RESUMO
Endophytic actinomycetes encompass bacterial groups that are well known for the production of a diverse range of secondary metabolites. Vochysia divergens is a medicinal plant, common in the "Pantanal" region (Brazil) and was focus of many investigations, but never regarding its community of endophytic symbionts. During a screening program, an endophytic strain isolated from the V. divergens, was investigated for its potential to show biological activity. The strain was characterized as Microbispora sp. LGMB259 by spore morphology and molecular analyze using nucleotide sequence of the 16S rRNA gene. Strain LGMB259 was cultivated in R5A medium producing metabolites with significant antibacterial activity. The strain produced 4 chemically related ß-carbolines, and 3 Indoles. Compound 1-vinyl-ß-carboline-3-carboxylic acid displayed potent activity against the Gram-positive bacterial strains Micrococcus luteus NRRL B-2618 and Kocuria rosea B-1106, and was highly active against two human cancer cell lines, namely the prostate cancer cell line PC3 and the non-small-cell lung carcinoma cell line A549, with IC50 values of 9.45 and 24.67 µM, respectively. 1-Vinyl-ß-carboline-3-carboxylic acid also showed moderate activity against the yeast Saccharomyces cerevisiae ATCC204508, as well as the phytopathogenic fungi Phyllosticta citricarpa LGMB06 and Colletotrichum gloeosporioides FDC83.
Assuntos
Actinobacteria/metabolismo , Carbolinas/metabolismo , Carbolinas/farmacologia , Indóis/metabolismo , Indóis/farmacologia , Traqueófitas/microbiologia , Actinobacteria/classificação , Actinobacteria/isolamento & purificação , Actinobacteria/ultraestrutura , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Brasil , Carbolinas/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Indóis/química , Concentração Inibidora 50 , Estrutura Molecular , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
This study reports the characterization of the Tetrasphaera duodecadis bacteria and the techniques used therein. In order to evaluate the morphological characteristics of the T. duodecadis bacteria scanning electron microscope (SEM) was used throughout its different growth stages. These microorganisms were grown in vitamin B12 broths with 1% tryptone, 0.2% yeast extract, and 0.1% glucose. The turbidimetric method was employed for the determination of bacterial concentration and growth curve. The SEM results show small agglomerates of 0.8 ± 0.05 µm during the lag phase, and rod-like shapes during the exponential phase with similar shapes in the stationary phase.
Assuntos
Actinobacteria/ultraestrutura , Actinobacteria/crescimento & desenvolvimento , Biomassa , Meios de Cultura/química , Microscopia Eletrônica de Varredura , EspectrofotometriaRESUMO
Bacteria associated with the parthenogenetic troglobiont sand fly Deanemyia maruaga were characterized by sequencing cloned 16S rDNA PCR products. Eleven novel partial 16S rDNA sequences, with varying degrees of similarity to Actinobacteria, were identified. None of the sequences identified had homology to those known from parthenogenesis-inducing bacteria.(AU)
Assuntos
Animais , Fezes/parasitologia , Reação em Cadeia da Polimerase , Actinobacteria/ultraestrutura , Quirópteros/classificaçãoRESUMO
O solo é um ecossistema complexo, dinâmico e difícil de ser estudado, a quantidade e diversidade de micro-organismos do solo são imensas. A microbiota do solo é caracterizada pela abundância e diversidade. A atividade microbiana é utilizada como uma maneira de melhor entender os processos de mineralização e observar mais profundamente a intensidade dos fluxos de energia no solo. A fertilidade natural do solo depende, portanto, da dinâmica de matéria orgânica e ciclagem de nutrientes, os quais são catalizados pela biomassa microbiana do solo. Dentre as bactérias existentes no solo, encontram-se as autotróficas, as heterotróficas, as aeróbias, as anaeróbias, as fixadoras de nitrogênio, nitrificantes e desnitrificantes, actinomicetos, entre outras. Estudos ecológicos das populações de actinomicetos são de extrema importância, visto que esses micro-organismos se destacam pela possibilidade de sintetizar vitaminas, substâncias inibidoras da atividade enzimática e antibióticos. A determinação das densidades populacionais na comunidade microbiana dos solos é importante, tanto na identificação de fatores que influenciam o equilíbrio microbiológico dos solos, como na caracterização das relações entre grupos e espécies de microrganismos. Portanto, é de grande relevância a quantificação das bactérias em geral e actinomicetos presentes no solo para que se possa inferir sobre a fertilidade do solo. Estudos dessa natureza podem fornecer subsídios para programas de conservação de áreas florestadas e recuperação de áreas degradadas.(AU)
