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Efeito de diferentes tratamentos para o controle da contaminação superficial com salmonella typhimurium em carcaças suínas / Effect of diverse treatment for control of salmonella Typhimurium surface contamination in pork carcassGouveia, Fábio Carvalho de 12 December 2008 (has links)
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Previous issue date: 2008-12-12 / The contamination in pork meat and other pork products by Salmonella sp. is a heath public problem, and is a risk factor for the consumer. Pork without symptom is the principal way to carrier Salmonella sp. into slaughterhouses. To control the superficial contamination of pork carcass by Salmonella Typhimurium, the use of organic acid solution and pressure of steam, in isolated or associated treatments, were verified in muscle and skin of the carcasses. Four treatments were applied: immersion in physiologic solution; immersion in acid solution at 1000 ppm (witch is made by organic acids; citric acid is the principal ingredient); sprinkling of steam at 140ºC at 4 bar of pressure; and sprinkling of steam after immersion in acid solution. Superficial areas of 100cm2 were availed at skin and muscle of the carcasses. The Most Probable Number (MPN) of Salmonella sp. was obtained in each sample by sterile swabs. The frequencies of reduction of the MPN were availed by Fisher exactly test. At skin, the better frequency of reduction was observed by use of steam after immersion in acid solution, achieving reduction in 100% of the samples. At muscle, reduction of MPN was observed in 100% of the samples treated by acid solution or sprinkling of steam after immersion in acid solution / As contaminações por Salmonella sp. em carnes e produtos cárneos suínos são um problema de saúde pública e trazem riscos ao consumidor. Suínos portadores assintomáticos são os principais veículos de contaminação de plantas industriais frigoríficas. Com o objetivo de controlar as contaminações superficiais de carcaças suínas por Salmonella Typhimurium foi proposto o uso de solução de ácidos orgânicos e aplicação de vapor sob pressão, em tratamentos isolados ou em associação. Pernis suínos refrigerados foram utilizados como modelos experimentais, e foram artificialmente contaminados por imersão em solução salina fisiológica contendo 103 UFC/mL de Salmonella Typhimurium fagotipo DT177. Áreas de 100cm2 da superfície dos pernis suínos foram amostradas, e estimados os NMP de Salmonella sp. antes e após cada tratamento, tanto na musculatura como na pele. As freqüências de redução dos NMP foram avaliadas pelo teste exato de Fisher. Observou-se que o tratamento em associação de solução ácida (solução de ácidos orgânicos contendo o ácido cítrico como principal constituinte) a 1000ppm e vapor a 140ºC sob pressão de 4bar apresentou melhor resultado em comparação aos mesmos tratamentos isolados, e ao controle com solução fisiológica. Nas avaliações na pele, as freqüências de redução variaram de 50% (tratamento com solução ácida) a 100% (associação de tratamentos com solução ácida mais vapor sob pressão). Já na musculatura, as freqüências variaram de 44% (tratamento com solução fisiológica e tratamento com aplicação de vapor) a 100% (tratamento com solução ácida e tratamento com solução ácida seguido por tratamento pela aplicação de vapor)
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Protease e butirato de sódio nas dietas pré-inicial e inicial de suínos / Protease and sodium butyrate diets in pre-initial and initial swinesSilva, Juliana Luis e 12 December 2013 (has links)
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Previous issue date: 2013-12-12 / It was aimed to evaluate the zootechnical performance, digestible parameters,
diarrhea frequency, blood parameters, organs weight, ph content of the
digestive tract and intestinal histomorphology of pigs in the nursery stage fed
with feed containing protease and sodium butyrate. In the performance test 80
commercial crossbreed castrated male piglets, 21 days old and initial average
weight of 5.11 ± 0.4645 kg, allotted in an experimental lineation randomized
block, with four treatments, five repetitions and four animals by repetition. The
experiment performance was divided into three phases, being the pre-initial
from 5.5 to 9 kg, initial 1 from 9.3 to 15 kg, and initial 2 from 15 to30 kg.
