RESUMO
Mining has led to severe environmental pollution in countries with exhaustive mining production and inadequate industrial waste regulation. Microorganisms in contaminated sites, like mine tailings, have adapted to high concentrations of heavy metals, developing the capacity of reducing or removing them from these environments. Therefore, it is essential to thoroughly characterize bacteria present in these sites to find different ways of bioremediation. In this regard, in this study, an enrichment and isolation procedure were performed to isolate bacteria with lower nutritional requirements and high tolerance to Cu(II) and Fe(II) from two Sonoran River basin mining tails. Two Staphylococcus species and a Microbacterium ginsengisoli strain were isolated and identified from the San Felipe de Jesús mining tail. Also, three strains were isolated from the Nacozari de García mining tail: Burkholderia cenocepacia, Sphingomonas sp. and Staphylococcus warneri. Significant microbiological differences were found between the two sites. All these species exhibited tolerance up to 300 mg/L for Cu (II)-Fe (II) solutions, indicating their capacity to grow in these conditions. Moreover, a consortium of isolated bacteria was immobilized in two different biocomposites and the biocomposite with larger pore size achieved greater bacterial immobilization showcasing the potential of these bacteria in biotechnological applications.
Assuntos
Metais Pesados , Poluentes do Solo , Metais Pesados/análise , Resíduos Industriais/análise , Mineração , Biodegradação Ambiental , Bactérias , Poluentes do Solo/análiseRESUMO
Due to the high concentration of pollutants, swine wastewater needs to be treated prior to disposal. The combination of anaerobic and aerobic technologies in one hybrid system allows to obtain higher removal efficiencies compared to those achieved via conventional biological treatment, and the performance of a hybrid system depends on the microbial community in the bioreactor. Here, we evaluated the community assembly of an anaerobic-aerobic hybrid reactor for swine wastewater treatment. Sequencing of partial 16S rRNA coding genes was performed using Illumina from DNA and retrotranscribed RNA templates (cDNA) extracted from samples from both sections of the hybrid system and from a UASB bioreactor fed with the same swine wastewater influent. Proteobacteria and Firmicutes were the dominant phyla and play a key role in anaerobic fermentation, followed by Methanosaeta and Methanobacterium. Several differences were found in the relative abundances of some genera between the DNA and cDNA samples, indicating an increase in the diversity of the metabolically active community, highlighting Chlorobaculum, Cladimonas, Turicibacter and Clostridium senso stricto. Nitrifying bacteria were more abundant in the hybrid bioreactor. Beta diversity analysis revealed that the microbial community structure significantly differed among the samples (p < 0.05) and between both anaerobic treatments. The main predicted metabolic pathways were the biosynthesis of amino acids and the formation of antibiotics. Also, the metabolism of C5-branched dibasic acid, Vit B5 and CoA, exhibited an important relationship with the main nitrogen-removing microorganisms. The anaerobic-aerobic hybrid bioreactor showed a higher ammonia removal rate compared to the conventional UASB system. However, further research and adjustments are needed to completely remove nitrogen from wastewater.
Assuntos
Chlorobi , Microbiota , Purificação da Água , Animais , Suínos , Águas Residuárias , Esgotos/química , Eliminação de Resíduos Líquidos , Anaerobiose , Chlorobi/genética , RNA Ribossômico 16S/genética , DNA Complementar , Reatores Biológicos/microbiologiaRESUMO
We present the synthesis and characterization of organic Salphen compounds containing bromine substituents at the para/ortho-para positions, in their symmetric and non-symmetric versions, and describe the X-ray structure and full characterization for the new unsymmetrical varieties. We report for the first time antiproliferative activity in metal-free brominated Salphen compounds, by evaluations in four human cancer cell lines, cervix (HeLa), prostate (PC-3), lung (A549) and colon (LSâ 180) and one non-cancerous counterpart (ARPE-19). We assessed inâ vitro cell viability against controls using the MTT assay ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide)) and determined the concentration required for 50 % growth inhibition (IC50 ), together with their selectivity vs. non-cancerous cells. We found promising results against prostate (9.6â µM) and colon (13.5â µM) adenocarcinoma cells. We also found a tradeoff between selectivity (up to 3-fold vs. ARPE-19) and inhibition, depending upon the symmetry and bromine-substitution of the molecules, showing up to 20-fold higher selectivity vs. doxorubicin controls.
