Orientador: Caroline Joy Steel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-23T10:09:24Z (GMT). No. of bitstreams: 1 Rodrigues_CinthiaSoares_M.pdf: 2848359 bytes, checksum: e2cefcd39026a0a746d80f4ba1f784b9 (MD5) Previous issue date: 2013 / Resumo: As barras de cereais surgiram como uma alternativa aos confeitos tradicionais e apresentam alto potencial de inovação, possibilitando a incorporação de ingredientes funcionais. As barras de cereais são produtos de grande interesse comercial por sua facilidade de consumo, além do apelo de saudável e de ser fonte de fibras. Com o advento dos alimentos funcionais, surgiu o interesse em se avaliar o comportamento das barras de cereais com ingredientes funcionais como as fibras prebióticas e as culturas probióticas, objetivo final deste estudo. Foram considerados aspectos nutricionais, de qualidade microbiológica e sensorial. Inicialmente, foi estudado o perfil das barras de cereais comerciais para direcionar a elaboração de novas formulações e foi verificado os baixos índices de fibras e diferenças nos parâmetros de textura e umidade, devido à grande variabilidade de ingredientes utilizados. Definida uma formulação controle, as concentrações de fibras prebióticas (inulina e fruto-oligossacarídeos) foram avaliadas por meio de delineamento composto central rotacional (DCCR), tendo como variáveis respostas os parâmetros: atividade de água, firmeza instrumental e umidade. As formulações com teores de fibras prebióticas superiores a 3,5 % foram analisadas sensorialmente e estiveram na região de aceitação positiva, entre gostei ligeiramente (6,0) e gostei muito (8,0). A formulação prebiótica com 10,5 % de fibras, similar (p = 0,05) em aceitação à formulação controle, foi selecionada para a adição da cultura probiótica na tentativa de se elaborar uma barra de cereais simbiótica. Análises físico-químicas e microbiológicas foram realizadas ao longo de 60 dias de armazenamento. A tentativa de fornecer probióticos em uma matriz de cereais enfrentou desafios durante o processamento e armazenamento do produto final, ficando as barras de cereais com quantidades viáveis para a alegação probiótica, apenas por 15 dias / Abstract: Cereal bars have emerged as an alternative to traditional confectionery and have a high potential for innovation, enabling the incorporation of functional ingredients. Cereal bars are products of great commercial interest for their ease of consumption and the possibility of incorporating ingredients, besides their health and source of fiber appeal. With the advent of functional foods, the interest in assessing the behavior of cereal bars with functional ingredients such as prebiotic fibers and probiotic cultures, ultimate goal of this study, increased. The nutritional, microbiological and sensory quality of the cereal bars was considered. Initially, the profile of commercial cereal bars was studied to drive the development of new formulations. Low levels of dietary fiber and differences in the parameters of texture and moisture, due to the great variability of ingredients used, were found. A control formulation was defined and the concentrations of prebiotic fibers (inulin and fructo-oligosaccharides) were evaluated by means of a central composite rotational design (CCRD), having as response variables the quality parameters: water activity, instrumental firmness and moisture. Formulations with prebiotic fiber content higher than 3.5% were analyzed sensorially and were in the region of positive acceptance between "liked slightly¿ (6.0) and "liked very much¿ (8.0). The prebiotic formulation with 10.5% dietary fiber, similar (p = 0.05) in acceptance to the control formulation, was selected for the addition of the probiotic culture in an attempt to develop a symbiotic cereal bar. Physical-chemical and microbiological analyzes were carried out over 60 days of storage. The aim of providing probiotics in a matrix of grains presented challenges faced during processing and storage of the final product, concluding that the cereal bars had viable quantities to claim as probiotic only for 15 days / Mestrado / Tecnologia de Alimentos / Mestra em Tecnologia de Alimentos

Conjugated linoleic acid (CLA) has gained much attention recently due to its beneficial health and biological effects on animals and humans. However, the CLA-forming enzyme system has not been studied in details. Six strains of Lactobacillus acidophilus L11, L12, L14, L15, Lactobacillus fermentum and Lactobacillus reuteri were used to study the growth conditions and the production of CLA-forming enzyme in MRS media containing linoleic acid concentrations at 37°C. The purification and characterization of a CLA-forming enzyme were reported for the first time. The results showed that this enzyme has a molecular mass of 72 kDa, and is composed of two subunits. The optimal pH and temperature were 7.0 and 37°C, respectively. Kinetic study indicated that the enzyme has a high affinity for linoleic acid having a Km value of 1.49 x 10 -5 M and the Vmax was 17.1 muM/mg/min. The enzyme activity was inhibited by the metal chelators. (Abstract shortened by UMI.)