Treatments consisted of basal diet, containing 200ppm inclusion of protease,
basal diet with 0.3% addition of sodium butyrate and basal diet with protease
(200ppm) and sodium butyrate (0.3 %). It was determined the daily weight gain,
daily feed intake, nourish conversion, diarrhea frequency; hematological and
biochemical profile; pH of the contents of the stomach, duodenum, jejunum,
ileum, colon, cecum and rectum; weighing of organs and histomorphometry
parameters was determined in the segment of duodenum, jejunum and ileum .
The digestibility experiments with pigs from nursery stage has been divided into
two stages, with stage I to animals with an average weight of 11.770 ± 0.730 kg
and stage II in which animals weighed on average 1.280 kg ± 23,070. In each
digestibility experiment, 16 commercial crossbred castrated male piglets were
used, the experimental lineation was randomized blocks with four treatments
and four repetitions. Treatments consisted of basal diet, basal diet with 200ppp
inclusion of protease, basal diet with 0.3% addition of sodium butyrate and
basal diet with protease (200ppm) and sodium butyrate (0.3 %). It was
determined the digestible energy and coefficient of digestibility and
metabolizabilety dry material, gross energy, crude protein and mineral material.
Protease and sodium butyrate did not influence the parameters of daily weight
gain, daily feed intake and feed conversion. The protease decreases the
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incidence of diarrhea in the initial phase 2. Sodium butyrate and protease
isolated and its association improved metabolisability coefficient of the protein,
the protease increased mineral absorption. Sodium butyrate decreased the
number of blood platelets. There were no differences in pH values of the
intestinal contents of the stomach, duodenum, jejunum, ileum, colon, cecum,
and rectum. Sodium butyrate showed lower relative weight value of the small
intestine and pancreas, protease decreased the weight of the small intestine
and the liver, the association of protease and sodium butyrate decreased by the
pancreatic weigh. Sodium butyrate increased the base of the duodenal villi
protease and villus height decreased in the ileum. The production and
enzymatic activity of the protease was not limiting in post weaning performance.
The better utilization of nutrients caused by protease and sodium butyrate
decreased the functional load of the organs of the digestive tract, reflecting
lower weight of the small intestine, liver and pancreas. Sodium butyrate
contributes to the development of intestinal mucosa of piglets. / Objetivou-se avaliar o desempenho zootécnico, parâmetros digestíveis,
frequência de diarreia, parâmetros sanguíneos, peso de órgãos, ph do
conteúdo do trato digestivo e histomorfologia intestinal de suínos em fase de
creche alimentados com ração contendo protease e butirato de sódio. No
ensaio de desempenho foram utilizados 80 leitões híbridos comerciais, machos
castrados, com 21 dias de idade e peso médio inicial de 5,11 ± 0,4645 kg,
distribuídos em delineamento experimental de blocos ao acaso, com quatro
tratamentos, cinco repetições e quatro animais por repetição. O experimento de
desempenho foi dividido em três fases, sendo fase pré-inicial de 5,5 a 9 kg,
inicial 1 de 9,3 a 15 kg e inicial 2 de 15 a 30 kg. Os tratamentos consistiram de
ração basal, ração basal com 200ppm de inclusão de protease, ração basal
com 0,3% de inclusão de butirato de sódio e ração basal com protease
(200ppm) e butirato de sódio (0,3%). Foi determinado o ganho de peso diário,
consumo diário de ração, conversão alimentar; frequência de diarreia; perfil
hematológico e bioquímico; pH dos conteúdos do estômago, duodeno, jejuno,
íleo, cólon, ceco e reto; pesagem de órgãos e parâmetros histomorfométricos
nos segmentos de duodeno, jejuno e íleo. O experimento de digestibilidade
com suínos em fase de creche foi dividido em duas fases, sendo fase I com
animais de peso médio de 11,770 ± 0,730 kg e fase II em que os animais
pesavam em média 23,070 ± 1,280 kg. Em cada experimento de
digestibilidade, foram utilizados 16 leitões híbridos comerciais, machos
castrados, o delineamento experimental utilizado foi o de blocos ao acaso, com
quatro tratamentos e quatro repetições. Os tratamentos consistiram de ração
basal, ração basal com 200ppp de inclusão de protease, ração basal com 0,3%
de inclusão de butirato de sódio e ração basal com protease (200ppm) e
butirato de sódio (0,3%). Foi determinado a digestibilidade da energia e os
coeficientes de digestibilidade e de metabolizabilidade da matéria seca, energia
bruta, proteína bruta e matéria mineral. Protease e butirato de sódio não
influenciaram os parâmetros de ganho de peso diário, consumo diário de ração
e conversão alimentar. A protease diminui a incidência de diarreia na fase
inicial 2. Butirato de sódio e protease isolados e sua associação melhoraram o
coeficiente de metabolizabilidade da proteína; a protease aumentou a absorção
de minerais. Butirato de sódio diminuiu o número de plaquetas no sangue. Não