Assuntos
Antineoplásicos , Bromo , Masculino , Feminino , Humanos , Bromo/farmacologia , Células HeLa , Fenilenodiaminas/farmacologia , Antineoplásicos/química , Proliferação de Células , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Relação Estrutura-Atividade , Estrutura MolecularRESUMO
In recent years, overexploited industrialization and urbanization activities have led to significant amounts of heavy metals released into the environment. Metal ion contamination of water, especially with toxic metals such as nickel(II) [Ni(II)], which is extensively applied in the electroplating industry, has been a serious problem. The aim of the present study was to evaluate the Ni(II) removal from real industrial wastewater using a 2 L, lab-scale, up-flow, anaerobic, zeolite-packed bioreactor inoculated with a heterotrophic consortium as the bioadsorbent. High-throughput sequencing of 16S rRNA genes revealed significant shifts in their bacterial diversity and structural composition along the bioreactor treatment location, where the bacterial genus was dominated by Kosmotogae followed by Firmicutes as Ruminococcus and Clostridium. However, Fervidobacterium and the Geobacter genus were absent at the end of the bioreactor treatment, suggesting that they play a key role in the beginning of Ni(II) removal anaerobic treatment. The physico-chemical results revealed that the Ni(II) removal rate was 99% for 250-500 ppm metal tested, with an efficient alkalinity rate and high production of biogas, which confirmed that anaerobic digestion of microorganisms was successfully performed through the process. Finally, this anaerobic bioreactor configuration offers an accessible and ecofriendly high-rate metal removal strategy from mining and electroplating effluents.
Assuntos
Águas Residuárias , Zeolitas , Anaerobiose , Reatores Biológicos , Níquel , RNA Ribossômico 16S/genéticaRESUMO
This work aimed to evaluate the link between the occurrence/abundance of Vibrio populations and bacterial composition in shrimp's intestine (Litopenaeus vannamei) during post-larval ontogenetic development and in its culture water, and the correlation of these with environmental parameters. The total and metabolically active populations of Vibrio in the digestive tract of shrimp during its post-larval development were analysed using quantitative PCR (qPCR) and reverse transcription qPCR targeting the 16S rRNA gene sequence. A lab-scale shrimp bioassay was performed for 80 days in a recirculating aquarium under strictly controlled conditions. The results indicate that the Vibrio population from shrimp's gut is associated with its developmental stage and the environment. Multivariate analyses revealed that the presence of Vibrio spp. drove the studied system, but their metabolically active performance was related to earlier developmental stages in an aqueous environment. Also, the samples taken from water of culture units to compare the influence of the aquatic environment on the intestinal microbial community during shrimp's ontogenetic development showed significant differences. Finally, our results revealed that Vibrio is an important member of shrimp's gut microbiota; however, its metabolic activity seems to be highly regulated, possibly by the host and by the rest of the microbiota.
