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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Desenvolvimento, caracterização e otimização de bebida fermentada simbiótica de soja com farinha de banana verde / Development, characterization and optimization of soybean fermented probiotic drink with green banana flour

Brandão, William Arthur Philip L Naidoo Terroso de Mendonça 08 December 2015 (has links)
Made available in DSpace on 2017-05-12T14:47:27Z (GMT). No. of bitstreams: 1 WILLIAML.pdf: 6327361 bytes, checksum: 3b7e20d66eec97b353761c9d725c803a (MD5) Previous issue date: 2015-12-08 / This work was conducted with the objective of developing and evaluate the physico-chemical, sensory and microbiological quality of fermented beverages by probiotic microorganisms, with water-soluble extract of soybean powder (8, 10, 12%), and 0, 2, 3 and 4 % addition of green banana flour powder, and 12% of sucrose in all formulations, proposing a good development of total lactic acid bacteria , through the investigation of the influence of two variables (different percentages of soy and banana flour) on the total of lactic acid bacteria count , and the physical and chemical aspects, and the sensory acceptance as well. Twelve treatments were developed. Fermented beverages of soybeans were evaluated at pH, lactic acid acidity, moisture, ash, lipids, protein, total carbohydrates, dietary fiber, water activity, fixed mineral residue, enumeration of lactic acid bacteria, total coliform count( 35° C and 45° C), yeast and mould count, sensory acceptance (hedonic scale of nine points). The results were submitted to ANOVA and Tukey test (the significance level 5. The data obtained, showed that the percentage of water-soluble soybean extract influenced in the total count of lactic acid bacteria, mainly in 10 treatments added with this ingredient. The same occurred in the treatments with addition of 1%, 2%, 3% of banana flour powde. Under the microbiological point of view, all samples were able to be consumed, according to the current legislation, during 35 days of storage. The treatment with 10% of soy extract and 3% of banana flour, presented the best results in teh microbiological count of lactic acid bacteria, however when optimized, the behavior were equal among all treatments, changing only the threshold count. Soy has sensory features that limit it´s consumption, as the beany taste and aroma, due to the action of the lipoxigenases enzymes, however, the products developed, in this study, presented a satisfactory acceptability. / Este trabalho foi realizado com o objetivo de desenvolver e avaliar as características físicoquímicas, sensoriais e a qualidade microbiológica de bebidas fermentadas por microorganismos probióticos, elaboradas com 8,10 e 12% de extrato hidrossolúvel de soja em pó, 0, 2, 3 e 4% de farinha de banana verde em pó, e 12% de sacarose em todas as formulações, propondo uma formulação com melhor desenvolvimento de bactérias láticas totais, dada a influência das duas variáveis (diferentes percentuais de soja e farinha de banana) sobre a contagem de bactérias láticas totais, em seus aspectos físico-químicos e sobre a sua aceitação sensorial. Foram desenvolvidos 12 tratamentos. As bebidas fermentadas de soja foram avaliadas quanto ao pH, acidez em ácido lático, umidade, cinzas, lipídios, proteína, carboidratos totais, fibra alimentar, atividade de água, resíduo mineral fixo, enumeração de bactérias láticas totais, contagem de coliformes a 35 ºC e 45 °C, contagem de bolores e leveduras, aceitação sensorial (escala hedônica de nove pontos). Os resultados obtidos, submetidos à ANOVA e ao teste de médias (nível de significância a 5%), revelaram que a porcentagem de adição do extrato hidrossolúvel de soja influenciou na contagem de bactérias láticas totais, principalmente nos tratamentos com 10% de adição do extrato. O mesmo ocorreu nos tratamentos com adição de 1, 2, 3% de farinha de banana em pó, nesta escala. Sob o ponto de vista microbiológico, todas as amostras estavam aptas para serem consumidas, segundo a legislação vigente, durante 35 dias de armazenamento. O tratamento com 10% de extrato de soja e 3% de farinha de banana destacou-se pelos melhores resultados na contagem microbiológica de bactérias láticas, todavia quando otimizado, o comportamento foi igual, alterando apenas o patamar da contagem. Todos os produtos desenvolvidos neste estudo apresentaram uma aceitabilidade satisfatória, com indice superior a 70% para impressão global do produto, o que significa que será bem aceito caso seja lançado no mercado consumidor
122