houve diferenças nos valores de pH dos conteúdos intestinais do estômago,
duodeno, jejuno, íleo, cólon, ceco, reto. Butirato de sódio apresentou menores
valores de peso relativo do intestino delgado e do pâncreas, protease diminuiu
o peso do intestino delgado e do fígado, a associação de protease e butirato de
sódio diminuiu o peso do pâncreas. Butirato de sódio aumentou a base da
vilosidade do duodeno e a protease diminuiu a altura da vilosidade no íleo. A
produção e atividade enzimática da protease não foi limitar no desempenho
pós desmame. O melhor aproveitamento de nutrientes causado pela protease e
butirato de sódio, diminiui a carga funcional dos órgãos do trato digestivo,
refletindo em menores pesos de intestino delgado, fígado e pâncreas. Butirato
de sódio contribui para o desenvolvimento da mucosa intestinal de leitões.
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Efeito dos ácidos lático e butírico, isolados e associados, sobre o desempenho, imunidade humoral e morfometria intestinal em frangos de corte / Effect of latic and butiric acids, isolated and associated, on performance, humoral immunity and intestinal morfometric in broilersPaulo Cesar Riquelme Salazar 21 July 2006 (has links)
Durante os últimos anos a avicultura nacional tem sofrido constantes desafios, tendo como objetivo ampliar o mercado consumidor do frango de corte ao redor do mundo. Entretanto, cada mercado apresenta exigências diferentes, como no caso do mercado europeu que estabelece a exclusão dos antibióticos como promotores de crescimento na alimentação dos frangos de corte. Visando esta problemática, realizou-se este estudo, com o objetivo de analisar os resultados da utilização dos ácidos lático e butírico, isolados e associados, como aditivos em dietas de frangos de corte, em relação ao promotor de crescimento usualmente utilizado nas dietas dos mesmos. Foram avaliados: o desempenho, a imunidade humoral e a morfometria intestinal das aves. Utilizaram-se 1400 pintainhos machos da linhagem comercial Ross, divididos em cinco tratamentos (controle - sem aditivo -; ácido butírico; ácido lático; ácido butírico + ácido lático e avilamicina - antibiótico, promotor de crescimento tradicionalmente utilizado na produção de frangos de corte). Os resultados de desempenho indicaram que a interação dos ácidos foi significativa na fase inicial, entretanto não ocorreu um efeito aditivo dos ácidos, sendo o uso do ácido butírico isoladamente mais recomendável durante essa fase. Já na fase de crescimento, a interação foi significativa com um efeito aditivo, recomendando seu uso nas rações de crescimento. De acordo com os títulos médios de anticorpos obtidos no estudo, a interação foi significativa aos 35 dias de idade e mostrou um efeito sinérgico, sendo a combinação dos ácidos em questão um potente modulador da imunidade humoral. Os resultados obtidos nas análises de morfometria intestinal não foram conclusivos. Em termos gerais, requerem-se mais estudos quanto ao uso dos ácidos orgânicos como promotores de crescimento. / During the last years, the national poultry keeping has suffered constant challenges, having as objective to diversify the consuming market of the broiler to around of the world. However, each market presents different requirements, as in the case of the European market that establishes the exclusion of antibiotics as promotional of growth in the feeding of the broilers. Aiming at this problematic one, this study was become fullfilled, with the objective to analyze the results of the association of the butyric and lactic acids as additives in the ration of broilers, in comparison to the results gotten for the usually used promoters of growth in the diets of broilers. They had been evaluated: the animal performance, humoral immunology and intestinal morfometric of the birds. 1400 male chickens of the commercial ancestry Ross had been used, dividing them in five groups with different treatments to that if it relates to the additive use. Being a group it has controlled absent of additive, a group with butyric acid, a group with lactic acid, the fourth group with the association of butyric and lactic acids, and the fifth group with avilamicina (antibiotic) as promotional of traditionally used growth in the production of broilers. The performance results had indicated that the interaction of acid ones was significant in the initial phase, mean while did not occur an additive effect of acid ones, being the use of the butyric acid separately more recommendable during this phase. Already in the growth phase, the interaction was significant with an additive effect, recommending its use in the rations of growth. In accordance with the average headings of antibodies gotten in the study, the interaction was significant in the third sampling and showed a synergic effect of acid ones, being the combination of acids in question a powerful modulator of the humoral immunity. Meanwhile, the results gotten in the analyses of intestinal morfometric had not been conclusive. In general terms, one requires more organic acid studies that confirm the use of as the promotional ones of growth.
