RESUMO
The urgency for new materials in oncology is immediate. In this study we have developed the g-C3N4, a graphitic-like structure formed by periodically linked tris-s-triazine units. The g-C3N4has been synthesized by a simple and fast thermal process. XRD has shown the formation of the crystalline sheet with a compacted structure. The graphite-like structure and the functional groups have been shown by Raman and FTIR spectroscopy. TEM image and AFM revealed the porous composed of five or six C-N layers stacked. DRS and Photoluminescence analyses confirmed the structure with band gap of 2.87 eV and emission band at 448 nm in different wavelengths excitation conditions. The biological results showed inhibitory effect on cancer cell lines and non-toxic effect in normal cell lines. To the best of our knowledge, this is the first work demonstrating the cytotoxic effects of 2D g-C3N4in a cancer cell line, without any external or synergistic influence. The biodistribution/tissue accumulation showed that g-C3N4present a tendency to accumulation on the lung in the first 2 h, but after 24 h the profile of the biodistribution change and it is found mainly in the liver. Thus, 2D-g-C3N4showed great potential for the treatment of several cancer types.
Assuntos
Sobrevivência Celular , Grafite/síntese química , Grafite/metabolismo , Compostos de Nitrogênio/síntese química , Compostos de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Humanos , Distribuição TecidualRESUMO
The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A.millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil.However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.(AU)
Assuntos
Compostagem , Compostos de Nitrogênio/química , Compostos de Nitrogênio/metabolismo , Achillea/química , Achillea/metabolismo , Achillea/microbiologia , Anti-Infecciosos , Técnica Histológica de SombreamentoRESUMO
The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A.millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil.However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.
Assuntos
Achillea/metabolismo , Achillea/microbiologia , Achillea/química , Compostagem , Compostos de Nitrogênio/metabolismo , Compostos de Nitrogênio/química , Anti-Infecciosos , Técnica Histológica de SombreamentoRESUMO
Serratia marcescens is a γ-Proteobacterium and an opportunistic animal and insect pathogen. The bacterium exhibits a complex extracellular protein 'secretome' comprising numerous enzymes, toxins and effector molecules. One component of the secretome is the 'chitinolytic machinery', which is a set of at least four chitinases that allow the use of insoluble extracellular chitin as sole carbon source. Secretion of the chitinases across the outer membrane is governed by the chiWXYZ operon encoding a holin/endopeptidase pair. Expression of the chiWXYZ operon is co-ordinated with the chitinase genes and is also bimodal, as normally only 1% of the population expresses the chitinolytic machinery. In this study, the role of the ChiR protein in chitinase production has been explored. Using live cell imaging and flow cytometry, ChiR was shown to govern the co-ordinated regulation of chiWXYZ with both chiA and chiC. Moreover, overexpression of chiR alone was able to increase the proportion of the cell population expressing chitinase genes to >60â%. In addition, quantitative label-free proteomic analysis of cells overexpressing chiR established that ChiR regulates the entire chitinolytic machinery. The proteomic experiments also revealed a surprising link between the regulation of the chitinolytic machinery and the production of proteins involved in the metabolism of nitrogen compounds such as nitrate and nitrite. The research demonstrates for the first time that ChiR plays a critical role in controlling bimodal gene expression in S. marcescens, and provides new evidence of a clear link between chitin breakdown and nitrogen metabolism.
Assuntos
Proteínas de Bactérias/metabolismo , Quitinases/metabolismo , Serratia marcescens/fisiologia , Proteínas de Bactérias/genética , Quitinases/genética , Citometria de Fluxo , Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Microscopia de Fluorescência , Mutação , Compostos de Nitrogênio/metabolismo , Óperon , Proteômica , Serratia marcescens/genética , Serratia marcescens/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
This study aims to evaluate the effect of the Tifton 85 hay (Cynodon dactylon L. Pers) replacement by Orelha de Elefante Mexicana spineless cactus (Opuntia stricta [Haw.] Haw) on the nutrient intake and digestibility, growth performance, microbial protein synthesis, and efficiency of dietary nitrogen compound utilization in the diets of Girolando heifers. Twenty-four (3.5 months and 100 kg ± 3.5 kg) Girolando heifers (5/8 Holstein x Gyr) were used and arranged in a completely randomized design. Dry matter, organic matter, crude protein, and neutral detergent fiber decreased linearly as a function of the levels of Tifton hay (TH) replacement by Orelha de Elefante Mexicana spineless cactus (OEM). The non-fiber carbohydrate intake and coefficient of dry matter digestibility increased, while the neutral detergent fiber (NDF) digestibility decreased linearly with the OEM inclusion. After evaluating the growth performance by observing weight gain and morphometric measurements, there were no significant alterations. The urinary volume, nitrogen balance as well as the efficiency of nitrogen retention had increased, while the urinary and plasma urea concentrations had decreased linearly with the OEM inclusion. The results obtained in this study show that Orelha de Elefante Mexicana spineless cactus should replace Tifton hay in post-weaned heifer diets.