Made available in DSpace on 2014-06-11T19:32:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-07-29Bitstream added on 2014-06-13T20:04:33Z : No. of bitstreams: 1 000757820.pdf: 10700274 bytes, checksum: 33a8d0ab3adfab16a9b9b24071f36f03 (MD5) / As interações entre fungos e bactérias são abundantes na natureza e tem importância médica e ambiental. O desenvolvimento adequado de modelos in vitro e in vivo para caracterizar essas interações é essencial para o entendimento do desenvolvimento da doença e descoberta de novas estratégias terapêuticas. O objetivo desse estudo foi avaliar as interações entre Lactobacillus acidophilus e Candida albicans em modelos de estudo in vitro e em modelo experimental de invertebrado. No estudo in vitro, foram avaliados os efeitos de L. acidophilus sobre a formação de biofilme por C. albicans e sobre a capacidade de filamentação de C. albicans. Em ambos os testes, foram avaliados os efeitos diretos das células de L. acidophilus sobre C. albicans e também os efeitos indiretos, utilizando apenas o sobrenadante da cultura de Lactobacilos. Além disso, foram testados os efeitos de L. acidophilus sobre C. albicans em diferentes fases de crescimento da cultura bacteriana (4, 6, 18 e 24 h). Para a realização do estudo in vivo, as cepas de L. acidophilus foram inoculadas juntamente com C. albicans em lagartas de Galleria mellonella para indução de infecção experimental. Os efeitos de L. acidophilus sobre a candidose experimental foram avaliados pela análise de curva de sobrevivência de G. mellonella, quantificação de UFC/mL de C. albicans e avaliação histológica da filamentação de C. albicans nos tecidos do hospedeiro. Os resultados dos testes in vitro e da contagem de UFC/mL em G. mellonella foram submetidos à Análise de Variância e teste de Tukey. Os dados obtidos na curva de sobrevivência de G. mellonella foram analisados pelo método de Log-rank. (P ≤ 0,05). Os resultados in vitro demonstraram que a cultura de 24 h de L. acidophilus foi capaz de inibir a formação de biofilme e a filamentação por C. albicans. Esses efeitos inibitórios também foram observados... / Interactions between fungi and bacteria are abundant in nature and are of medical and environmental importance. The developments of adequate models in vitro and in vivo to characterize these interactions are essential to understand diseases and to discover new therapeutic strategies. The aim of this study was to evaluate the microbial interactions between Lactobacillus acidophilus and Candida albicans on in vitro study models and experimental models of invertebrates. In the in vitro study, we analyzed the effects of L. acidophilus on C. albicans biofilm formation as well as its filamentation ability. On both tests, the direct effects of L. acidophilus cells and indirect effects of the supernatant culture of L. acidophilus were evaluated , as well as the L. acidophilus effects on C. albicans at different bacterial culture growth stages (4, 6 18 and 24h). To perfom the in vivo study, L. acidophilus and C. albicans strains were inoculated in Galleria mellonella model to induce experimental infection. The L. acidophilus effects on experimental candidosis have been evaluated by the analysis of the survival killing curve of G. mellonella, quantify C. albicans colony forming units per millimeter (CFU/mL) and through histological evaluation of C. albicans filamentation ability on the host tissues. The in vitro test results and the CFU/mL number in G. mellonella were submitted to ANOVA and Tukey’s test. The obtained data on G. mellonella killing curves have been analyzed using the long-rank test method. A 5% significance level has been considered on all tests. The in vitro results showed that the L. acidophilus 24 hour culture was able to inhibit the formation of biofilm and filamentation by C. albicans. These inhibitory effects were also observed when the supernatant of the L. acidophilus culture was placed in contact with C. albicans, suggesting that the inhibitory action occurred by the ....