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The effect of filler metal on the corrosion resistance of stainless steel weldments in a hot organic acid environmentOrsmond, Charles Petrus Marais 30 August 2010 (has links)
Selective corrosion of type 316L austenitic stainless steel welds during the production of organic acids resulted in losses in production due to unscheduled downtimes to perform repairs. Estimated corrosion rates of type 316L filler material welds were an order of magnitude higher than that of the base material. Alternative higher alloyed commercial filler materials were evaluated under actual production conditions. The evaluated filler materials were types 316L, 317L, 309L, 309MoL, 2205, 2507, 625, 825 and 904L. The effect of nitrogen on the corrosion properties of type 309L filler material was evaluated by manipulating the nitrogen concentration of the shielding gas during MIG welding. These changes in nitrogen concentration did not influence the corrosion resistance of the type 309L filler material. No correlation could be established between the corrosion rates, analysed chemical composition of the product and operating temperature during production. In almost all the cases where the chemical composition of the filler material was comparable with that of the base material the corrosion rates of the filler materials were higher than that base material. It might be expected that the ferrite phase with higher molybdenum and chromium should be more corrosion resistant while the austenite should be less resistant. This was, however, not the case with the corrosion of type 309L filler material. It would thus appear that in this case nickel enrichment of the austenite phase had a larger influence on the corrosion resistance of the austenite phase than the chromium and molybdenum had on the corrosion resistance of the ferrite phase. It appears that nickel and molybdenum had the largest contribution to the corrosion resistance of stainless steels welds under these operating conditions. It is, however, believed that a certain minimum concentration of chromium is also required to provide corrosion resistance to these alloys in hot organic acid environments. In contrast with the fact that a substantial alloying content is required to improve corrosion resistance of the filler material, the small difference in composition between ferrite and austenite phases, due to micro segregation, appeared to affect the corrosion resistance on micro scale. This is illustrated by the micrographs, which show corrosion to etch out the dendrite structure. Since the morphology of the austenite and ferrite phases is so similar, it could not always be conclusively established which one of the two phases corroded selectively. Analyses performed on the austenite and ferrite phases did not indicate a concentration difference within the phases itself. However, there were significant differences in the concentration of elements between the phases, with the austenite stabilising elements reporting to the austenite phase and the ferrite stabilizing elements reporting to the ferrite phase, in line with thermodynamic predictions. In the case of the filler materials following the austenite mode of solidification, no significant concentration differences were detected within the matrix. Although all highly alloyed high nickel alloyed filler materials (types 904L, 825 and 625) corroded at a lower rate than the type 316L base material, type 625 filler material was the filler material of choice due to the lack of any pitting of the weld. Pitting was detected in both the 825 and 904L filler materials. Galvanic corrosion was not noted at any of the weld/HAZ interfaces and in no case did the type 316L parent metal adjacent to the weld corrode preferentially to the material further away from the weld. Copyright / Dissertation (MEng)--University of Pretoria, 2010. / Materials Science and Metallurgical Engineering / unrestricted
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Difluoroboronate Urea-Induced Acid Amplification for Insertion ChemistryCouch, Erica Dawn 07 October 2014 (has links)
No description available.