Assuntos
Bovinos/fisiologia , Cynodon/química , Digestão , Metabolismo Energético , Comportamento Alimentar , Compostos de Nitrogênio/metabolismo , Opuntia/química , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/microbiologia , Dieta/veterinária , Feminino , Microbioma Gastrointestinal/fisiologia , Distribuição Aleatória , Silagem/análiseRESUMO
Copper complexes with N3S donors mimic the CuM site of copper monooxygenases and react with O2 affording side-on cupric-superoxo complexes capable of H-abstraction from dihydroanthracene and THF. Spectroscopic and DFT data of the Cu-superoxos support a spin triplet ground state for the side-on complexes, as well as a hemilabile thioether.
Assuntos
Cobre/metabolismo , Oxigenases de Função Mista/metabolismo , Complexos Multienzimáticos/metabolismo , Compostos Organometálicos/metabolismo , Superóxidos/metabolismo , Benzimidazóis/química , Benzimidazóis/metabolismo , Domínio Catalítico , Cobre/química , Ligantes , Oxigenases de Função Mista/química , Estrutura Molecular , Complexos Multienzimáticos/química , Compostos de Nitrogênio/química , Compostos de Nitrogênio/metabolismo , Compostos Organometálicos/química , Compostos de Enxofre/química , Compostos de Enxofre/metabolismo , Superóxidos/químicaRESUMO
Large sulfur-oxidizing bacteria in the family Beggiatoaceae are important players in the global sulfur cycle. This group contains members of the well-known genera Beggiatoa, Thioploca, and Thiomargarita but also recently identified and relatively unknown candidate taxa, including "Candidatus Thiopilula" spp. and "Ca. Thiophysa" spp. We discovered a population of "Ca. Thiopilula" spp. colonizing cold seeps near Barbados at a â¼4.7-km water depth. The Barbados population consists of spherical cells that are morphologically similar to Thiomargarita spp., with elemental sulfur inclusions and a central vacuole, but have much smaller cell diameters (5 to 40 µm). Metatranscriptomic analysis revealed that when exposed to anoxic sulfidic conditions, Barbados "Ca. Thiopilula" organisms expressed genes for the oxidation of elemental sulfur and the reduction of nitrogenous compounds, consistent with their vacuolated morphology and intracellular sulfur storage capability. Metatranscriptomic analysis further revealed that anaerobic methane-oxidizing and sulfate-reducing organisms were active in the sediment, which likely provided reduced sulfur substrates for "Ca. Thiopilula" and other sulfur-oxidizing microorganisms in the community. The novel observations of "Ca. Thiopilula" and associated organisms reported here expand our knowledge of the globally distributed and ecologically successful Beggiatoaceae group and thus offer insight into the composition and ecology of deep cold seep microbial communities.
