München, Techn. University, Diss., 2002.

Köln, Universiẗat, Diss., 2002.

La conservación de alimentos por fermentación natural es ampliamente practicada por diversas comunidades nativas. El “masato” es producto de este proceso y constituye parte importante de la alimentación de los pobladores de la amazonía peruana. La masa de yuca, mandioca o cassava (Manihot esculenta, Crantz) utilizada en la preparación de esta bebida tradicional, constituye el substrato principal para el establecimiento de una microflora mixta ambiental, incluyendo las bacterias lácticas como responsables de la fermentación maloláctica, láctica y otras propiedades de interés industrial. La búsqueda de nuevas cepas nativas de bacterias lácticas productoras de sustancias antimicrobianas, adaptadas a las condiciones ambientales y materias primas regionales, es sumamente importante, para mejorar la calidad sensorial y sanitaria del “masato”. Para detectar cepas lácticas con propiedades antimicrobianas, se procesaron 11 muestras de “masato” procedentes de Pucallpa – Ucayali, las cuales fueron sembradas en agar Man Rogosa Sharpe (MRS) pH 6.5 e incubadas a 30° C por 72 horas en condiciones de microaerofilia. La caracterización morfológica, cultural, bioquímica y la actividad antimicrobiana se realizaron según Kandler Weiss (1986) y Tagg McGiven, (1971) respectivamente. De un total de 81 cepas de Lactobacillus aisladas, se identificaron 33 (41%) de Lactobacillus plantarum, 13 (16%) de Lactobacillus alimentarius, 12 (15%) de Lactobacillus acidophilus, 9 (11%) de Lactobacillus casei y en menores porcentajes Lactobacillus brevis, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus amylophilus y Lactobacillus coryniformis. Se encontró además, 64 (78.9%) de Lactobacillus heterofermentativos y 17 (21.1%) de Lactobacillus homofermentativos. En todas las muestras de “masato” evaluadas, predominó Lactobacillus plantarum, seguido de Lactobacillus acidophilus y Lactobacillus alimentarius. De 8 cepas lácticas productoras evaluadas, Lactobacillus plantarum M4 fue la única cepa productora de una sustancia antimicrobiana que no es ácido orgánico ni agua oxigenada. Se demostró además, que la sustancia antimicrobiana neutralizada a pH 6,5 posee un reducido espectro antimicrobiano y es estable en un amplio rango de temperatura y pH. Asimismo, las cepas de Lactobacillus muestran un alto nivel de tolerancia a concentraciones de etanol agregadas al medio de cultivo, siendo mas del 80% de cepas aisladas tolerantes a 10% de etanol, mientras que 6% tolera concentraciones de hasta 12% v/v de etanol. Se proponen las cepas Lactobacillus plantarum 4M0.2, Lactobacillus plantarum M9.5, Lactobacillus acidophilus M2.9, Lactobacillus alimentarius 5M1.2 como una selección de cepas de interés biotecnológico, así como a Lactobacillus plantarum M4, cepa del estudio con mayor espectro antimicrobiano tolerante hasta una concentración de 8% v/v de etanol en el medio de cultivo. / The food preservation by natural fermentation is practiced by diverse native communities. The "masato" is product of this process and constitutes important part of the feeding of the population of peruvian amazonia. The mass of yucca, mandioca or cassava (Manihot esculenta, Crantz) used in the preparation of this traditional drink, constitutes the main substrate for the establishment of an environmental mixed microflora, including the lactic acid bacteria which are responsible for the malolactic and lactic fermentation and other properties of industrial interest. The search of new native strains of antimicrobial substances producing lactic bacteria, adapted to the environmental conditions and regional raw materials, is extremely important, to improve the sensorial and sanitary quality of the "masato". In order to detect lactic strains with antimicrobial properties, 11 samples of "masato" coming from Pucallpa - Ucayali were processed, which were seeded in agar Man Rogosa Sharpe (MRS) pH 6,5 and incubated to 30° C by 72 hours in microaerophilic conditions. The morphologic, cultural, biochemical characterization and the antimicrobial activity were made according to Kandler Weiss (1986) and Tagg McGiven, (1971) respectively. Of a total of 81 isolated strains of Lactobacillus, 33 (41%) of Lactobacillus were identified like Lactobacillus plantarum, 13 (16%) like Lactobacillus alimentarius, 12 (15%) like Lactobacillus acidophilus, 9 (11%) like Lactobacillus casei and in smaller percentage like Lactobacillus brevis, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus amylophilus and Lactobacillus coryniformis. In addition, 64 (78.9%) and 17 (21.1%) of Lactobacillus were detected homofermenters and heterofermenters respectively. In all the evaluated samples of "masato", predominated Lactobacillus plantarum, followed of Lactobacillus acidophilus and Lactobacillus alimentarius. Of 8 evaluated antimicrobial substance producing lactic acid bacteria strains, Lactobacillus plantarum M4 was the only producing strain of a antimicrobial substance that is not acid organic nor oxygenated water. In addition, it was shown that the neutralized antimicrobial substance to pH 6.5 has a reduced antimicrobial spectrum and is stable in a wide range of temperature and pH. Also, the strains of Lactobacillus showed a high level of tolerance to concentrations of ethanol added to culture means, being but of 80% of tolerant isolated strains to 10% of ethanol, whereas 6% tolerated concentrations of up to 12% v/v of ethanol. We propose to Lactobacillus plantarum 4M0.2, Lactobacillus plantarum M9.5, Lactobacillus acidophilus M2.9, Lactobacillus alimentarius 5M1.2 like a selection of strains of biotechnological interest, as well as to Lactobacillus plantarum M4, strain of the study with greater antimicrobial spectrum and tolerance until 8% v/v concentration of ethanol added in culture mean. / Tesis