Soil is a complex, dynamic and hard-to-study ecosystem due to the immense quantity and diversity of micro-organisms. Soil microbiota is characterized by abundance and diversity. Microbial activity is used as a way to better understand the mineralization processes and have an in-depth visualization of the intensity of energy flows in the soil. The natural fertility of the ground depends, therefore, on the dynamics of organic matter and nutrient recycling, which are catalyzed by the soil microbial biomass. Among the bacteria on the soil, it is possible to find autotrophic, heterotrophic, aerobial, anaerobial, nitrogen-fixing, nitrifying and denitrifying, actinomycetes, and others. Ecological studies of actinomycete populations are of extreme importance, since these microorganisms are outstanding due to their ability to synthesize vitamins, enzymatic activity inhibitors and antibiotics. Determining microbial population densities is important both in the identification of factors which influence the microbiological balance in the soil and in the characterization of relationships among groups and species of microorganisms. Therefore, the quantification of bacteria in general and actinomycetes from the soil is of great importance, since it may enable inferences about soil fertility. Studies of this nature may provide subsidies for conservational programs in forested areas and degraded areas in recovery processes.(AU)
El suelo es un ecosistema complejo, dinámico y difícil de ser estudiado, ya que la cantidad y diversidad de microorganismos del suelo son inmensas. La microbiota del suelo se caracteriza por la abundancia y diversidad. La actividad microbiana es utilizada como una forma de entender mejor los procesos de mineralización y visualizar más profundamente la intensidad de los flujos de energía en el suelo. La fertilidad natural del suelo depende, por lo tanto, de la dinámica de materia orgánica y ciclo de nutrientes, los cuales son catalizados por la biomasa microbiana del suelo. Entre las bacterias existentes en el suelo, se encuentran los autótrofos, heterótrofos, aérobicos, anaeróbicos, fijadoras de nitrógeno, nitrificadoras y denitrificadoras, actinomicetos, entre otros. Estudios ecológicos de las poblaciones de actinomicetos son de extrema importancia ya que esos microorganismos se destacan por la posibilidad de sintetizar vitaminas, sustancias inhibidoras de la actividad enzimática y antibióticos. La determinación de las densidades poblacionales en la comunidad microbiana de los suelos es importante, tanto en la identificación de factores que influencian el equilibrio microbiológico de los suelos, como la caracterización de las relaciones entre grupos y especies de microorganismos. Por lo tanto, es de gran importancia la cuantificación de las bacterias en general y actinomicetos presentes en el suelo para que se pueda inferir sobre la fertilidad del suelo. Estudios de esta naturaleza pueden proporcionar subsidios para programas de conservación de áreas forestales y recuperación de áreas degradadas.(AU)
Assuntos
Animais , População , Solo , Bactérias/ultraestrutura , Actinobacteria/ultraestruturaRESUMO
Microbial biodiversity provides an increasingly important source of medically and industrially useful compounds. We have isolated 14 actinomycete species from a collection of approximately 300 plant stem samples from the upper Amazonian rainforest in Peru. All of the cultured isolates produce substances with inhibitory activity directed at a range of potential fungal and bacterial pathogens. For some organisms, this activity is very broad in spectrum while other organisms show specific activity against a limited number of organisms. Two of these organisms preferentially inhibit bacterial test organisms over eukaryotic organisms. rDNA sequence analysis indicates that these organisms are not equivalent to any other cultured deposits in GenBank. Our results provide evidence of the untapped biodiversity in the form of biologically active microbes present within the tissues of higher plants.