Assuntos
Temperatura Baixa , Perfilação da Expressão Gênica , Água do Mar/microbiologia , Thiotrichaceae/citologia , Thiotrichaceae/genética , Anaerobiose , Barbados , Análise por Conglomerados , Citoplasma/ultraestrutura , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Compostos de Nitrogênio/metabolismo , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Enxofre/metabolismo , Thiotrichaceae/isolamento & purificação , Vacúolos/ultraestruturaRESUMO
Avaliou-se a influência de métodos alternativos de destoxificação da torta de mamona sobre o balançode nitrogênio e avaliação ruminal em ovinos, alimentados com rações experimentais isoenergéticas eisoprotéicas. Foram utilizados vinte ovinos (dez machos inteiros e dez fêmeas) em cinco tratamentos(torta de mamona não tratada, tratada com calcário calcítico, ureia, fosfato monobicálcico e autoclavada)e quatro repetições. Para o balanço de nitrogênio utilizou-se delineamento em blocos ao acaso, sendo os blocos de acordo com o sexo do animal e para as variáveis pH e nitrogênio amoniacal (N-NH3) odelineamento utilizado foi em parcelas subdivididas, tendo nas parcelas as rações e nas subparcelas os tempos de coleta (0, 2, 5 e 8 horas pós-prandial). Os tratamentos não influenciaram o N consumido,urinário, ureia plasmática e N uréico no plasma (NUP). O N urinário foi superior na dieta contendo tortade mamona tratada com fosfato monobicálcico (FOS) quando comparada com aquela contendo torta de mamona tratada por autoclave (ACL). Já o balanço de nitrogênio (BN) foi maior na dieta ACL quando comparada à dieta FOS. Os valores de pH e N-NH3 mantiveram-se dentro da variação normal da espécie ovina, sendo pouco influenciados pelas rações. As rações com métodos de destoxificação da torta de mamona promoveram moderadas alterações no balanço de nitrogênio com destaque para a torta de mamona autoclavada e torta de mamona tratada com calcário calcítico. Os ovinos machos apresentaram balanço de nitrogênio superior às fêmeas.(AU)
Was evaluated the influence of alternative methods of detoxification of castor cake on nitrogen balanceand ruminal evaluation in sheep fed isocaloric and isonitrogenous experimental diets. Twenty sheep(ten males and ten females) were used in five treatments (castor cake untreated, treated with limestone,treated with urea, treated with phosphate monodicalcium and autoclaved) and four repetitions. Fornitrogen balance we used a randomized block design, with the blocks according to the sex and the variables pH and ammonia nitrogen (NH3-N) in the experimental design was split plot, with plots in the diets subplots and the collection times (0, 2, 5 and 8 hours postprandial).The treatments did notinfluence N intake, N urinary, urea and N-urea concentration in plasma. The Urinary N was higher in diet containing castor cake treated with phosphate monodicalcium (FOS) when compared with those containing castor cake treated by autoclave (ACL). Already the nitrogen balance (BN) was higher in diet ACL when compared to FOS diet. The pH and N-NH3 were within the normal range of sheep, being little affected by diet. Diets with methods of detoxification of castor cake promoted moderate changes in nitrogen balance with emphasis on the castor cake autoclaved and treated with limestone. The males sheep showed higher nitrogen balance than females.(AU)
Assuntos
Animais , Ovinos , Ricinus , Compostos de Nitrogênio/metabolismo , Ração AnimalRESUMO
Avaliou-se a influência de métodos alternativos de destoxificação da torta de mamona sobre o balançode nitrogênio e avaliação ruminal em ovinos, alimentados com rações experimentais isoenergéticas eisoprotéicas. Foram utilizados vinte ovinos (dez machos inteiros e dez fêmeas) em cinco tratamentos(torta de mamona não tratada, tratada com calcário calcítico, ureia, fosfato monobicálcico e autoclavada)e quatro repetições. Para o balanço de nitrogênio utilizou-se delineamento em blocos ao acaso, sendo os blocos de acordo com o sexo do animal e para as variáveis pH e nitrogênio amoniacal (N-NH3) odelineamento utilizado foi em parcelas subdivididas, tendo nas parcelas as rações e nas subparcelas os tempos de coleta (0, 2, 5 e 8 horas pós-prandial). Os tratamentos não influenciaram o N consumido,urinário, ureia plasmática e N uréico no plasma (NUP). O N urinário foi superior na dieta contendo tortade mamona tratada com fosfato monobicálcico (FOS) quando comparada com aquela contendo torta de mamona tratada por autoclave (ACL). Já o balanço de nitrogênio (BN) foi maior na dieta ACL quando comparada à dieta FOS. Os valores de pH e N-NH3 mantiveram-se dentro da variação normal da espécie ovina, sendo pouco influenciados pelas rações. As rações com métodos de destoxificação da torta de mamona promoveram moderadas alterações no balanço de nitrogênio com destaque para a torta de mamona autoclavada e torta de mamona tratada com calcário calcítico. Os ovinos machos apresentaram balanço de nitrogênio superior às fêmeas.
Was evaluated the influence of alternative methods of detoxification of castor cake on nitrogen balanceand ruminal evaluation in sheep fed isocaloric and isonitrogenous experimental diets. Twenty sheep(ten males and ten females) were used in five treatments (castor cake untreated, treated with limestone,treated with urea, treated with phosphate monodicalcium and autoclaved) and four repetitions. Fornitrogen balance we used a randomized block design, with the blocks according to the sex and the variables pH and ammonia nitrogen (NH3-N) in the experimental design was split plot, with plots in the diets subplots and the collection times (0, 2, 5 and 8 hours postprandial).The treatments did notinfluence N intake, N urinary, urea and N-urea concentration in plasma. The Urinary N was higher in diet containing castor cake treated with phosphate monodicalcium (FOS) when compared with those containing castor cake treated by autoclave (ACL). Already the nitrogen balance (BN) was higher in diet ACL when compared to FOS diet. The pH and N-NH3 were within the normal range of sheep, being little affected by diet. Diets with methods of detoxification of castor cake promoted moderate changes in nitrogen balance with emphasis on the castor cake autoclaved and treated with limestone. The males sheep showed higher nitrogen balance than females.