Made available in DSpace on 2014-12-02T11:16:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-03-26Bitstream added on 2014-12-02T11:21:10Z : No. of bitstreams: 1 000796429.pdf: 3598133 bytes, checksum: 33ed808e42b93c105bcf8466893881c3 (MD5) / Tem sido demonstrado que a carbodiimida (EDC) apresenta notável potencial inibidor de proteases (MMPs) e de melhorar as propriedades mecânicas do colágeno quando aplicada sobre a dentina desmineralizada. Entretanto, não existem informações a respeito de sua ação antimicrobiana sobre microrganismos comumente encontrados em lesões de cárie ou mesmo após a sua remoção. Objetivo: Investigar a atividade antimicrobiana do EDC em diferentes concentrações sobre microrganismos presentes em cavidades cariosas. Métodos: Soluções de EDC foram preparadas e testadas contra S. mutans e sobrinus, L. acidophilus e Candida albicans. Inicialmente, foi utilizado o teste de difusão em ágar, no qual discos de papel filtro foram impregnados com EDC 2, 1, 0,5, 0,3 ou 0,1 mol/L, clorexidina 0,12%, nistatina 1% ou tampão Sorensen pH 6,2 (n=6). Em seguida, foi determinada a concentração inibitória mínima (CIM) e bactericida mínima (CBM) do EDC sobre L. acidophilus em suspensão planctônica (n=9), por meio de turvamento. Por fim, a atividade do EDC (de 0,01 à 2 mol/L) sobre L. acidophilus em biofilme monoespécie foi definida por meio do ensaio de XTT (n=6). Os dados foram submetidos aos testes estatísticos de ANOVA e Tukey ou Mann-Whitney (p<0,05). Resultados: No teste de difusão em ágar, nenhuma atividade antimicrobiana foi observada para EDC nas concentrações de 0,1 e 0,3 mol/L, assim como para o grupo controle. EDC 0,5, 1 e 2 mol/L exerceu efeito antimicrobiano apenas sobre L. acidophilus. A CIM do EDC foi de 0,01 mol/L e a CBM foi de 0,03 mol/L. Todas as concentrações de EDC igual ou superiores a 0,05 mol/L foram capazes de reduzir significantemente o metabolismo do biofilme formado por L. acidophilus. Essa redução variou de 84,2 para 0,05 mol/L até 93,4% para 2 mol/L. Conclusão: O EDC apresentou atividade antimicrobiana apenas contra L. acidophilus reduzindo significantemente o crescimento deste microrganismo quando em suspensão... / It has been demonstrated that carbodiimide (EDC) is a potent protease inhibitor (MMPs) and is able to improve the mechanical properties of collagen when applied on the demineralized dentin. However, there is no information about its antimicrobial effect on microorganisms commonly found in caries lesions or even after its removal. Objective: To investigate the antimicrobial activity of different concentrations of EDC against microorganisms present in caries lesions. Methods: EDC solutions were prepared and tested against S. mutans and sobrinus, L. acidophilus and Candida albicans. Initially, the agar diffusion test was used, where paper discs were impregnated with 2, 1, 0.5, 0.3 or 0.1 mol/L EDC, 0.12% chlorhexidine, nistatin 1% or Sorensen’s buffer pH 6.2 (control) (n=6). Then, the minimum inhibitory (MIC) and bactericide concentrations (MBC) of EDC were determined against L. acidophilus using turbidity. Finally, the growth inhibitory activity of EDC (from 0.01 to 2 mol/L) against L. acidophilus in monoespecies biofilm was defined using the XTT assay (n=6). Data were submitted to ANOVA and Tukey tests or Mann-Whitney (p<0.05). Results: For the agar diffusion test, lack of antimicrobial activity was seen for EDC at 0.1 and 0.3 mol/L, as well as for the control group. 0.5, 1 and 2 mol/L EDC exerted a growth inhibitory effect only against L. acidophilus. The MIC for EDC was set as 0.01 mol/L and the MBC as 0.03 mol/L. Concentrations equal to or greater than 0.05 mol/L were capable of significantly reducing the metabolism of L. acidophilus when in monospecies biofilm. This reduction ranged from 84.2% for 0.05 mol/L to 93.4% for 2 mol/L. Conclusion: EDC exerted antibacterial activity only against L. acidophilus significantly reducing its growth in planktonic suspension and its metabolism in biofilms in the concentration of 0.05 mol/L or higher.

