RESUMO
The use of native strains of microorganisms from soils is an excellent option for bioremediation. To our knowledge, until now there has been no other group working on the isolation of Actinobacteria from contaminated soils in Mexico. In this study, samples of soils close to areas with oil activity in the State of Veracruz, Mexico, were inoculated for the isolation of Actinobacteria. The strains isolated were characterized morphologically, and the concentrations of NaCl and pH were determined for optimal growth. Strain selection was performed by the detection of a phylogenetic marker for Actinobacteria located at the 23S rRNA gene, followed by species identification by sequencing the 16S rRNA gene. Several haloalkalitolerant Actinobacteria were isolated and identified as: Kocuria rosea, K. palustris, Microbacterium testaceum, Nocardia farcinica and Cellulomonas denverensis. Except for C. denverensis, the biomass of all strains increased in the presence of anthracene. The strains capacity to metabolize anthracene (at 48 h), determined by fluorescence emission, was in the range of 46-54%. During this time, dihydroxy aromatic compounds formed, characterized by attenuated total reflectance Fourier transform infrared spectroscopy bands of 1205 cm-1 and 1217 cm-1. Those Actinobacteria are potentially useful for the bioremediation of saline and alkaline environments contaminated with polycyclic aromatic hydrocarbon compounds. [Int Microbiol 2016; 19(1):15-26].
Assuntos
Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Antracenos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , México , Filogenia , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , SoloRESUMO
Polycyclic aromatic hydrocarbons (PAHs) are compounds that can be quantified by fluorescence due to their high quantum yield. Haloalkalitolerant bacteria tolerate wide concentration ranges of NaCl and pH. They are potentially useful in the PAHs bioremediation of saline environments. However, it is known that salinity of the sample affects fluorescence signal regardless of the method. The objective of this work was to carry out a comparative study based on the sensitivity, linearity, and detection limits of the excitation, emission, and synchronous fluorescence methods, during the quantification of the residual anthracene concentration from the following haloalkalitolerant actinomycetes cultures Kocuria rosea, Kocuria palustris, Microbacterium testaceum, and 4 strains of Nocardia farcinica, in order to establish the proper fluorescence method to study the PAHs biodegrading capacity of haloalkalitolerant actinobacteria. The study demonstrated statistical differences among the strains and among the fluorescence methods regarding the anthracene residual concentration. The results showed that excitation and emission fluorescence methods performed very similarly but sensitivity in excitation fluorescence is slightly higher. Synchronous fluorescence using Δλ = 150 nm is not the most convenient method. Therefore we propose the excitation fluorescence as the fluorescence method to be used in the study of the PAHs biodegrading capacity of haloalkalitolerant actinomycetes.
RESUMO
Hospital wastewater is an important source of emerging contaminants. Recent studies emphasize the importance of assessing the effects of mixtures of contaminants rather than environmental risk of their individual components, as well as the determination of intrinsic toxicity of wastewater. Mixtures of pollutants has possible interactions that have notable environmental side effects. The aim of this study is an attempt to characterize biomarkers in Cyprinus carpio related to the exposure to a complex mixture of contaminants found in hospital wastewater. Results of a particular hospital effluent show the presence of traces of heavy metals, high chlorine concentration and emerging contaminants such as non-steroidal anti-inflammatory drugs. The LC50 was of 5.49 % at 96 h. The cytotoxic, genotoxic and apoptotic biomarkers increase when fishes were exposed to wastewater (1/10 CL50) from hospital wastewater. This study emphasizes the importance of identifying and quantifying the effects of contaminants as pharmaceuticals, disinfectants and surfactants in order to design and implement an ecotoxicological plan.
Assuntos
Apoptose/efeitos dos fármacos , Carpas/sangue , Misturas Complexas/toxicidade , Dano ao DNA , Hospitais , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/análise , Desinfetantes/análise , Ecotoxicologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/patologia , L-Lactato Desidrogenase/metabolismo , Dose Letal Mediana , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análiseRESUMO
Deficiencies of nutrients such as amino acids, vitamins, lipids, and trace elements during gestation and early infanthood have strong deleterious effects on the development of the limbic system; these effects may be irreversible, even when adequate supplementation is provided at later developmental stages. Recent advances in the neurochemistry of biometals are increasingly establishing the roles of the trace elements iron, copper, zinc, and selenium in a variety of cell functions and are providing insight into the repercussions of deficiencies and excesses of these elements on the development of the central nervous system, especially the limbic system. The limbic system comprises diverse areas with high metabolic demands and differential storage of iron, copper, zinc, and selenium. This review summarizes available evidence suggesting the involvement of these trace elements in pathological disorders of the limbic system.
Assuntos
Encefalopatias/etiologia , Sistema Límbico/efeitos dos fármacos , Sistema Límbico/crescimento & desenvolvimento , Oligoelementos/sangue , Oligoelementos/deficiência , Encefalopatias/sangue , Cobre/sangue , Cobre/deficiência , Cobre/fisiologia , Humanos , Ferro/sangue , Ferro/fisiologia , Deficiências de Ferro , Sistema Límbico/fisiologia , Fenômenos Fisiológicos da Nutrição/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição/fisiologia , Necessidades Nutricionais , Selênio/sangue , Selênio/deficiência , Selênio/fisiologia , Zinco/sangue , Zinco/deficiência , Zinco/fisiologiaRESUMO
Radiolabelled nanoparticles conjugated to peptides that target specific molecules can be used as agents for diagnosis. For example, technetium-99m-labelled gold nanoparticles conjugated to the cyclic [Arg-Gly-Asp-Phe-Lys(Cys)] (c[RGDfK(C)]) peptide are used for the molecular imaging of tumour-specific alpha(epsilon)beta(3) expression. Gold nanoparticles (AuNPs, 18-20 nm) are assumed to be safe at the concentrations used in diagnostic studies, and several studies of human toxicology and health implications have been discussed in a wide number of reports. However, no data are available on the potential ecotoxicity of radio-AuNPs conjugated to thiol-peptides after complete radionuclide decay. The aim of this study was to determine the ecotoxicological risk, measured by oxidative stress (OS) induction in Hyalella azteca, of a well-characterised multifunctional RGD-AuNP system (Tc-HYNIC-GGC-AuNP-c[RGDfK(C)]). TEM, UV-Vis, Raman, XPS, FT-IR and Far-IR spectroscopy techniques demonstrated that AuNPs were functionalised with the conjugated peptides. An acute toxicity test predicted an LC50 (72 h) of 1.83 cm2 per millilitre of medium. There were no statistically significant increases in OS and antioxidant defences after sub-acute exposure to a surface area concentration of 1/10 of the LC50. Tc-HYNIC-GGC-AuNP-c[RGDfK(C)] (20 nm) was demonstrated to be a chemically stable and nontoxic system in biological media after complete radionuclide decay because it does not promote the expression of OS and antioxidant defence enzymes, such as catalase, glutathione peroxidase and superoxide dismutase in Hyalella azteca.