Assuntos
Animais , Compostos de Nitrogênio/metabolismo , Ovinos , Ricinus , Ração AnimalRESUMO
This study was carried out aiming to evaluate the effects of yeast or monensin supplementation on dry matter intake, nutrients digestibility, ruminal volatile fatty acids profile, ruminal pH and ammonia concentration, microbial protein synthesis, and the balance of nitrogen compounds of cattle fed high concentrate diet (80 % dry matter (DM) basis) with two different levels of starch. Eight crossbred beef steers fitted with rumen cannula were assigned to two simultaneous 4 × 4 Latin squares arranged in a 4 × 2 factorial design. Two different starch levels (23 and 38 % of DM) were assigned to each Latin square, independently. Within each Latin square, four treatments were randomly assigned to the experimental animals (control; monensin; 1-g yeast [1 g/100 kg body weight (BW)/day] treatment; and 2.5-g yeast [2.5 g/100 kg BW/day] treatment). Feed additives did not influence ruminal pH (P > 0.05). Total ruminal volatile fatty acids (VFA) concentration was greater (P<0.05) in the diet with the lowest starch level. Similarly, monensin and 1-g yeast treatments resulted in greater (P<0.05) VFA concentration in the rumen. Monensin inclusion in the diet with the highest starch level led to a decrease (P<0.05) in lactate concentration in the rumen. However, acetate levels were increased (P<0.05) by the inclusion of 1 g of yeast in the diet with lowest starch level. Ruminal concentrations of propionate and butyrate, and ammonia-N were not influenced (P>0.05) by none of the additives evaluated. However, propionate concentration was greater (P<0.05) in the low-starch diets. Low-starch diets resulted in lower ruminal ammonia-N concentration and greater neutral detergent fiber digestibility (P<0.05). The excretion of urinary nitrogenous compounds, purine derivatives, synthesis of microbial protein, microbial efficiency, and balance of nitrogenous compounds were not affected by treatments evaluated (P>0.05). Monensin or yeast inclusion in high concentrate beef cattle diets in tropical regions as in Brazil is not justified by do not alter nutrient digestibility, nitrogen balance, and main ruminal parameters.
Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Bovinos/fisiologia , Comportamento Alimentar , Monensin/metabolismo , Fermento Seco/metabolismo , Ração Animal/análise , Animais , Brasil , Dieta/veterinária , Suplementos Nutricionais/análise , Digestão/efeitos dos fármacos , Fermentação , Concentração de Íons de Hidrogênio , Masculino , Monensin/administração & dosagem , Compostos de Nitrogênio/metabolismo , Rúmen/fisiologia , Amido/metabolismo , Fermento Seco/administração & dosagemRESUMO
As respostas das plantas forrageiras à nutrição nitrogenada depende não somente da quantidade do nutriente disponível mas também da sua forma química, como íons NH4+ ou NO3-. ambas as formas podem ser absorvidas e metabolizadas, com conseguencias diferenciadas para a produtividade vegetal. Algumas espécies tem preferência ecológica por uma ou outra forma, enquanto a maioria produz mais usando as formas em combinação. Para verificar o comportamento metabólico e produtivo do capim Tifton 85 em reação a formas e doses de N mineral foram conduzidos dois experimentos, nas instalações do Instituto de Agronomia da Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica-RJ. O experimento I foi conduzido em câmara de crescimento tipo fitotron sob condições controladas, utilizando-se cultivo hidroônico e teve duração de 35 dias, contados a partir de um corte de uniformização (DAC). oS TRATAMENTOS CONSISTIRAM DE DUAS FORMAS DE N:NH4 + (sulfato de amônio) e NO3- (nitrato de Ca, Mg e K) combinadas com quatro doses de aplicação: 0,5; 2; 5 e 10 mM, respecitivamente, quatro datas de amostragem, aos 14, 21, 28 e 35 DAC. O experimento Ii foi conduzido em casa de vegetação, utilizando-se como substrato de crescimento, terra proveniente do horizonte superficial de um Planossolo Háplico, de ocorrência na área da UFRRJ e sob cultivo de Tifton 85. Utilizou-se uma única fonte de N, representativa das duas formas (nitrato de amônio), aplicado em quatro doses (de 0,80, 160 e 240 mg N kg solo -1) e avaliado em quatro épocas (aos 14, 21, 28, e 35 DAC). Em ambos os experimentos os tratamentos foram repetidos quatro vezes. Foram feitas as seguintes determinações: massa fresca e seca de raízes, arte