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Elektroforetické stanovení organických kyselin v průmyslových roztocích / Electrophoretic determination of organic acids in industrial solutionsTaraba, Lukáš January 2014 (has links)
This work deals with the development and optimization of conditions of pretreatment of two industrial surface finishing baths containing chromium(III) ions and oxalic, maleic, acetic or citric acid and their electrophoretic analysis. Some model mixtures containing known amounts of components of industrial solutions have been made for simulation of complex matrices of the real samples. Prior to analysis a sample pre-treatment consisting of different dilution and addition of fluoride, hydroxide or EDTA anions as suitable agent releasing acid out of the stable chromium complex were studied. Determination of organic anions was accomplished by indirect UV detection at 350 nm with a reference at 230 nm. A commercially available background electrolyte, pH 5.7, was used for separation of analytes. The most appropriate pre-treatment to release acids have been achieved by precipitation of chromium(III) hydroxide. The method of standard additions was used for the quantification. The concentrations of oxalate and citrate in the real samples were calculated as 96,50 % (S.D. = 0,71 %) and 97,53 % (S.D. = 0,79 %), respectively, of declared amount. Satisfactory repeatabilities were obtained for both analytes with R.S.D. values (n = 5) for migration times lower than 0,51 %, R.S.D. for peak areas of oxalic acid were...
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Přenos nabitých a nenabitých částic přes modelové biologické membrány / Transport of charged and neutral particles across the model biomembranesParisová, Martina January 2012 (has links)
This work was focused on the preparation of model stabilized phospholipid membranes formed on porous polycarbonate carrier. 1,2-dipalmitoyl-sn-glycero-3-phosphocholin was used for their formation in hydrophilic pores of polycarbonate carrier. For characterization of the formation of phospholipid layers, their changes and a study of transport processes, electrochemical impedance spectroscopy and voltammetry were used. Transport of cadmium and copper ions was studied in the presence and in the absence of ionophore calcimycin which was incorporated into the formed of phospholipid membrane. Because these ions are often bound in complexes with various substances, such as low molecular weight organic acids (LMWOAs), this work was also focused on the transport of copper and cadmium ions across the model phospholipid membranes in the presence of malic acid, citric acid and oxalic acid at different pH. Besides the use of ionophore, some pilot experiments were performed to realize the transfer of copper ions using two peptides, nisin and transportan 10. Formation of phospholipid membranes and the transport processes were characterized by two proposed electric equivalent circuits which correspond to the covered and to the uncovered polycarbobate carrier. Keywords: Phospholipids, Membranes, Ionophore, Peptid....
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Avaliação de aditivos químicos e microbianos como inibidores da síntese de etanol em silagens de cana-de-açúcar (Saccharum officinarum L.) / Chemical and microbial additives for the inhibition of ethanol synthesis in sugarcane silageSousa, Daniel de Paula 12 December 2006 (has links)
O trabalho teve por objetivo avaliar fatores associados à ensilagem da cana-deaçúcar, com destaque para a aplicação de aditivos químicos e microbianos sobre a dinâmica fermentativa, composição bromatológica, atividade da álcool desidrogenase e desenvolvimento e diversidade da micloflora em silagens de cana-de-açúcar. No ensaio conduzido durante 110 dias o delineamento experimental adotado foi o inteiramente ao acaso, com 4 tratamentos, 2 repetições, e seis épocas de abertura (1, 3, 7, 15, 35, 110 dias). Os tratamentos foram: uréia 1% MV e os inoculantes microbianos Lactobacillus buchneri (3,65x105 ufc/g da MV) e a combinação de bactérias Pedioccocus pentosassus e Lactobacillus buchneri (1x106 ufc/g MV). As maiores variações na composição bromatológica e perdas de MS, das silagens controle ocorreram dos 7 aos 15 dias, estabilizando após esse período. As regressões ajustadas para perdas de MS e carboidratos solúveis foram bem similares e de forma contrária ao acúmulo de FDN. As perdas por gases alcançaram valores de 28,27%, de carboidratos solúveis em apenas 2,98% e FDN em torno de 67,77% da MS. Os aumentos nos teores de etanol e perda na digestibilidade nas silagens controle se extenderam até o 35º dia, com