Analysis of time-related metabolic fluctuations induced by ethionine in the rat

The time-course of metabolic events following response to a model hepatotoxin ethionine (800 mg/kg) was investigated over a 7 day period in rats using high-resolution (1)H NMR spectroscopic analysis of urine and multivariate statistics. Complementary information was obtained by multivariate analysis of (1)H MAS NMR spectra of intact liver and by conventional histopathology and clinical chemistry of blood plasma. (1)H MAS NMR spectra of liver showed toxin-induced lipidosis 24 h postdose consistent with the steatosis observed by histopathology, while hypertaurinuria was suggestive of liver injury. Early biochemical changes in urine included elevation of guanidinoacetate, suggesting impaired methylation reactions. Urinary increases in 5-oxoproline and glycine suggested disruption of the gamma-glutamyl cycle. Signs of ATP depletion together with impairment of the energy metabolism were given from the decreased levels in tricarboxylic acid cycle intermediates, the appearance of ketone bodies in urine, the depletion of hepatic glucose and glycogen, and also hypoglycemia. The observed increase in nicotinuric acid in urine could be an indication of an increase in NAD catabolism, a possible consequence of ATP depletion. Effects on the gut microbiota were suggested by the observed urinary reductions in the microbial metabolites 3-/4-hydroxyphenyl propionic acid, dimethylamine, and tryptamine. At later stages of toxicity, there was evidence of kidney damage, as indicated by the tubular damage observed by histopathology, supported by increased urinary excretion of lactic acid, amino acids, and glucose. These studies have given new insights into mechanisms of ethionine-induced toxicity and show the value of multisystem level data integration in the understanding of experimental models of toxicity or disease.

Gut microbial catabolism of grape seed flavan-3-ols by human faecal microbiota. Targetted analysis of precursor compounds, intermediate metabolites and end-products.

In vitro batch culture fermentations were conducted with grape seed polyphenols and human faecal microbiota, in order to monitor both changes in precursor flavan-3-ols and the formation of microbial-derived metabolites. By the application of UPLC-DAD-ESI-TQ MS, monomers, and dimeric and trimeric procyanidins were shown to be degraded during the first 10 h of fermentation, with notable inter-individual differences being observed between fermentations. This period (10 h) also coincided with the maximum formation of intermediate metabolites, such as 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone and 4-hydroxy-5-(3′,4′-dihydroxyphenyl)-valeric acid, and of several phenolic acids, including 3-(3,4-dihydroxyphenyl)-propionic acid, 3,4-dihydroxyphenylacetic acid, 4-hydroxymandelic acid, and gallic acid (5–10 h maximum formation). Later phases of the incubations (10–48 h) were characterised by the appearance of mono- and non-hydroxylated forms of previous metabolites by dehydroxylation reactions. Of particular interest was the detection of γ-valerolactone, which was seen for the first time as a metabolite from the microbial catabolism of flavan-3-ols. Changes registered during fermentation were finally summarised by a principal component analysis (PCA). Results revealed that 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone was a key metabolite in explaining inter-individual differences and delineating the rate and extent of the microbial catabolism of flavan-3-ols, which could finally affect absorption and bioactivity of these compounds.

Synthesis of biodegradable polyhydroxyalcanoate copolymer from a renewable source by alternate feeding

Polyhydroxyalcanoates copolymers with 3-hydroxybutirate (3HB) and 3-hydroxyvalerate (3HV) co-monomers, P3(HB-co-x%HV), were produced in fed-batch culture by Ralstonia eutropha DSM428 using fructose as a single carbon source in the first step and adding propionic acid in the second step by alternating feeding. Polymer yield was 0.18 g/L with a content of 24 mol% of the 3HV fraction determined by H-1 NMR. NMR measurements indicated that the polymer obtained is isotactic. The copolymer attained 35% of crystallinity according to X-ray diffraction measurements, and two (020) planes were observed. Thermal behavior presented melting temperature at 154 degrees C and the crystallization temperature was 65 degrees C. A glass transition temperature was observed at -10 degrees C. Average molecular weight measured by GPC was 4.9 x 10(5) Dalton. Isothermal radial growth rates of spherulites of P3(HB-co-24%HV) were studied. All experimental facts and the analysis of the sequence distribution of diads and triads of 3HB and 3HV units led to the conclusion that it is not a completely statistical random copolymer once it contains different types of segments. POLYM.