aérea e total, teores de N-total, N-solúveis em etanol 80% todos determinados em lâminas foliares, bainhas, colmos e raízes; assim com oteores de clorofila foliar (extraídas com N,N dimetilformamida) e da determinada com clorofilômetro. Em relação a formas de N inorgânico isoladas, o capim Tifton 85 respondeu á nutricção amoniacal, em ralação à nítrica. com maior produção de massa fresca e massa seca total, maior fração de alocação da biomassa total às raízes, maior teor de clorofila total e maiores teores de açúcares solúveis e aminoácidos em folhas e raízes. Além disso, apresentou bixos teores de N-NH4+ em todos compartimentos das plantas, mesmo em altas doses de N. Sob o ponto de vista nutricional, as concentrações encontradas para N-NO3-, mesmo nas doses de N mais elevadas, não oferecem risco de intoxicação de animais ruminantes. Quanto a utilização de forma mista (NO3NH4), o comportamento metabólico das plantas sob este tratamento maximizou aprodução de biomassa e reproduziu traços similares aos verificados sob nutrição puramente amoniacal, incluindo maior produção de clorofila, e alocação preferencial de açucares solúveis e aminoácidos em raízes e colmos. A nutrição mista não aumentou a eficiência assimilatória em relação à utilização exclusiva de nutrição amociacal ou nítrica. Foi concluído que uma nutrição 100% amonical, ou 50% NH4+ + NO3- , foram superiores, em termos de eficiência assimilatória de N, do que uma nutição 100% nítrica, fenômeno este não documentado
Assuntos
Animais , Biomassa , Compostos de Nitrogênio/metabolismo , Desoxigenação NitrogenadaRESUMO
Wastewater sludge can be used to fertilize crops, especially after vermicomposting (composting with earthworms to reduce pathogens). How wastewater sludge or vermicompost affects bean (Phaseolus vulgaris L.) growth is still largely unknown. In this study the effect of different forms of N fertilizer on common bean plant characteristics and yield were investigated in a Typic Fragiudepts (sandy loam) soil under greenhouse conditions. Beans were fertilized with wastewater sludge, or wastewater sludge vermicompost, or urea, or grown in unamended soil, while plant characteristics and yield were monitored (the unamended soil had no fertilization). Yields of common bean plants cultivated in unamended soil or soil amended with urea were lower than those cultivated in wastewater sludge-amended soil. Application of vermicompost further improved plant development and increased yield compared with beans cultivated in wastewater amended soil. It was found that application of organic waste products improved growth and yield of bean plants compared to those amended with inorganic fertilizer.
Assuntos
Fertilizantes/análise , Compostos de Nitrogênio/metabolismo , Phaseolus/crescimento & desenvolvimento , Phaseolus/metabolismo , Esgotos/química , Solo/análiseRESUMO
This article proposes a simple "in-situ" pulse respirometric method for the estimation of four important kinetic and stoichiometric parameters. The method is validated in a suspended biomass nitrifying reactor for the determination of (i) maximum oxygen uptake rate (OUR(ex)max), (ii) oxidation yield (f(E)), (iii) biomass growth yield (f(S)), and (iv) affinity constant (K(S)). OUR(ex)max and f(E) were directly obtained from respirograms. In the presented case study, a minimum substrate pulse of 10 mgNH(4) (+)-N L(-1) was necessary to determine OUR(ex)max which was 61.15 +/- 4.09 mgO(2) L(-1) h(-1) (5 repetitions). A linear correlation (r(2) = 0.93) obtained between OUR(ex)max and the biomass concentration in the reactor suggests that biomass concentration can be estimated from respirometric experiments. The substrate oxidation yield, f(E), was determined along 60 days of continuous operation with an average error of 5.6%. The biomass growth yield was indirectly estimated from the substrate oxidation yield f(E). The average obtained value (0.10 +/- 0.04 mgCOD mg(-1)COD) was in accordance with the f(S) estimation by the traditional COD mass balance method under steady-state conditions (0.09 +/- 0.01). The affinity constant K(S) was indirectly estimated after fitting the ascending part of the respirogram to a theoretical model. An average value of 0.48 +/- 0.08 mgNH(4) (+)-N L(-1) was obtained, which is in the range of affinity constants reported in the literature for the nitrification process (0.16-2 mgNH(4) (+)-N L(-1)).