valores máximos de etanol de 12,23%. Foi possível relacionar etanol com a digestibilidade mostrando que cada 1% de aumento nos teores de etanol, 2 unidades de digestibilidade foram perdidas. Os aditivos uréia e o aditivo Lactobacillus buchneri mais Pediococcus foram eficazes em diminuir a produção de etanol (2,75 e 1,30 vs 8,27% no tratamento controle), em diminuir perdas de MS em 47 e 60%, e de carboidratos soluveis em 22 e 56% em relação à silagem controle, respectivamente. As silagens aditivadas com uréia obtiveram maiores valores de pH e maiores valores de ácido lático em relação às silagen controle. As silagens aditivadas com L. buchneri apenas foram as de maiores produções de etanol, acima da silagem controle (11.53 vs 8.27%), além de grandes perdas de matéria seca e baixa digestibilidade pelo acúmulo de FDN, comparáveis às silagens controle. A diferença entre aditivos na composição químico-bromatológica e perdas ocorreu após 7 dias de fermentação. Os dados apresentados pelos aditivos uréia e L. buchneri mais Pediococcus foram ajustados em curvas simples, através de modelos lineares, para descrever e predizer as variações durante a ensilagem. Os tratamentos controle e a aditivação com L. buchneri apenas, pelas altas taxas fermentativas, observaram melhor ajuste dos dados em polinômios de segundo e terceiro grau. Apesar dos altos teores de ácido acético em todas as silagens, principalmente nas silagens aditivadas com a combinação de bactérias, não foram verificadas efeitos deste sobre a população de leveduras. Os teores obtidos de ácido lático e ácido propiônico e a relação entre esses ácidos e o ácido acético, durante a fermentação, conseguiu explicar parte do sucesso dos tratamentos uréia e L. buchneri mais Pediococcus na redução da atividade da enzima álcool desidrogenase e na producão de etanol. A análise de grupamentos hieráquicos mostrou que os aditivos alteraram a diversidade bacteriana durante a ensilagem. / The present trial aimed to study the ensiling associated factors of sugarcane focusing on chemical and microbial additives on fermentation, chemical composition, enzymatic activity of alcohol dehydrogenase and the microflora development and diversity in sugarcane silages. A complete randomized design was set to a 110-d trial with 4 treatments, two replications within 6 opening dates (1, 3, 7, 15, 35, 110-d). Treatments were described as follows: urea 1% (wet basis), Lactobacillus buchneri (3.65x105 cfu/g of forage), a combination of Pediococus pentosassus and Lactobacillus buchneri (1x106). Major variation observed on the chemical composition and the DM losses in sugarcane silages without additives took place from the day 7 through the day 15. Losses of DM and soluble carbohydrates showed similar trend and in opposition to the NDF increase. Gases losses averaged 28.27%, while the soluble carbohydrates and NDF contents reached respectively, 2.98% and 67.77% when fermentation was stabilized. Conversely, ethanol and the digestibility were changed across the storage period up to the day 35, with ethanol content increasing to 12.23%. 1% of ethanol increase was associated with 2 percentage units of digestibility decrease. Both urea and the combination of microorganisms were effective in decrease the ethanol content (2.75, 1.30 vs 8.27% - without additives), decrease DM losses (47 and 60%) and reduce soluble carbohydrates losses (22 and 56%) when compared to the control treatment. The urea treated silages showed higher pH and lactic acid values. The L. buchneri treatment led to higher ethanol content (11.23 vs 8.27%) compared to the control, resulting in low DM recovery rate, higher losses and decreased digestibility as well as the silages without additives. The major changes on the chemical composition were noticed after the day 7 of fermentation. For the addition of urea and the combination of microorganisms L. buchneri and Pediococcus the variation was better described by linear equations whereas quadratic and cubic effects were more suitable for fitting the data from the control and the L. buchneri added silages. Even tough all silages has shown high acetic acid contents, mainly the combination of lactic bacteria, no significant effects were observed upon the yeast counts. However, the levels of lactic acid and propionic acid and the ratio of both over the acetic acid content were related to the decrease on the activity of the alcohol dehydrogenase enzyme and, furthermore, on the ethanol content of the silages. The cluster analysis based on molecular evaluation demonstrated a change promoted over the bacterial population mediated by the additives applied during the ensiling of sugarcane.