Doseamento microbiológico de gentamicina por difusão em agar - proposta de delineamento experimental / Microbiological assay of gentamicin sulfate by agar diffusion - proposal of experimental design

Lourenço, Felipe Rebello 18 December 2006 (has links)
A gentamicina é um complexo antibiótico de largo espectro, produzido por actinomicetos do gênero Micromonospora e classificado entre os antibióticos aminoglicosídeos, utilizado no tratamento de infecções graves, devidas a microrganismos Gram-negativos. Alterações da sua atividade antimicrobiana, não demonstradas pelos ensaios químicos, podem ser avaliadas pelos ensaios microbiológicos. O objetivo deste trabalho foi comparar os delineamentos experimentais 5 x 1, 2 x 2 e 3 x 1, avaliando-se os parâmetros de validação de especificidade, linearidade, faixa ou intervalo, precisão e exatidão para cada delineamento experimental em diferentes níveis de concentração, apresentações e lotes. O plano de trabalho constituiu-se na realização de 81 ensaios (em 3 réplicas) de doseamento microbiológico de gentamicina. As concentrações das soluções empregadas foram preparadas numa faixa de 1,0 µg/mL a 5,0 µg/mL, diluídos em tampão fosfato 0,1 M pH 8,0. O meio utilizado foi o meio antibiótico no. 11, com Staphyloccocus epidermidis (ATCC 12228). Empregou-se 21 mL de meio como camada base e 4 mL de meio inoculado à 1% como camada superfície. As placas foram incubadas por 16-18 horas à 37 ± 1 °C. Os três delineamentos empregados apresentaram especificidade adequada para análise de creme dermatológico e solução injetável contendo sulfato de gentamicina. Também apresentaram exatidão e linearidade no intervalo avaliado. Os delineamentos não apresentaram diferença significativa quanto a precisão. Os resultados foram comparados através da determinação de índices de capacidade do sistema de medição. A análise estatística demonstrou que não há diferença significativa entre os resultados obtidos pelos delineamentos 5 x 1, 2 x 2 e 3 x 1, sendo equivalentes e intercambiáveis. / Gentamicin is a broad-spectrum antibiotic complex produced by actinomycetes belonging to Micromonospora genus and classified among aminoglycoside antibiotics, used in the treatment of serious infections derived from Gram-negative microorganisms. Alterations of their antimicrobial activity not shown in chemical assays can be evaluated through microbiological assays. The aim of this work was to compare 5 x 1, 2 x 2 and 3 x 1 experimental designs, evaluating validation parameters of specificity, linearity, range, precision, and accuracy for each experimental design in different levels of concentration, presentation, and lots. It consisted of 81 assays (in 3 replicas) of gentamicin microbiological dosage. The concentrations of the solutions used were employed in a range from 1.0 µg/ml to 5.0 µg/ml, diluted in phosphate buffer 0.1 M pH 8.0. Antibiotic medium number 11 was used, with Staphyloccocus epidermis (ATCC 12228)21ml of medium were used as base layer and 4 ml of medium inoculated at 1% were used as surface layer. The plates were incubated for 16-18 hours at 37 ± 1 ºC. The three designs employed showed adequate specificity for analysis of dermatological cream and injectable solution containing gentamicin sulphate. They also showed accuracy and linearity in the range evaluated, but not a significant difference concerning precision. The results were compared by means of the determination of the rates of measurement system capacity. The statistical analysis demonstrated that there is no significant difference among the results obtained.
123

Engineered bacteria for the modulation of intestinal physiology, inflammation, and behavior along the microbiome-gut-brain axis