No description available.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2009. / Includes bibliographical references. Also available on the World Wide Web.

Köln, Universiẗat, Diss., 2001.

Orientador: Marco Antonio Alvarenga / Banca: Alexandre Secorun Borges / Banca: Eliane Melo Brolazo / Resumo: Na égua o ambiente uterino saudável não apresenta microflora, diferente da vagina onde se sabe existir uma flora vaginal rica em microrganismos não patogênicos. Muitas bactérias da flora vaginal normal podem ser deslocadas para o interior do útero, podendo ser esta a causa principal de endometrites em éguas doadoras de embriões. A presença de Lactobacillus spp é considerada importante na flora vaginal de mulheres e tem sido pouco investigada em éguas. O presente trabalho tem como objetivo estudar a flora vaginal de éguas, doadoras de embriões, determinar os principais microrganismos presentes, relacionar os achados microbiológicos vaginais e uterinos, assim como determinar a prevalência de Lactobacillus. No experimento 1 foram utilizadas 77 éguas doadoras de embrião, 33 foram coletadas amostras vaginais e uterinas e 77 apenas vaginais. O experimento 2 contou com dois grupos (36 éguas e 10 mulheres) de swabs vaginais sendo um para cultivo e isolamento de Lactobacillus e outro para extração do DNA e PCR. As bactérias predominantes na vagina foram: Streptococcus zooepidemicus (42%), Escherichia coli (25%), Streptococcus alfa hemolítico (15%) Candida (6%), Enterobacter spp (3%), Bacillus spp (3%), Streptococcus beta hemolítico (3%) e Pseudomonas (3%).. Das 33 amostras coletadas do útero de éguas somente 39% (n=12) não apresentaram crescimento bacteriano ou fúngico. Tendo sido Streptococcus zooepidemicus o mais frequentemente encontrado (26%), seguido de Escherichia coli (15%), Candida spp (9%), Streptococcus alfa hemolítico (6%) e Enterobacter (3%). Os microrganismos isolados da vagina e que estavam concomitantemente presentes no útero de éguas foram: Streptococcus zooepidemicus (21%), Escherichia coli (12%), Candida spp (9%) e Streptococcus alfa hemolítico (6%). Em 83,3% houve concordância entre as amostras negativas na vagina e no útero (p <0,05). Em 73,7% ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Different from the vagina, were a rich microflora is present, the uterine environment is considered free of microorganisms. One possibility for the installation of endometritis in mares is the ascendent contamination from the vagina.The presence of Lactobacillus on vaginal flora is considered important in woman however there is few information on mares. The present experiment aimed to study the vaginal microflora of embryo donnor mares, to correlate the vaginal and uterine finds and also to determine the prevalence of Lactobacillus on vaginal envirioment. On experiment 1 a total of 77 mares were used and vaginal samples collected from 33 of these mares both vaginal and uterine samples were collected. On experiment 2 vaginal swabs from 36 mares and 10 women were collected for culture and isolation of Lactobacillus, DNA extration and PCR. The predominate bacteria isolated from the vagina were: Streptococcus zooepidemicus (42%), Escherichia coli (25%), Streptococcus alfa hemolítico (15%) Candida (6%), Enterobacter spp (3%), Bacillus spp (3%), Streptococcus beta hemolítico (3%) e Pseudomonas (3%). From 33 samples collected from the uterus only 39% (n= 12) did not show any microorganism on culture. Streptococcus zooepidemicus was the most frequent isolated microorganism (26%), followed by Escherichia coli (15%), Candida spp (9%), Streptococcus alfa hemolítico (6%) e Enterobacter (3%). When evaluated the microorganisms isolated from both vaginal and uterine samples Streptococcus zooepidemicus (21%), Escherichia coli (12%), Candida spp (9%) e Streptococcus alfa hemolytic (6%) were the most frequent isolated bacteria. The agreement between swabs taken from both uterus and vagina was 83.3% (p <0,05) for negative cultures and 73,7% for positive cultures (p <0,05). From 35 samples collected on group I Lactobacillus spp was isolated in only two (5,7%) eight (20%) samples showed positive ... (Complete abstract click electronic access below) / Mestre