Assuntos
Bioensaio , Microbioma Gastrointestinal , Penaeidae/microbiologia , Vibrio/metabolismo , Animais , Biometria , Trato Gastrointestinal/microbiologia , Concentração de Íons de Hidrogênio , Imunidade Inata , Análise Multivariada , Reação em Cadeia da Polimerase , Análise de Componente Principal , RNA Ribossômico 16S/metabolismo , TemperaturaRESUMO
Trichloroethylene (TCE) is a carcinogenic compound that is commonly present in groundwater and has been detected in drinking water sources for Mexican towns in the Mexico-US border area. Nitrifying bacteria, such as Nitrosomonas europaea, have been shown to be capable of degrading halogenated compounds, including TCE, but it is difficult to obtain high cell concentrations of these bacteria. The aim of the present study was to generate biomass of a nitrifying bacterial consortium from the sludge of an urban wastewater treatment plant (WWTP) and evaluate its capacity to biodegrade TCE in two different natural lab-scaled packed bed bioreactors. The consortium was isolated by a novel method using a continuous stirred-tank bioreactor inoculated with activated sludge from the Domos WWTP located in Cd. Obregón, Sonora, Mexico. The bioreactor was fed with specific media to cultivate ammonia-oxidizing bacteria at a dilution rate near the maximum specific growth rate reported for Nitrosomonas europaea. Optical density and suspended solids measurements were performed to determine the culture biomass production, and the presence of inorganic nitrogen species was determined by spectrophotometry. The presence of nitrifying ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) was confirmed by PCR amplification, and biofilm formation was observed by scanning electron microscopy. Batch-scale experiments confirmed the biodegradative activity of the isolated consortium, which was subsequently fixed in an inorganic carrier as zeolite and a synthetic carrier such as polyurethane to both be used as lab-scale packed-bed bioreactors, with up to 58.63% and 62.7% of TCE biodegradation achieved, respectively, demonstrating a possible alternative for TCE bioremediation in environmental and engineering systems.
Assuntos
Tricloroetileno , Amônia , Bactérias , Biodegradação Ambiental , Reatores Biológicos , México , Nitritos , Oxirredução , EsgotosRESUMO
The increased global demand for food production has motivated agroindustries to increase their own levels of production. Scientific efforts have contributed to improving these production systems, aiding to solve problems and establishing novel conceptual views and sustainable alternatives to cope with the increasing demand. Although microorganisms are key players in biological systems and may drive certain desired responses toward food production, little is known about the microbial communities that constitute the microbiomes associated with agricultural and veterinary activities. Understanding the diversity, structure and in situ interactions of microbes, together with how these interactions occur within microbial communities and with respect to their environments (including hosts), constitutes a major challenge with an enormous relevance for agriculture and biotechnology. The emergence of high-throughput sequencing technologies, together with novel and more accessible bioinformatics tools, has allowed researchers to learn more about the functional potential and functional activity of these microbial communities. These tools constitute a relevant approach for understanding the metabolic processes that can occur or are currently occurring in a given system and for implementing novel strategies focused on solving production problems or improving sustainability. Several 'omics' sciences and their applications in agriculture are discussed in this review, and the usage of functional metagenomics is proposed to achieve substantial advances for food agroindustries and veterinary sciences.
Assuntos
Microbiologia de Alimentos , Metagenômica/métodos , Plantas/microbiologia , Animais , Archaea/classificação , Archaea/genética , Bactérias/classificação , Bactérias/genética , Abastecimento de Alimentos , Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , RNA Ribossômico 16S/genéticaRESUMO
The structure of the biofouling layers formed on a pilot-scale membrane-coupled upflow anaerobic sludge blanket bioreactor (UASB) used to treat urban wastewater was analyzed by scanning electron microscopy and electron-dispersive X-ray microanalysis. For comparison, control samples of the membranes were fed either UASB effluent or raw wastewater in a laboratory-scale experiment. Microbial diversity in the fouling materials was analyzed by temperature gradient gel electrophoresis (TGGE) combined with sequence analysis of partial 16S rRNA. Significant differences in structure of the Bacteria communities were observed amongst the different fouling layers analyzed in the UASB membranes, particularly following a chemical cleaning step (NaClO), while the Archaea communities retained more similarity in all samples. The main Bacteria populations identified were evolutively close to Firmicutes (42.3%) and Alphaproteobacteria (30.8%), while Archaea were mostly affiliated to the Methanosarcinales and Methanospirillaceae. Sphingomonadaceae-related bacteria and methanogenic Archaea were persistently found as components of biofouling, regardless of chemical cleaning.