Orientador: Juliana Campos Junqueira / Co-orientador: Olavo Cardoso Jorge / Banca: Ana Marisa Fusco Almeida / Banca: Mariella Vieira Pereira Leão / Banca: Luciane Dias de Oliveira / Resumo: As interações entre fungos e bactérias são abundantes na natureza e tem importância médica e ambiental. O desenvolvimento adequado de modelos in vitro e in vivo para caracterizar essas interações é essencial para o entendimento do desenvolvimento da doença e descoberta de novas estratégias terapêuticas. O objetivo desse estudo foi avaliar as interações entre Lactobacillus acidophilus e Candida albicans em modelos de estudo in vitro e em modelo experimental de invertebrado. No estudo in vitro, foram avaliados os efeitos de L. acidophilus sobre a formação de biofilme por C. albicans e sobre a capacidade de filamentação de C. albicans. Em ambos os testes, foram avaliados os efeitos diretos das células de L. acidophilus sobre C. albicans e também os efeitos indiretos, utilizando apenas o sobrenadante da cultura de Lactobacilos. Além disso, foram testados os efeitos de L. acidophilus sobre C. albicans em diferentes fases de crescimento da cultura bacteriana (4, 6, 18 e 24 h). Para a realização do estudo in vivo, as cepas de L. acidophilus foram inoculadas juntamente com C. albicans em lagartas de Galleria mellonella para indução de infecção experimental. Os efeitos de L. acidophilus sobre a candidose experimental foram avaliados pela análise de curva de sobrevivência de G. mellonella, quantificação de UFC/mL de C. albicans e avaliação histológica da filamentação de C. albicans nos tecidos do hospedeiro. Os resultados dos testes in vitro e da contagem de UFC/mL em G. mellonella foram submetidos à Análise de Variância e teste de Tukey. Os dados obtidos na curva de sobrevivência de G. mellonella foram analisados pelo método de Log-rank. (P ≤ 0,05). Os resultados in vitro demonstraram que a cultura de 24 h de L. acidophilus foi capaz de inibir a formação de biofilme e a filamentação por C. albicans. Esses efeitos inibitórios também foram observados... / Abstract: Interactions between fungi and bacteria are abundant in nature and are of medical and environmental importance. The developments of adequate models in vitro and in vivo to characterize these interactions are essential to understand diseases and to discover new therapeutic strategies. The aim of this study was to evaluate the microbial interactions between Lactobacillus acidophilus and Candida albicans on in vitro study models and experimental models of invertebrates. In the in vitro study, we analyzed the effects of L. acidophilus on C. albicans biofilm formation as well as its filamentation ability. On both tests, the direct effects of L. acidophilus cells and indirect effects of the supernatant culture of L. acidophilus were evaluated , as well as the L. acidophilus effects on C. albicans at different bacterial culture growth stages (4, 6 18 and 24h). To perfom the in vivo study, L. acidophilus and C. albicans strains were inoculated in Galleria mellonella model to induce experimental infection. The L. acidophilus effects on experimental candidosis have been evaluated by the analysis of the survival killing curve of G. mellonella, quantify C. albicans colony forming units per millimeter (CFU/mL) and through histological evaluation of C. albicans filamentation ability on the host tissues. The in vitro test results and the CFU/mL number in G. mellonella were submitted to ANOVA and Tukey's test. The obtained data on G. mellonella killing curves have been analyzed using the long-rank test method. A 5% significance level has been considered on all tests. The in vitro results showed that the L. acidophilus 24 hour culture was able to inhibit the formation of biofilm and filamentation by C. albicans. These inhibitory effects were also observed when the supernatant of the L. acidophilus culture was placed in contact with C. albicans, suggesting that the inhibitory action occurred by the .... / Doutor

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Ingeniera Civil Química / Ingeniera Civil en Biotecnología / El presente trabajo tiene por objetivo el estudio de la acción catalítica del microorganismo termófilo moderado Sulfobacillus acidophilus en la biolixiviacion de calcopirita a 45ºC, con el fin de demostrar una mayor tasa de recuperación de cobre al elevar la temperatura de operación. Con este objeto, se realizó un estudio comparativo de la biolixiviación de calcopirita por un microorganismo mesófilo Acidithiobacillus ferrooxidans y el microorganismo Sulfobacillus acidophilus. El estudio consistió en la biolixiviación de un concentrado de calcopirita en frascos agitados a 30 y 45ºC para los cultivos mesófilo y termófilo moderado, respectivamente. Los frascos fueron monitoreados periódicamente por un periodo de 648 horas, para la medición de Eh, pH, Fe(II) y Fe total en solución, fierro precipitado, sulfato y cobre en solución. Las poblaciones de bacterias de ambos microorganismos (planctónicas y adheridas a los minerales) se cuantificaron utilizando tinción con DAPI y su evaluación en un microscopio de epifluorescencia. Además, mediante el análisis de los datos obtenidos de cobre en solución se determinaron las tasas de recuperación, y las respectivas etapas controlante del proceso según el modelo del núcleo sin reaccionar. Los resultados mostraron para ambas cepas una alta capacidad de adherencia sobre la calcopirita de aproximadamente 85%. Sin embargo, el porcentaje de recuperación de cobre y el tiempo de disolución total de la calcopirita () muestra una diferencia apreciable entre los cultivos. Se obtuvo un porcentaje de recuperación de 7,3% y 13,3% y valores de  de 20.833 y 6.944 días para A. ferrooxidans y S. acidophilus, respectivamente. Los resultados obtenidos permiten concluir que S. acidophilus no fue capaz de aumentar la tasa de recuperación de cobre, lo que se evidenció por obtener una tasa menor a la obtenida en el experimento control (sin microorganismo), a la misma temperatura de estudio. Esto debido a la mayor precipitación de jarositas en el cultivo inoculado, lo que pasivó el mineral. Estos resultados darían cuenta que los experimentos con S. acidophilus corresponderían a una lixiviación química y el aumento de éste rendimiento se atribuye al aumento de la temperatura de 30 a 45ºC, lo que aceleraría la reacción química.