That Lactobacillus arabinosus 17-5, ATCC 8014, can supply its own requirement for the amino acid, lysine, is demonstrated by the fact that the organism is capable of growth in media devoid of lysine. Since the final biosynthetic step in lysine formation in all bacteria studied to date involves the decarboxylation of meso-dlaminopimelic acid (DAP) to produce lysine, it was of interest to determine whether an enzyme catalyzing such a reaction (DAP decarboxylase) is present in L. arabinosus.

This study is concerned with the metabolism of L-asparagine in Lactobacillus plantarum (ATCC 8014). Theprimary area of investigation is the preliminary characterization of a previously unreported L-asparaginase enzyme in L. plantarum. This L-asparaginase was determined to be an inducible enzyme with variations in its activity level according to the L-asparagine level in the growth medium. L-Glutaminase could not be induced in this organism by L-glutamine, nor would L-glutamine induce the asparaginase activity. These and other studies with amino acid analogs demonstrated the high specificity of both induction and enzymic activity of the asparaginase. Various physical properties of the enzyme were studied. The enzyme was found to be inhibited by adenosine triphosphate (ATP). This inhibition appears to be cooperative in nature and of the type exhibited by allosteric enzymes. These studies should be confirmed on a highly purified enzyme as these preliminary experiments were performed using a crude cell-free extract.