Assuntos
Algoritmos , Fenômenos Fisiológicos Bacterianos , Modelos Biológicos , Compostos de Nitrogênio/metabolismo , Consumo de Oxigênio/fisiologia , Oxigênio/metabolismo , Proliferação de Células , Simulação por Computador , CinéticaRESUMO
Effect of aeration rate on the removal of organic matter and nitrogen and on the formation of NH3, N2O and N2 was studied for an extensive biofiltration system packed with an organic media, which was used to treat pig manure. The results show high removal of BOD5 and TSS (99 and > or = 98%), independently of the four aeration rate tested (3.4-34 m3/m2 x h). Aeration rate > or = 4.4 m/h resulted in high ammonia stripping during start-up (> or = 1.0 kg NH3-N/m3 of swine manure treated), while using 3.4 m/h only 0.3 kg NH3-N/m3 were stripped. Complete nitrification was achieved after day 100 of operation, except in the biofilter with the lowest aeration rate. Simultaneous denitrification established in all the biofilters. Applying an aeration rate of 9.4 m/h up to 1.2 kg nitrogen was removed in the form of N2 for each m3 of swine manure treated. Contrary to the expectations, N2 formation and release increased with the aeration rate. This particular behaviour seems to be related to the punctual accumulation of water layers inside the biofilters, caused by the air force flowing in the opposite direction to the water flux. N2O production was quite similar in all biofilters (between 0.25-0.36 kg N2O-N/m3 of swine manure treated).
Assuntos
Ar , Reatores Biológicos , Esterco , Compostos de Nitrogênio/metabolismo , Eliminação de Resíduos/métodos , Animais , Filtração , Compostos de Nitrogênio/química , Oxigênio/análise , Suínos , Poluentes Químicos da Água/análiseRESUMO
The production of a battery of arabinoxylan-degrading enzymes by the fungus Penicillium brasilianum grown on brewer's spent grain (BSG) under solid-state fermentation was investigated. Initial moisture content, initial pH, temperature, and nitrogen source content were optimized to achieve maximum production of feruloyl esterase, xylanase, and alpha-L: -arabinofuranosidase. Under the optimum growth conditions (80% moisture, pH 6, 26.5 degrees C, and 5 g/l nitrogen source), the maximum level of feruloyl esterase (1,542 mU/g BSG) was found after 196 h, whereas xylanase (709 U/g BSG) and ArabF activity (3,567 mU/g BSG) were maximal after 108 h and 96 h, respectively. Based on substrate utilization data, the feruloyl esterases produced by P. brasilianum was anticipated to subclass B. A crude enzyme (CE) preparation from P. brasilianum culture grown on BSG was tested for the release of hydroxycinnamic acids and pentoses from BSG. The P. brasilianum CE produced in this work contains a balance of cell wall-modifying enzymes capable of degrading arabinoxylan of BSG by more than 40%.
Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Glicosídeo Hidrolases/metabolismo , Penicillium/enzimologia , Xilanos/metabolismo , Hidrolases de Éster Carboxílico/biossíntese , Hidrolases de Éster Carboxílico/isolamento & purificação , Ácidos Cumáricos/metabolismo , Grão Comestível/metabolismo , Endo-1,4-beta-Xilanases/biossíntese , Endo-1,4-beta-Xilanases/isolamento & purificação , Fermentação , Liofilização , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Glicosídeo Hidrolases/biossíntese , Glicosídeo Hidrolases/isolamento & purificação , Umidade , Concentração de Íons de Hidrogênio , Compostos de Nitrogênio/metabolismo , Penicillium/crescimento & desenvolvimento , Pentoses/metabolismo , Especificidade por Substrato , Temperatura , Fatores de TempoRESUMO
BACKGROUND: Potassium dichromate (K2Cr2O7)-induced nephrotoxicity is associated with oxidative and nitrosative stress. In this study we investigated the relation between the time course of the oxidative and nitrosative stress with kidney damage and alterations in the following antioxidant enzymes: Cu, Zn superoxide dismutase (Cu, Zn-SOD), Mn-SOD, glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT). METHODS: Nephrotoxicity was induced in rats by a single injection of K2Cr2O7. Groups of animals were sacrificed on days 1,2,3,4,6,8,10, and 12. Nephrotoxicity was evaluated by histological studies and by measuring creatinine clearance, serum creatinine, blood urea nitrogen (BUN), and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and total protein. Oxidative and nitrosative stress were measured by immunohistochemical localization of protein carbonyls and 3-nitrotyrosine, respectively. Cu, Zn-SOD, Mn-SOD, and CAT were studied by immunohistochemical localization. The activity of total SOD, CAT, GPx, and GR was also measured as well as serum and kidney content of chromium and urinary excretion of NO2 -/NO3-. Data were compared by two-way analysis of variance followed by a post hoc test. RESULTS: Serum and kidney chromium content increased reaching the highest value on day 1. Nephrotoxicity was made evident by the decrease in creatinine clearance (days 1-4) and by the increase in serum creatinine (days 1-4), BUN (days 1-6), urinary excretion of NAG (days 1-4), and total protein (day 1-6) and by the structural damage to the proximal tubules (days 1-6). Oxidative and nitrosative stress were clearly evident on days 1-8. Urinary excretion of NO2-/NO3- decreased on days 2-6. Mn-SOD and Cu, Zn-SOD, estimated by immunohistochemistry, and total SOD activity remained unchanged. Activity of GPx decreased on days 3-12 and those of GR and CAT on days 2-10. Similar findings were observed by immunohistochemistry of CAT. CONCLUSION: These data show the association between oxidative and nitrosative stress with functional and structural renal damage induced by K2Cr2O7. Renal antioxidant enzymes were regulated differentially and were not closely associated with oxidative or nitrosative stress or with kidney damage. In addition, the decrease in the urinary excretion of NO2-/NO3- was associated with the renal nitrosative stress suggesting that nitric oxide was derived to the formation of reactive nitrogen species involved in protein nitration.
Assuntos
Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Compostos de Nitrogênio/metabolismo , Estresse Oxidativo , Oxirredutases/metabolismo , Dicromato de Potássio , Acetilglucosaminidase/urina , Animais , Catalase/metabolismo , Cromo/sangue , Cromo/metabolismo , Creatina/sangue , Creatina/urina , Glutationa Peroxidase/metabolismo , Imuno-Histoquímica , Rim/efeitos dos fármacos , Rim/metabolismo , Nefropatias/patologia , Túbulos Renais Proximais/patologia , Masculino , Nitratos/urina , Nitritos/urina , Dicromato de Potássio/intoxicação , Proteinúria/fisiopatologia , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismoRESUMO
Irradiation of sewage sludge reduces pathogens and can hydrolyze or destroy organic molecules. The effect of irradiation of sewage sludge on C and N dynamics in arable soil and possible interference with toxic organic compounds was investigated in soil microcosms using a clay soil. The soil was treated with phenanthrene and anthracene, with and without irradiated and non-irradiated sewage sludge amendment. All the treated soils were incubated for 182 days at 25 degrees C. The CO2 production and dynamics of inorganic N (NH4+, NO2- and NO3-) were monitored. Addition of sewage sludge (0.023 g g(-1) soil), anthracene or phenanthrene (10.0 microg g(-1) soil dissolved in methanol), and methanol (10 mg g(-1) soil) to soil had a significant effect on CO2 production compared to the control. However, there were no significant differences between soil treated with irradiated and non-irradiated sewage sludge. Irradiated sewage sludge increased the C and N mineralization of anthracene amended soils to a greater extend than in phenanthrene amended soils. Nitrification was inhibited for 28 days in soil treated with either methanol, anthracene and phenanthrene. Application of sewage sludge reduced such toxicity effects after 28 days incubation.