Cusimano, Frank Anthony January 2019 (has links)
Bacteria in the gastrointestinal tract play an important role in intestinal motility, inflammation, homeostasis, and behavior. Bacteria, through the natural synthesis of neuroactive compounds and secondary metabolites, can modulate the host immune system and communicate with the host along the signaling pathway along the gut-brain axis. Here, we functionally design, develop, test, and characterize a platform for the study of microbial-host interactions using advancements in the field of synthetic biology. First, we describe the engineering of Escherichia coli Nissle to biosynthesize serotonin within the mammalian gut using a native-plasmid optimized approach. Serotonin is crucial for neurotransmission throughout the body and may be playing a role in microbial gut-brain communication. In the gastrointestinal tract, serotonin regulates intestinal motility, cell turnover, intestinal inflammation, and gastrointestinal homeostasis. Upon serial daily oral gavages, our engineered bacterium populates a murine colon to produce serotonin locally in the mucosa layers along the epithelial lining. Changes in host physiology were observed including decreased gastrointestinal motility, increased colonic Muc2 expression, induction of host TPH2, responsible for serotonin biosynthesis in enteric neurons, and upregulation of serotonin receptors HTR3, HTR4, and HTR7 in the colon. Behavioral tests revealed a statistically significant decrease in anxiety and depression in stress-induced environments in mice treated with the engineered bacterium. This work suggests that gut bacteria engineered to modulate host gut-brain axis may have both scientific and clinical uses to study microbial-host interactions and treat gastrointestinal and behavioral mood disorders in humans. Second, we engineered bacteria to produce exogenous butyrate and other SCFAs in the murine gut. Short chain fatty acids (SCFAs) play an important role in intestinal homeostasis, fluid dynamics, inflammation, oxidative stress, and intestinal hypersensitivity and motility. With this development, we characterized the effects of our butyrate-producing bacteria on a high-fat diet and DSS-induced colitis model within the colon. Although energetically burdensome to produce, our strains produced butyrate in the colon at higher density in an actively inflamed colitis model. After 14 days of oral administration, our engineered strain (EcN:B) increased the colon length of normal wild-type mice, in high fat fed mice, and in mice with recovering and actively inflamed DSS-induced colitis. EcN:B increased mucosal barrier thickness, upregulated gene expression of the barrier integrity markers Cldn1, Ocln, Zo1, and altered crypt and villus height during inflammation recovery. Furthermore, as butyrate is known to induce Foxp3+ Regulatory T cells, we saw a 13.01% percent increase in Foxp3+ cells in the colon of mice fed our engineered bacteria. This work suggests that synthetic gut bacteria engineered to produce short chain fatty acids may have future clinical uses to treat patients with inflammatory bowel disease including Crohn’s and Colitis with future potential to serve as a therapeutic for irritable bowel syndrome, idiopathic constipation, obesity, and colorectal cancer. This platform, with the use of synthetic biology to natively engineer Escherichia coli Nissle to produce bioactive compounds in the distal gastrointestinal tract, creates a framework for future characterization of bacterial-host communication and future microbial-based therapeutics.
124

Microbiological, Therman Inactivation, and Sensory Characteristics of Beef Eye-of-Round Subprimals and Steaks Processed with High-Pressure Needleless Injection