A procura por suplementos alimentares cresce a cada ano, pois o seu uso contínuo promove a melhora e manutenção da qualidade de vida do hospedeiro. Sustentado neste princípio, a ingestão de produtos probióticos, principalmente leites fermentados, passa a ser uma alternativa neste segmento do mercado. Os probióticos são suplementos alimentares que contem microrganismos vivos que trazem benefícios à saúde do consumidor pela manutenção e melhora do balanço microbiano do trato gastrintestinal. Existem vários gêneros de microrganismos que apresentam propriedades probióticas, destacando-se o gênero Lactobacillus; que exercem várias funções benéficas ao hospedeiro como a diminuição dos níveis de colesterol sangüíneo, efeito anticarcinogênico, adesão ao epitélio intestinal, melhora do sistema imune e a exclusão competitiva, conhecida também como efeito barreira. Dentro deste contexto, o presente trabalho teve como objetivo avaliar o efeito de inibição exercido por cinco cepas de Lactobacillus isoladas de fezes humanas: denominadas L. plantrum (Lac-01), L. plantarum (Lac-02), L. fermentum (Lac-03), L. fermentum (Lac-04) e L. fermentum (Lac-05) sobre o crescimento de E. coli O157:H7, Listeria spp., P. aeruginosa ATCC 27853, Salmonella typhi e Shigella spp , por meio da técnica de co-cultura. Os resultados revelaram que as cepas Lac-01, Lac-02 e Lac-03 foram capazes de inibir, em diferentes níveis, o crescimento das cepas patogênicas avaliadas, sendo este efeito mais acentuado para S. typhi e Shigella spp. Observou-se ainda que a cepa Lac-04 não apresentou efeito de inibição sobre E. coli O157:H7 e P. aeruginosa, ao passo que a cepa Lac-05 inibiu o crescimento de P. aeruginosa, S. typhi e Shigella spp., sendo incapaz de inibir E. coli O157:H7 e Listeria spp, nas condições estudadas. Posteriormente ao se verificar a produção de substâncias antimicrobianas por meio do método \"spot-test\", observou-se o efeito positivo de inibição exercida pelas cepas de Lactobacillus sobre o crescimento dos respectivos patógenos. Verificou-se também, por meio de testes enzimáticos específicos, que as substâncias antimicrobianas produzidas pelas cepas de Lactobacillus não foram sensíveis às enzimas utilizadas, não podendo afirmar, desta forma, que estas substâncias são bacteriocinas. Os testes de co-agregação demonstraram que as cepas Lac-04 e Lac-05 exerceram melhor efeito sobre os patógenos, quando comparadas com as cepas Lac-01 e Lac-02. A cepa Lac-03 não exerceu efeito de coagregação com nenhum dos patógenos avaliados. Os testes de autoagregação revelaram que as cepas Lac-01, Lac-02, Lac-04 e Lac-05 exerceram efeito de autoagregação acentuado. Observou-se ainda que nenhum dos patógenos estudados foi capaz de autoagregar. / The probiotics are special food that contain live microorganisms that promote beneficits to consumer health through maintenance and improvement of microbial balance of gut tract. There are many microorganisms species used in probiotics products, standing out Lactobacillus species that produce many beneficies to consumer like decrease of blood cholesterol level, anti-carcinogenic effect, adhrence to intestinal epithelium, immune system stimulation and the competitive exclusion, also known as barrier effect. In this regard, the present work aimed to evaluate the inhibition effect exerted by five Lactobacillus strains, isolated from humam faeces: denominate, L. plantarum Lac-01, L. plantarum Lac-02, L. fermentum Lac-03, L. fermentum Lac-04 e L. fermentum Lac-05 on the gowth of E. coli O157:H7, Listeria spp., Pseudomonas aeruginosa ATCC 27853, Salmonella typhi and Shigella spp., by means of coculture technique. The results showed that the strains Lac-01, Lac-02 and Lac-03, were able to inhibit, at different levels, the growth of pathogenic strains, and this effect was more accentuated on S. typhi and Shigella spp. It was also observed that the strain Lac-04 did not present inhibition effect on E. coli O157:H7 and P. aeruginosa ATCC 27853, and the Lac-05 inhibited the growth of P. aeruginosa, S. tyhpi and Shigella spp., and showed no effect on E. coli O157:H7 and Listeria spp. Afterwards, the production of antimicrobial substance was verified by means of \"spot-test\" method, showing the positive inhibition effect exerted by all Lactobacillus strains on the growth of the respective pathogens. By means of specific enzymatic test, the antimicrobial substances produced by lactobacillus strains were not sensible to the action of enzymes proteinase-K, papain and pepsin, but this is not enough to affirm that this substances are bacteriocins. The coaggregation test demonstrated that the strains Lac-04 and Lac-05 exerted better effect on the pathogens, when compared to strains Lac-01 and Lac-02. The strain Lac-03 did not coaggregate with any pathogenic strains. The autoaggregation test showed that the strain Lac-01, Lac-02, Lac-04 and Lac-05 exerted accentuated auto-aggregation effect. The studied pathogen was not able to autoaggregate.