The regulatory standards set by food authorities globally for probiotic foods such as Cheddar cheese makes it essential to have reliable enumeration media that will accurately monitor the survival of probiotic bacteria over the shelf life of Cheddar cheese. This study therefore investigated various selective and differential media for reliable enumeration of Lactobacillus acidophilus, Bifidobacterium spp., starter lactic acid bacteria (SLAB) and non-starter lactic acid bacteria (NSALB) from Cheddar cheese using pure cultures and commercial probiotic Cheddar cheese. All media showed variation in counts and selectivity. Some reported selective media failed to inhibit SLAB and NSLAB. The media that were reliable and also gave good recovery were, Reinforced Clostridium Agar with Bromocresol green and Clindamycin (RCABC), which was selective for L. acidophilus spp. and Reinforced Clostridium Agar with Aniline blue and Dicloxacillin (RCAAD), which was differential for Bifidobacterium spp. and SLAB. Reinforced Clostridium Agar with Bromocresol green and Vancomycin (RCABV) was found suitable for NSLAB. Additionally, an enzyme based colorimetric assay was modified successfully and used as a confirmatory test to check the presence of bifidobacterial colonies on enumeration media. Six batches of probiotic Cheddar cheese were manufactured with the incorporation of LAFTI L10 (L. acidophilus) and LAFTI B94 (B. lactis). The survival of probiotic bacteria, SLAB and NSLAB were monitored over a six-month ripening period using the selected media. The survival of free probiotic bacteria throughout the ripening process decreased consistently in all the six batches. In order to enhance the survival of probiotic bacteria, the effect of microencapsulation on the viability of LAFTI L10 and LAFTI B94 in Cheddar cheese was studied. Six batches of Cheddar cheese were manufactured with the incorporation of alginate-starch encapsulated and free cells of LAFTI L10 and LAFTI B94. The survival of both the encapsulated and free probiotic bacteria was studied over a six month ripening period. The survival of encapsulated LAFTI L10 and LAFTI B94 (107 cfu/g) was found to be significantly better than that of free bacteria (105 cfu/g) at the end of six months of ripening period in Cheddar cheese. / Master of Applied Science (M. App. Sci.) (Biotechnology)

Norbert Pfennig, a German microbiologist, isolated the first true acidophilic purple bacterium in 1969. He named the organism Rhodoblastus acidophilus. Since the original work of Pfennig, no study has examined the phylogeny and physiology of the original strains of R. acidophilus or isolated any new strains. In this thesis six new strains of acidophilic purple nonsulfur bacteria were isolated from a Canadian Sphagnum peat bog. Moreover, three original Pfennig strains of R. acidophilus and two uncharacterized strains (previously isolated by Michael Madigan) were included in experiments aimed to describe the new isolates and further our understanding of the species Rhodoblastus acidophilus. Although pigmentation varied, all of the strains studied were very similar. The 16S rRNA genes of the new bog isolates and the original strains of R. acidophilus and Rhodoblastus sphagnicola, another acidophilic purple phototroph isolated from a Sphagnum peat bog in Russia, showed a 16S rRNA gene sequence similarity greater than or equal to 97%. All isolates were acidophilic and grew best photoheterotrophically on certain organic or fatty acids, or alcohols as carbon sources. Despite subtle physiological differences, all of the strains shared many characteristics. This indicates that R. acidophilus is a reasonably homogenous species and suggests that diversity of the acidophilic phototrophs may be low.