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Comparative Analysis Of Product And By-product Distributions In Defined And Complex Media In Serine Alkaline Protease Production By Recombinant Bacillus SubtilisOktar, Ceren 01 September 2003 (has links) (PDF)
In this study, firstly the effects of aspartic acid group amino acids -which were reported to be the potential bottleneck in serine alkaline protease (SAP) synthesis- on SAP production were investigated by substituting at a concentration range of 0-15 mM by using recombinant Bacillus subtilis carrying pHV1434::subC gene. All aspartic acid group amino acids except threonine inhibited SAP activity when CAA& / #8805 / 2.5 mM. The highest SAP activities with asparagine, aspartic acid, lysine, threonine, isoleucine and methionine werefound to be 1.89-, 1.87-, 1.61-, 1.48-, 1.4-, and 1.4-fold higher than the reference medium activity, respectively, when the concentration of each amino acid was CAA=0.25 mM. The product and by-product distributions in defined and complex media in SAP production were also analyzed and compared in order to obtain a depth in-sight on functioning of the metabolic reaction network. The highest SAP activity in complex medium was found to be 3&ndash / fold higher than defined medium activity, while, specific SAP production rate was 1.2- fold higher. The highest cell concentration in complex medium (CX= 14.3 g/dm-3) was 8.1-fold higher than that obtained in defined medium (CX= 1.75 g/dm-3). In both media, oxaloacetic acid was observed extracellularly and intracellularly. In complex medium there was also succinic acid in the extracellular medium indicating that the operation of TCA cycle was insufficient. In both media serine, valine and glycine were observed neither in the extracellular nor in the intracellular media indicating that the synthesis of these amino acids can be a secondary rate limiting step. In defined medium asparagine was present neither in the cell nor in fermentation broth whereas, methionine was observed in the cell in high amounts, probably due to the lower flux values towards asparagine. Thus, in defined medium the synthesis of asparagine can also be a potential bottleneck in SAP production in defined medium.
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Estudo da variação do meio na produção de metabólitos secundários pelo fungo endofítico Aspergillus niger / STUDY OF THE VARIATION OF THE MEANS IN THE PRODUCTION OF SECONDARY METABOLITES BY ENDOPHYTIC FUNGUS ASPERGILLUS NIGER.Araujo, Nailson Correia de 17 December 2010 (has links)
The endophytic fungus Aspergillus niger isolated from specie plant Hancornia speciosa, commonly known as mangabeira, was cultivated in different culture media and used for identification of six substances in their extracts, such as oxalic, citric, tartaric, p-acetylbenzoic, hexylitaconic acids and phyrofen. For quantification of pyrophen in different extracts, it was developed a method by High Performance Liquid Chromatography that was efficient for both extract analysis and fermented broth. The method allowed to evaluate the effect of different media ways and culture time on the pyrophen. The analyzed media for pyrophen production were mangaba juice, Czapeck and potato dextrose broth (PDB) and the highest yield was obtained using mangaba juice. The effect of culture time was evaluated by cultivating the fungus in the PDB medium, being the ideal period of fermentation for pyrophen production was 12 days. / O fungo endofítico Aspergilus niger isolado da espécie vegetal Hancornia speciosa, conhecida popularmente como mangabeira, foi cultivado nos meios suco de mangaba, Czapeck e Caldo de Batata Dextrose (CDB) e levou ao isolamento e identificação de seis substâncias em seus extratos, sendo elas os ácidos oxálico, cítrico, tartárico, p-acetil-benzóico e hexilitacônico e a substância pirofeno. Visando encontrar a melhor condição de cultivo para produção de pirofeno foi desenvolvido um método analítico por Cromatografia Líquida de Alta Eficiência para análise desta substância. O método desenvolvido foi eficiente tanto para análise dos extratos quanto para análise do caldo fermentado e permitiu avaliar o efeito dos diferentes meios e do tempo de cultivo na produção desta substância. A maior produção de pirofeno foi obtida utilizando suco de mangaba como meio de cultivo e o período ideal de fermentação para a produção de pirofeno foi de 12 dias, quando cultivado no meio líquido CDB.
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