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV) with a broad range of 3HV content at high yields by Burkholderia sacchari IPT 189

The biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from sucrose and propionic acid by Burkholderia sacchari IPT 189 was studied using a two-stage bioreactor process. In the first stage, this bacterium was cultivated in a balanced culture medium until sucrose exhaustion. In the second stage, a solution containing sucrose and propionic acid as carbon source was fed to the bioreactor at various sucrose/propionic acid (s/p) ratios at a constant specific flow rate. Copolymers with 3HV content ranging from 40 down to 6.5 (mol%) were obtained with 3HV yield from propionic acid (Y-3HV/prop) increasing from 1.10 to 1.34 g g(-1). Copolymer productivity of 1 g l(-1) h(-1) was obtained with polymer biomass content rising up to 60% by increasing a specific flow rate at a constant s/p ratio. Increasing values of 3HV content were obtained by varying the s/p ratios. A simulation of production costs considering Y-3HV/prop obtained in the present work indicated that a reduction of up to 73% can be reached, approximating US$ 1.00 per kg which is closer to the value to produce P3HB from sucrose (US$ 0.75 per kg).

Screening of bacteria to produce polyhydroxyalkanoates from xylose

Although xylose is a major constituent of lignocellulosic feedstock and the second most abundant sugar in nature, only 22% of 3,152 screened bacterial isolates showed significant growth in xylose in 24 h. Of those 684, only 24% accumulated polyhydroxyalkanoates after 72 h. A mangrove isolate, identified as Bacillus sp. MA3.3, yielded the best results in literature thus far for Gram-positive strains in experiments with glucose and xylose as the sole carbon source. When glucose or xylose were supplied, poly-3-hydroxybutyrate (PHB) contents of cell dry weight were, respectively, 62 and 64%, PHB yield 0.25 and 0.24 g g(-1) and PHB productivity (P(PHB)) 0.10 and 0.06 g l(-1) h(-1). This 40% P(PHB) difference may be related to the theoretical ATP production per 3-hydroxybutyrate (3HB) monomer calculated as 3 mol mol(-1) for xylose, less than half of the ATP/3HB produced from glucose (7 mol mol(-1)). In PHB production using sugar mixtures, all parameters were strongly reduced due to carbon catabolite repression. PHB production using Gram-positive strains is particularly interesting for medical applications because these bacteria do not produce lipopolysaccharide endotoxins which can induce immunogenic reactions. Moreover, the combination of inexpensive substrates and products of more value may lead to the economical sustainability of industrial PHB production.

Avaliação de efeitos biológicos de antiinflamatórios derivados do ácido propiônico através de modelos experimentais em nível molecular e celular

Derivatives of propionic acid NSAIDs are irreversible inhibitors of cyclooxygenase enzyme widely used. The aim of this study was to evaluate, through different experimental models, biological effects of derivatives of propionic acid (fenoprofen, naproxen, ibuprofen and ketoprofen) in cellular and molecular level. The labeling of blood constituents with technetium-99m (99mTc) and morphological analysis of erythrocytes of blood of rats, as well as growth, survival of cultures of Escherichia coli (E. coli) and the assessment of bacterial plasmid electrophoretic profiles were models used for experimental evaluation of possible biological effects of antiinflammatory drugs. The results show that, in general, anti-inflammatory drugs evaluated were not able to alter the labeling of blood constituents with 99mTc, the morphology of red blood cells from blood of rats, as well as the growth of cultures of E. coli and the electrophoretic profile of plasmid DNA. However, naproxen appears to cytotoxic effect on bacterial cultures, plasmids and genotoxic effects in reducing the action of stannous chloride in cultures of E. coli. The use of experimental fast performance and low cost was important for assessment of biological effects, contributing to a better understanding of the properties of propionic acid derivatives studied. anti-inflammatory, blood constituents, technetium-99m, stannous chloride, Escherichia coli; DNA

Efeito de sementes oleaginosas inteiras e óleo de soja sobre a digestibilidade in vitro e os padrões ruminais de bezerros holandeses