Jefferies, Laura Kahealani 01 May 2011 (has links)
High-pressure needleless injection (HPNI) is a process where small-diameter, high-velocity burst of liquid, penetrate foods at pressures ≤ 10,000 psi. The potential of HPNI as an enhancing technique for meat was studied. In study 1, HPNI translocated surface E. coli O157 into the interior of beef eye-of-round subprimals with an incidence of 40 (±7), 25 (±8), and 25 (±8)% for meat that had been surface-inoculated with a four-strain cocktail at 0.5, 1, and 2 log10 CFU/cm2, respectively. Run-off water contained 2, 2, and 3 log10 CFU/ml and was used for HPNI of additional subprimals, which resulted in a cross-contamination incidence of 83 (±4), 60 (±15), and 37 (±6) %, respectively. Incidence of translocation and cross-contamination was similar at all sampled levels below the inoculated surface. Study 1 results indicate that surface microflora will be translocated from the surface into the interior of HPNI-treated beef by the injection fluid and by cross-contamination with recycled fluid. In study 2, E. coli was undetected in cooked steaks (63˚C internal) cut from subprimals inoculated with 2 log10 CFU/cm2 and HPNI processed (study 1). Although cooking reduced E. coli counts, determination of complete kill was not possible because the detection limit for bacterial recovery was about 1 log10 CFU/g. Steaks cut from HPNI-processed subprimals took longer (p <0.05) to reach 63˚C with grilling or broiling, compared to control steaks, possibly due to increased moisture in enhanced steaks. In study 3, sensory acceptance of steaks was evaluated by a consumer panel. Appearance, flavor, and overall acceptance were similar among the untreated control, HPNI steaks, blade tenderized steaks (BT steaks), and steaks cut from subprimals that had been needle-injected with 0.35% (wt/vol) sodium tripolyphosphate using needle injection (NI-subprimal steaks) or HPNI (HPNI-subprimal steaks). Texture of BT steaks (6.5±1.9) was more liked than control steaks (5.8±1.8), while texture was similar for all other comparisons. Conversely, Warner-Bratzler shear force was NI-subprimal steaks < control < HPNI steaks = HPNI-subprimal steaks = BT steaks. Lack of correspondence between texture acceptance data and WBSF suggests that sensory scores were influenced by factors other than the force required for mechanical shear.
125

Selected Physio-Chemical, Microbiological, and Agronomical Studies on the Controlled Atmosphere Storage of Sugarbeet (Beta Vulgaris) Roots

Karnik, Vinod V. 01 May 1970 (has links)
The post-harvest physiology of sugarbeet (Beta vulgaris) roots was studied during controlled atmosphere (CA) storage at 35° and 50°F. Zero, 3, 6 and 10% carbon dioxide and 5% oxygen concentrations were employed to investigate the most beneficial concentrations of gases. Under the experimental conditions beets were stored successfully for 200 days. The maximum beneficial effects of CA were observed under 6% carbon dioxide and 5% oxygen at 35°F. Regardless of storage temperatures , sucrose retention was highest in the beets stored under CA, compared to conventional refrigeration (CR). Other beneficial effects include less hydrolysis of sucrose to reducing sugars and a decrease in raffinose accumulation. Fungal growth and sprouting were also inhibited significantly, under CA. In the second phase of the studies, investigations were conducted on sugarbeets to study the effects of different levels of nitrogen fertilizer on the optimum CA storage at 40°F. Regardless of the level of nitrogen fertilization, the beets stored under CA demonstrated beneficial effects as described earlier. In addition, respiration, measured on the whole beets, and amino nitrogen content of the beets were lower in the CA-stored beets than those stored under CR. Accumulation of citric acid and succinic acid was significant in the CA-stored beets.
126

Aplicabilidade de métodos alternativos no monitoramento da qualidade microbiológica da água tratada para diálise / Applicability of alternative methods for the monitoring microbiological quality of treated water for dialysis