Assuntos
Silicatos de Alumínio/efeitos da radiação , Antracenos/química , Dióxido de Carbono/metabolismo , Compostos de Nitrogênio/metabolismo , Fenantrenos/química , Esgotos/química , Microbiologia do Solo , Silicatos de Alumínio/química , Antracenos/metabolismo , Carbono/química , Carbono/metabolismo , Argila , Enterobacteriaceae/metabolismo , Enterobacteriaceae/efeitos da radiação , Metanol/metabolismo , Minerais/química , Minerais/metabolismo , Nitrogênio/química , Nitrogênio/metabolismo , Compostos de Nitrogênio/química , Fenantrenos/metabolismo , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Esgotos/microbiologia , Solo/análiseRESUMO
Tannery sludge contains valuable nutrients and could be used as a fertilizer to pioneering vegetation in heavily eroded soils of the semi-arid highlands of central Mexico. Soil collected under and outside the canopy of mesquite (Prosopis laeviginata), huizache (Acacia tortuoso) and catclaw (Mimosa biuncifera), and cultivated with maize (Zea mays) and beans (Phaesolus vulgaris) was amended with 1.5 g tannery sludge kg-1 soil or 210 kg dry sludge ha-1 or left unamended. Amended and unamended soils were incubated aerobically for 70 days at 22 +/- 2 degrees C and CO2 production, available P, and inorganic N concentrations were monitored. The CO2 production rate, total C and P, available P, biomass C and P were larger under the canopy of the vegetation than outside of the canopy. The soils were depleted of N as more than 50 mg N kg-1 soil could not be accounted for in the first days of the incubation. Nitrification showed a lag, which lasted 28 days, and concentration of available P remained constant or increased slightly. Application of tannery sludge to soil increased CO2 production with 6.5 mg CO2 kg-1 soil d-1 and inorganic N with 30 mg N kg-1 soil after 70 days, but available P did not increase. Application of tannery sludge increased C and N mineralization and could thus provide valuable nutrients to a pioneer vegetation. Although no inhibitory effects on the biological functioning of the soil were found, further investigation into possible long-term environmental effects are necessary.
Assuntos
Carbono/análise , Nitrogênio/análise , Fósforo/análise , Esgotos/química , Solo/análise , Curtume , Biomassa , Carbono/metabolismo , Dióxido de Carbono/metabolismo , Ecossistema , Fabaceae/metabolismo , Humanos , México , Nitrogênio/metabolismo , Compostos de Nitrogênio/metabolismo , Fósforo/metabolismo , Plantas Medicinais , Microbiologia do Solo , Zea mays/metabolismoRESUMO
The enzymatic study and transport of N in the xylem sap was carried out with a view to observing the influence of different nitrate levels and growth stages of the plant in chemically treated mutants of Lupinus albus. Several stresses induce a reduction in plant growth, resulting in the accumulation of free amino acids, amides or ureides, not only in the shoot, but also in the roots and nodules. Although enzyme activity is decisive in avoiding products that inhibit nitrogenase by ammonium, little is known about the mechanism by wich the xylem carries these products. However, this process may be the key to the function of avoiding the accumulation of amino acids in the cells of infected nodules. The behaviour of the enzymes nitrate reductase (NR), phosphoenolpyruvate carboxylase (PEPC), glutamine synthetase (GS) and nitrogen compounds derived from fixation, such as N-Ó-amino, N-ureides and N-amide in mutant genotypes were observed. The NR enzyme was highly influenced by the application of nitrate showing much higher values than those in the non-application of nitrate, independently of genotype, being that the NR, the best evaluation period was in the tenth week. The L-62 genotype characterized with nitrate-resistance, clearly showed that the enzyme PEPC is inhibited by presence of nitrate. The L-135 genotype (nor fix) showed GS activity extremely low, thus demonstrating that GS is an enzyme highly correlated with fixation. With regard to the best growth stage for GS, Lupinus albus should be evaluated in the seventh week.
Assuntos
Fosfoenolpiruvato Carboxilase/metabolismo , Fabaceae/enzimologia , Nitrato Redutases/metabolismo , Nitratos/análise , Compostos de Nitrogênio/metabolismo , Glutamato-Amônia Ligase/metabolismo , Nitrogênio/metabolismo , Fabaceae/crescimento & desenvolvimento , Fabaceae/genéticaRESUMO
The effect of fortification of concentrated whey with 0.5% inorganic nitrogen viz. NH4Cl, (NH4)2SO4, NaNO3 and urea, organic nitrogen viz. tryptone, tryptose, peptone and yeast extract and 0.1% metal ions viz. K2HPO4, MgSO4 and FeSO4, on growth stimulation of Kluyveromyces marxianus subsp. marxianus NRRL Y-665, NRRL Y-1195, NRRL Y-2415 and Kluyveromyces marxianus subsp. lactis NRRL Y-1193 were studied. Supplementation with 0.5% (NH4)2SO4, peptone, yeast extract or 0.1% K2HPO4 individually increased the biomass production by 8-20%, 17-25%, 13-14% and 14-17%, respectively. Addition of 0.5% each of (NH4)2SO4, peptone, yeast extract and 0.1% K2HPO4 together is recommended to increase the biomass production by 81-98% for commercial production of single cell protein.