Este trabalho foi realizado para comparar os efeitos da adição de sementes inteiras de soja e algodão e de óleo de soja sobre os padrões ruminais e a digestibilidade in vitro, em bezerros Holandeses fistulados. Dois bezerros fistulados no rúmen foram alimentados com dieta basal com 2,5% de extrato etéreo (EE), o qual foi comparado com dietas com 5,0% de EE, em que as sementes de soja e algodão inteira ou o óleo de soja foram fontes de EE adicional. A adição de sementes de soja e de algodão resultou em decréscimo na digestibilidade in vitro da matéria seca e da fibra em detergente neutro (FDN), porém não houve alterações na digestibilidade in vitro da fibra em detergente ácido (FDA) em relação à dieta controle. A adição de semente algodão provocou decréscimo na digestibilidade in vitro da proteína bruta em comparação à dieta controle. A concentração de ácido propiônico nas dietas com adição de óleo de soja foi 16% mais elevada que a proporcionada pelas demais dietas. O uso de óleo de soja pareceu ser a mais adequada em relação à digestibilidade da matéria seca, FDA e FDN e à manutenção de pH, quando comparado a outros tipos de adição lipídica, porém menos eficiente que a semente de soja em relação à digestibilidade in vitro da proteína bruta. O número de protozoários apresentou grande variação entre dietas, mas nenhum efeito com adição de óleo foi observado. A maior concentração de N-NH3 ruminal foi obtida na dieta com óleo de soja, quando comparada às outras dietas.

Degradabilidade in situ e parâmetros ruminais em bovinos alimentados com dietas balanceadas para diferentes ganhos de peso e potenciais de fermentação microbiana

Um experimento foi realizado com o objetivo de avaliar os parâmetros ruminais, a produção de ácidos graxos voláteis e a degradabilidade in situ em tourinhos Santa Gertrudes canulados no rúmen alimentados com dietas compostas de feno de capim-marandu e concentrado. Empregou-se o delineamento em quadrado latino 4 ´ 4, no qual os tratamentos foram compostos dos concentrados, ajustados para ganho de peso corporal (GPC) diário de 0,5 e 1 kg/animal e potencial de fermentação microbiana (y) de 9,5 e 11 g de proteína bruta microbiana/MJ energia metabolizável fermentável. Não foram encontradas interações significativas nem diferenças entre as dietas para pH, concentração molar dos ácidos acético e butírico e proporção molar dos ácidos acético, propiônico e butírico e relação acético:propiônico. Os teores de amônia diferiram entre os potenciais de fermentação microbiana, 14,67 e 20,83 mg/100 mL para baixo e alto, respectivamente, e a concentração molar de ácido propiônico foi diferente entre os potenciais de ganho de peso, 7,62 e 8,94 mM, respectivamente, para baixo e alto ganho de peso. Não foram detectadas diferenças entre dietas para as degradabilidades das frações do feno de capim-marandu e da soja em grão. Houve diferença no parâmetro b e na degradabilidade efetiva a 5%/hora da proteína bruta para os potencias de GPC do milho em grão moído. Para o farelo de soja, ocorreu interação significativa entre os potencias de GPC e de fermentação microbiana para alguns dos parâmetros da MS e PB, o mesmo observado para o farelo de algodão. As diferenças encontradas não justificaram o balanceamento dos concentrados para os diferentes potenciais de produção avaliados.

Prevention of Salmonella infection by contact using intestinal flora of adult birds and/or a mixture of organic acids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fermentation and aerobic stability of high-moisture corn silages inoculated with different levels of Lactobacillus buchneri

Fermentation and aerobic stability were evaluated in high-moisture corn (HMC) silage inoculated with different levels of Lactobacillus buchneri. The HMC composed of 654 g/kg dry matter (DM) was ensiled in quadruplicate laboratory silos (7 L) per treatment. L. buchneri 40788 was applied at 5 × 10(4); 1 × 10(5); 5 × 10(5); and 1 × 10(6) cfu/g to the ground corn. Silages with no additive were used as controls. After 140 d of ensiling, the silages were subjected to an aerobic stability evaluation for 12 days in which the chemical parameters, microbiological parameters and silage temperature were measured to determine the aerobic deterioration. The lactic acid, acetic acid and propionic acid concentrations did not differ between silages. The fermentation parameters of HMC were not affected by L. buchneri. The HMC containing L. buchneri had a low number of yeast and mould colonies and a more stable pH until in the eighth measurement, which improved the aerobic stability without affecting gas loss. Doses of L. buchneri greater than or equal to 5 × 10(5) cfu/g applied to the HMC were the most efficient in control of aerobic deterioration.