Carvalho, Gabriela Corrêa 08 August 2019 (has links)
A fim de garantir a qualidade final de produtos os laboratórios de análise microbiológica fornecem dados sobre a qualidade dos mesmos em todas as suas etapas de produção. A crescente preocupação com a saúde dos pacientes conduz à busca de métodos que forneçam resultados precisos e rápidos, pois possibilitam que ações corretivas sejam tomadas em tempo real. O presente trabalho teve por objetivo avaliar o potencial de tecnologia alternativa no monitoramento de endotoxina bacteriana na água tratada para diálise e dialisato e avaliar o potencial da citometria de fluxo na análise de água. Para isso utilizou-se Portable Test System (PTS®) como método alternativo para detecção de endotoxina bacteriana no monitoramento da água tratada para diálise e dialisato, o qual foi validado frente ao método convencional farmacopeico. Paralelamente realizou-se revisão narrativa da literatura a fim de avaliar a aplicabilidade da citometria de fluxo em análises de água. A análise dos diferentes parâmetros de validação para endotoxina bacteriana no método alternativo mostrou que, exceto para a menor diluição analisada, houve linearidade e precisão nos resultados. Por outro lado a concentração de 0,25 UE/mL foi a menor que apresentou exatidão e especificidade. Observou-se ainda, que o limite de detecção foi de 0,125UE/mL e o de quantificação de 0,25 UE/mL, portanto o intervalo foi de 0,25-1,0 UE/mL. Adicionalmente pela análise de resistência pode-se perceber que ao variar analistas não houve diferença significativa. Em relação ao tempo de análise em uma condição de rotina laboratorial com muitas amostras, o PTS® mostrou-se demorado. Ressalta ainda, que seria importante que a legislação vigente deternimasse a análise mensal de endotoxinas no dialisato. A revisão da literatura evidencia o potencial da tecnologia de citometria de fluxo, pois a mesma mostrou-se satisfatória quando comparada a metodologias convencionais para análise de água. O trabalho desenvolvido permitiu concluir que o PTS®) mostrou-se adequado para analisar amostras in loco, permitindo análises em tempo real, que para as quais haja a expectativa de ausência de endotoxinas ou de concentração respeitando o intervalo de 0,25 UE/mL a 1,0 UE/mL. Quanto a citometria de fluxo, esta mostrou-se uma tecnologia promissora em analisar amostras de água, sendo portanto recomendável proceder a estudos de validação e aplicabilidade. / In order to guarantee the final quality of products, the microbiological analysis laboratories provide data about their quality at all production stages. The growing concern for patients\' health leads to the search for methods that provide accurate and fast results, as they enable corrective actions to be taken in real time. The present work aimed to evaluate the alternative technology potential in the monitoring of bacterial endotoxin in treated water for dialysis and dialysate and to evaluate the potential of flow cytometry in water analysis. The different validation parameters analysis for bacterial endotoxin in alternative method showed that, except for the lowest dilution analyzed, there was linearity and precision in the results. On the other hand, the concentration of 0.25 EU / mL was the lowest that presented accuracy and specificity. It was further observed that the detection limit was 0.125UE / mL and the quantification limit was 0.25 EU / mL, so the range was 0.25-1.0 EU / mL. Additionally by the ruggedness analysis it was possible to perceived that when varying analysts there was no significant difference. Regarding the analysis time in a laboratory routine condition with many samples, the PTS® was was time consuming. It was also observed that it would be important to determine monthly analysis of endotoxins in dialysate. The literature review evidence the flow cytometry technology potential of the because it was satisfactory when compared to conventional methodologies for water analysis. The research showed that the PTS® was suitable for analyzing samples in loco, allowing real-time analyzes, for which there is expectation of endotoxins absence or concentration respecting the range of 0.25 EU / mL to 1.0 EU / mL. For the flow cytometry, it was shown to be a promising technology for analyzing water samples, and it is therefore advisable to carry out validation and applicability studies.
127

Size Dependent Antimicrobial Properties of Sugar Encapsulated Gold Nanoparticles

Vangala, Lakshmisri Manisha 29 May 2012 (has links)
The antimicrobial properties of dextrose encapsulated gold nanoparticles (dGNPs) with average diameters of 25 nm, 60 nm, and 120 nm (± 5 nm) synthesized by green chemistry principles were investigated against both Gram-negative and Gram-positive bacteria. Studies were performed involving the effect of the dGNPs on the growth, morphology and the ultrastructural properties of bacteria. dGNPs were found to have significant dose dependent antibacterial activity which was directly proportional to their size and also their concentration. The microbial assays revealed the dGNPs to be bacteriostatic as well as bactericidal. The dGNPs exhibited their bactericidal action through the disruption of the bacterial cell membrane causing leakage of cytoplasmic content. The overall outcomes of this study suggest that dGNPs hold promise as a potent antimicrobial agent against a wide range of disease causing bacteria and can control and prevent possible infections or diseases.
128

Effect Of High Hydrostatic Pressure On Microbial Load And Quality Parameters Of Grape Juice

