , Reacción en Cadena de la Polimerasa/métodos , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Streptomyces/clasificación , Streptomyces/metabolismo , Streptomyces/fisiología , SimbiosisRESUMEN
Microbacterium sp. CGR1 (RGM2230) is an isolate from the Atacama Desert that displays a wide pH, salinity and temperature tolerance. This strain exhibits riboflavin overproducer features and traits for developing an environmental arsenic biosensor. Here, we report the complete genome sequence of this strain, which represents the first genome of the genus Microbacterium sequenced and assembled in a single contig. The genome contains 3,634,864bp, 3299 protein-coding genes, 45 tRNAs, six copies of 5S-16S-23S rRNA and a high genome average GC-content of 68.04%.
Asunto(s)
Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Adaptación Fisiológica/genética , Clima Desértico , Genoma Bacteriano , Secuencia de Bases , ChileRESUMEN
A novel marine actinomycete, designated B374(T), was isolated from a marine sponge, Glodia corticostylifera, which was collected from São Paulo, Brasil. The taxonomic position of B374(T) was established by using data derived from a polyphasic approach. The organism showed a combination of chemotaxonomic and morphological characteristics consistent with its classification in the genus Marmoricola and it formed a distinct phyletic line in the clade of the genus Marmoricola, based on 16S rRNA gene sequences. Strain B374(T) was most closely related to Marmoricola aequoreus SST-45(T) (98.5% 16S rRNA gene sequence similarity), but was distinguished from this strain and from the other type strains of species of the genus Marmoricola on the basis of a combination of phenotypic properties. The data obtained, therefore, indicates that isolate B374(T) ( = CBMAI 1089(T) = DSM 28169(T)) should be classified as a novel species of the genus Marmoricola, for which the name Marmoricola aquaticus sp. nov. is proposed.
Asunto(s)
Actinomycetales/clasificación , Filogenia , Poríferos/microbiología , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Animales , Composición de Base , Brasil , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Strain SB026T was isolated from Brazilian rainforest soil and its taxonomic position established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological features consistent with its classification in the genus Amycolatopsis and formed a branch in the Amycolatopsis 16S rRNA gene tree together with Amycolatopsis bullii NRRL B-24847T, Amycolatopsis plumensis NRRL B-24324T, Amycolatopsis tolypomycina DSM 44544T and Amycolatopsis vancoresmycina NRRL B-24208T. It was related most closely to A. bullii NRRL B-24847T (99.0 % 16S rRNA gene sequence similarity), but was distinguished from this strain by a low level of DNA-DNA relatedness (~46 %) and discriminatory phenotypic properties. Based on the combined genotypic and phenotypic data, it is proposed that the isolate should be classified in the genus Amycolatopsis as representing a novel species, Amycolatopsis rhabdoformis sp. nov. The type strain is SB026T (â= CBMAI 1694T = CMAA 1285T = NCIMB 14900T).
Asunto(s)
Actinomycetales/clasificación , Bosques , Filogenia , Microbiología del Suelo , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Bacterias Aerobias/genética , Técnicas de Tipificación Bacteriana , Brasil , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Suelo , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
Attine ants maintain an association with antibiotic-producing Actinobacteria found on their integuments. Evidence supports these bacteria as auxiliary symbionts that help ants to defend the fungus gardens against pathogens. Using Pseudonocardia strains isolated from Trachymyrmex ants, we tested whether the inhibitory capabilities of such strains are restricted to Escovopsis parasites that infect gardens of this ant genus. Twelve Pseudonocardia strains were tested in in vitro bioassays against Escovopsis strains derived from fungus gardens of Trachymyrmex (n = 1) and leaf-cutting ants (n = 3). Overall, significant differences were observed in the mycelial growth among each Escovopsis strain in the presence of Pseudonocardia. Particularly, Escovopsis from Acromyrmex and Trachymyrmex were the most inhibited strains in comparison to Escovopsis isolated from Atta. This result suggests that Pseudonocardia isolated from Trachymyrmex possibly secrete antimicrobial compounds effective against diverse Escovopsis strains. The fact that Trachymyrmex ants harbour Pseudonocardia strains with broad spectrum of activity and its defensive role on attine gardens are discussed.
Asunto(s)
Actinomycetales/aislamiento & purificación , Actinomycetales/fisiología , Antibiosis , Hormigas/microbiología , Hypocreales/crecimiento & desarrollo , Simbiosis , Animales , Bioensayo , Micelio/crecimiento & desarrolloRESUMEN
After chloroform fumigating an arable soil, the relative abundance of phylotypes belonging to only two phyla (Actinobacteria and Firmicutes) and two orders [Actinomycetales and Bacillales (mostly Bacillus)] increased in a subsequent aerobic incubation, while it decreased for a wide range of bacterial groups. It remained to be seen if similar bacterial groups were affected when an extreme alkaline saline soil was fumigated. Soil with electrolytic conductivity between 139 and 157 dS m(-1), and pH 10.0 and 10.3 was fumigated and the bacterial community structure determined after 0, 1, 5 and 10 days by analysis of the 16S rRNA gene, while an unfumigated soil served as control. The relative abundance of the Firmicutes increased in the fumigated soil (52.8%) compared to the unfumigated soil (34.2%), while that of the Bacteroidetes decreased from 16.2% in the unfumigated soil to 8.8% in the fumigated soil. Fumigation increased the relative abundance of the genus Bacillus from 14.7% in the unfumigated soil to 25.7%. It was found that phylotypes belonging to the Firmicutes, mostly of the genus Bacillus, were dominant in colonizing the fumigated alkaline saline as found in the arable soil, while the relative abundance of a wide range of bacterial groups decreased.
Asunto(s)
Actinomycetales/aislamiento & purificación , Bacillus/aislamiento & purificación , Fumigación , Microbiota , Microbiología del Suelo , Actinomycetales/efectos de los fármacos , Actinomycetales/genética , Álcalis/farmacología , Bacillus/efectos de los fármacos , Bacillus/genética , Cloroformo/farmacología , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
A Gram-reaction-positive bacterial isolate, designated Tü 6233(T), with rudimentary, coral-pink vegetative mycelium that formed neither aerial mycelium nor spores, was isolated from a Brazilian soil sample. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. Cell-wall hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose as the diagnostic sugar. The major fatty acids were iso-C(16â:â0), iso-C(15â:â0) and C(17â:â1)ω8c and the predominant menaquinone was MK-9(H4). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol, an unknown glycophospholipid and an unknown phospholipid. The DNA G+C content of the strain was 75.4 mol%. The 16S rRNA gene sequence identity with members of the genus Geodermatophilus was 94.2-98.7%. Based on phenotypic, chemotaxonomic and phylogenetic data, strain Tü 6233(T) is proposed to represent a novel species, Geodermatophilus brasiliensis sp. nov., with the type strain Tü 6233(T) (â=âDSM 44526(T)â=âCECT 8402(T)).