Fermentation and aerobic stability of corn silage inoculated with Lactobacillus buchneri

The characteristics of fermentation and aerobic stability were evaluated in corn silage inoculated with different doses of Lactobacillus buchneri. The whole corn plant (300 g/kg DM) was ensiled in quadruplicate laboratory silos (7L). L. buchneri 40788 was applied at 5×10(4), 1×10(5), 5×10(5) and 1×10(6) cfu/g of fresh forage. Silages with no additive were used as controls. After 130 d of ensiling, the silages were subjected to an aerobic stability evaluation for 12 days, in which chemical and microbiological parameters as well as the temperature of the silage were measured to determine the aerobic deterioration. The addition of L. buchneri resulted in increased acetic acid concentrations. The number of yeast colonies was low in all treated silages. The pH, lactic and propionic acid concentrations did not differ between silages. Under aerobic conditions, all the treated silages showed a low number of yeasts and a great aerobic stability. Therefore, L. buchneri is effective against yeasts and improves the aerobic stability of corn silage in laboratory silos. However, doses equal or superior to 1×10(5) cfu/g of fresh forage were more efficient in the control of aerobic spoilage.

Desempenho produtivo e atividade microbiana cecal de coelhos alimentados com dietas contendo diferentes níveis de amido

Com o objetivo de avaliar a influência do amido dietético sobre o rendimento produtivo e a atividade microbiana cecal de coelhos em crescimento, quatro dietas experimentais foram elaboradas de forma a conter níveis crescentes de amido (23, 28, 33 e 38% de amido total na base da MS), os quais foram fornecidos a 32 coelhos da raça Nova Zelândia Branco, distribuídos em gaiolas de engorda individuais, seguindo um delineamento em blocos casualizados. Houve efeito linear decrescente para consumo e conversão alimentar, em que valores de 108,67 g/d e 3,216, respectivamente, foram obtidos para os animais alimentados com 38% de amido dietético. No entanto, o ganho de peso e o rendimento de carcaça não foram influenciados pelos tratamentos. Por outro lado, os valores de pH, as concentrações totais e as proporções molares dos ácidos graxos voláteis não foram influenciados pelos tratamentos, porém, para o ácido propiônico, houve efeito linear decrescente, sendo a maior proporção molar (12,06%) verificada no conteúdo cecal de coelhos alimentados com 23% de amido dietético. O milho-grão apresentou maior influência sobre a atividade microbiana cecal que o amido de milho purificado, porém, sem alterar o desempenho e rendimento de carcaça.

Ação Isolada ou Combinada de Ácidos Orgânicos e Promotor de Crescimento em Rações de Frangos de Corte

O experimento teve como objetivo verificar a ação da apramicina (10 ppm) e dos ácidos fórmico + propiônico (0,0; 0,1 e 0,2%) no desempenho de frangos de corte sexados. A mistura dos ácidos orgânicos foi de 1:1. O delineamento foi inteiramente casualizado, em esquema fatorial 2 x 3 x 2 (apramicina x ácidos orgânicos x sexos), com 4 repetições de 45 aves por parcela, totalizando 2.160 pintos Cobb de 1 dia. As aves receberam ração à vontade. Na fase inicial, a adição da apramicina (10 ppm) e 0,1% dos ácidos orgânicos, isoladamente, melhorou o ganho de peso das aves. A adição conjunta dos produtos não promoveu ganho acumulado. Na presença da apramicina, a adição dos ácidos orgânicos piorou a conversão alimentar. Nas fases final e total, os dados de desempenho não apresentaram diferenças significativas. O rendimento de carcaça foi prejudicado com a adição conjunta da apramicina e 0,1% dos ácidos orgânicos.

Synthesis and characterization of a novel series of meso (nitrophenyl) and meso (carboxyphenyl) substituted porphyrins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de métodos de coleta de fluido ruminal em bovinos sobre alguns parâmetros ruminais e microbiológicos

Estudou-se o efeito de três métodos de coleta (manual, bomba a vácuo e sonda nasoesofageana) sobre os teores de ácidos graxos voláteis totais (AGVt), nitrogênio amoniacal e número de protozoários no fluido ruminal de bovino. Utilizou-se o delineamento inteiramente casualizado, com três tratamentos e cinco repetições. Os resultados revelaram que o método da sonda nasoesofageana proporcionou valores menores dos ácidos propiônico, butírico, AGVt e de nitrogênio amoniacal no fluido ruminal. O número total de protozoários não foi afetado pelos métodos de coleta de conteúdo ruminal. O método de coleta manual e por meio de bomba a vácuo mostraram-se eficientes para os parâmetros estudados.