Mert, Mecnun 01 January 2010 (has links) (PDF)
Effect of high hydrostatic pressure (150-200-250 MPa) on the microbial load and quality parameters (pH, color, 5-hydroxymethylfurfural-HMF) of white (Sultaniye) and red (Alicante Bouschet) grape juices with combination of temperature (20-30-40&deg / C) and holding time (5-10-15 min) was studied. Increased pressure and temperature showed significant effect on microbial reduction in white and red grape juices (p&lt / 0.05). The effect of pressure and time on pH drop was found to be insignificant (p&gt / 0.05). HHP resulted in E&lt / 1 for white grape and E&lt / 7 for red grape juice samples. Shelf life analysis for HHP treated white grape juice (200 MPa-40&deg / C-10min) and red grape juice (250 MPa-40&deg / C-10min) revealed no microbial growth up to 90 days when stored at 25&deg / C. Although HMF formation was observed in industrially manufactured, pasteurized samples (65&deg / C for 30 min), no HMF was detected in HHP treated white and red grape juices. HHP at the suggested conditions can be recommended as a better production alternative to heat treatment for white and red grape juice with respect to microbial load and studied quality parameters even at temperatures lower than required for pasteurization.
129

An Influence of Cultivar and Growing Technology upon Chemical Composition and Biological Activity of Sprouted Wheat / Veislės ir auginimo technologijų įtaka daigintų kviečių cheminei sudėčiai ir biologiniam aktyvumui

Kraujutienė, Ingrida 17 December 2007 (has links)
There is the first time when there have been compared an activity of enzymes such as α- and β-amylase, maltase, xylanase, cellulase, catalase and protease, the quantity of vitamins C and E and alterable and inalterable amino acids and the value of energy of separate wheat grain cultivars 'Širvinta 1' and 'Zentos' grown up following separate technologies and thereafter sprouted. Germinated wheat grain have been used for producing new fermented milk products when biochemical composition and microbiological pollution have been in-vestigated. / Pirmą kartą buvo nustatytas ir palygintas pagal skirtingas technologijas išaugintų, o po to daigintų kviečių veislių 'Širvinta 1' ir 'Zentos' grūdų α- ir β-amilazių, maltazės, ksilanazės, celiulazės, katalazės, proteazių fermentų aktyvumas, C ir E vitaminų, pakeičiamųjų ir nepakeičiamųjų aminorūgščių kiekiai ir energinė vertė. Pirmą kartą įvertinus ekologiškai augintų, daigintų kviečių biocheminę sudėtį, mikromicetinę ir bakterinę taršą, jie panaudoti naujiems rauginto pieno produktams kurti.
130

Kai kurių geriamo vandens mikrobiologinių rodiklių įvertinimas / Evaluation of microbiological quality of drinking water

Kasnauskytė, Neringa 16 March 2006 (has links)
Aim of study: to evaluate microbiological quality of drinking water according Lithuanian drinking water standard HN 24:2003. Material and methods. The data of microbiological tests of drinking water were collected from laboratories responsible of drinking water control in Kaunas region. Part of the study was carried out at Helsinki University (dep. of Food and Environmental Hygiene). Different microbiological criteria of drinking water samples from small community supply were examined. Results. The results of our study showed that 94.4 % of drinking water from centralist drinking water supplies in Lithuania fulfill requirements of drinking water standard HN 24:2003 and is safe to drink. Drinking water from dug wells more often are contaminated and does not fit drinking water standard requirements. We found that there were too much coliforms in 12,8 % of drinking water samples, enterococci in 23.4% and E. coli in 16.7 % respectively. The study showed that there is a season variation of microbiological quality of drinking water. Less microbiological contamination of dinking water samples was during winter season from both water supply systems - centralist drinking water supplies and small community supplies. Microbiological quality of drinking water in Lithuania from small community supplies was worse compare to drinking water from small community supplies in Finland. The average of E.coli bacteria in Lithuanian drinking water from small community supplies was 5.57±2,09/10... [to full text]

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