RESUMO
In recent years, the search for natural plant products to fight viral diseases has been increasing. In this work, two Spondias species, namely S. mombin and S. tuberosa, found in Ceará state (Brazil), and their main phenolic components were evaluated against dengue virus. In vitro antiviral tests were performed against type-2 dengue virus by the MTT method and standard cytopathic effect reduction assay in C6/36 cells. Cytotoxicity was also evaluated by MTT. The presence of phenolic compounds quercetin, rutin, and ellagic acid in plant extracts was characterized by HPLC analysis. Both Spondias species extracts and components were nontoxic to the cells whereas rutin and quercetin displayed relevant antiviral activity with IC50 of 362.68 µg/mL and 500 µg/mL, respectively.
Assuntos
Animais , Antivirais , Dengue , FenóisRESUMO
A dibenzothiophene (DBT)-degrading bacterial strain able to utilize carbazole as the only source of nitrogen was identified as Gordonia sp. F.5.25.8 due to its 16S rRNA gene sequence and phenotypic characteristics. Gas chromatography (GC) and GC-mass spectroscopy analyses showed that strain F.5.25.8 transformed DBT into 2-hydroxybiphenyl (2-HBP). This strain was also able to grow using various organic sulfur or nitrogen compounds as the sole sulfur or nitrogen sources. Resting-cell studies indicated that desulfurization occurs either in cell-associated or in cell-free extracts of F.5.25.8. The biological responses of F.5.25.8 to a series of mutagens and environmental agents were also characterized. The results revealed that this strain is highly tolerant to DNA damage and also refractory to induced mutagenesis. Strain F.5.25.8 was also characterized genetically. Results showed that genes involved in desulfurization (dsz) are located in the chromosome, and PCR amplification was observed with primers dszA and dszB designed based on Rhodococcus genes. However, no amplification product was observed with the primer based on dszC.
Assuntos
Carbazóis/metabolismo , Bactéria Gordonia/classificação , Bactéria Gordonia/metabolismo , Tiofenos/metabolismo , Biotecnologia , Meios de Cultura , Genes de RNAr , Bactéria Gordonia/genética , Bactéria Gordonia/crescimento & desenvolvimento , Nitrogênio/metabolismo , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Enxofre/metabolismoRESUMO
AIMS: To develop a PCR detection method, which could be used for the detection of Paenibacillus macerans in environmental samples or to help the identification of strains suspected to belong to this species. METHODS AND RESULTS: Primers specific for P. macerans were developed based on the 16S rRNA gene sequence and were evaluated by PCR performed with genomic DNA from other Paenibacillus, other bacteria and DNA from soil as templates. The primers were shown to be specific for P. macerans strains and to amplify a 981-bp amplicon. Vegetative cells of P. macerans LMD 24.10T were tracked in Cerrado soil in 24-h experiments and PCR allowed the detection of 103 introduced cells per gram of dry soil. CONCLUSIONS: This PCR detection method was adequate to assess the presence of P. macerans in Cerrado soil. SIGNIFICANCE AND IMPACT OF THE STUDY: It can also be used after culturing to rapid confirm the identity of isolates suspected to belong to P. macerans.
Assuntos
Bacillus/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/análise , Microbiologia do Solo , Animais , Bacillus/genética , Bacillus/patogenicidade , DNA Bacteriano/genética , DNA Ribossômico/análise , RNA Bacteriano/análiseRESUMO
AIMS: To evaluate the genetic diversity within the species Paenibacillus polymyxa. METHODS: Southern hybridization was performed on 102 strains of P. polymyxa using DNA from the phage IPy1 as a probe. RESULTS: All 102 strains hybridized to phage IPy1 DNA. Data from different hybridization patterns obtained were used to construct a dendrogram in which 53 genotypic groups were split into two main clusters. One cluster contained strains from the rhizospheres of sorghum and maize planted in Cerrado soil, Brazil, and the majority of strains received from two culture collections. The other cluster contained strains isolated from different Brazilian soils and rhizospheres and strains deposited in a third culture collection. SIGNIFICANCE AND IMPACT OF THE STUDY: The approach used in this study appears to be a new and a very useful tool to study the diversity within this species.
