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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.
1

Pienarūgščių bakterijų paieška ir jų identifikavimas migruojančių didžiųjų ančių (Anas platyrhynchos) žarnyne naudojant dalinių 16S rRNR geno sekų analizę ir kultivavimu paremtus metodus / Identification of lactic acid bacteria in the migrant mallard ducks anas platyrhynchos intestinal tract by partial 16s rrna gene sequence analysis and using culture-based techniques

Varna, Klaidas 08 September 2009 (has links)
Pienarūgščių bakterijų paieška ir jų identifikavimas migruojančių didžiųjų ančių (Anas platyrhynchos) žarnyne naudojant dalinių 16S rRNR geno sekų analizę ir kultivavimu paremtus metodus Klaidas VARNA Vilniaus Universiteto Ekologijos Institutas, Hidrobiontų Ekologijos ir Fiziologijos Laboratorija bei Populiacinės Genetikos Laboratorija, Akademijos-2, Vilnius-21, 08412, Lietuva. Šiame tyrime pavasarinių ir rudeninių didžiųjų ančių (Anas platyrhynchos) migrantų iš Nemuno deltos virškinamojo trakto pieno rūgšties bakterijų įvairovė buvo ištirta naudojant molekulinius metodus (polimerazės grandininės reakcijos amplifikacija ir dalinių 16S rRNR geno sekų sekvenavimas) ir kultivavimu paremtus metodus. Migruojančių didžiųjų ančių (Anas platyrhynchos) pieno rūgšties bakterijų paieška buvo atlikta pirmą kartą. Rudeniniai didžiųjų ančių migrantai plonojo žarnyno sienelėse (1.2×107 iki 2.1×107 k.f.v./g) ir jų turinyje (nuo 3.4×107 iki 1.1×108 k.f.v./g) turi didesnį pieno rūgšties bakterijų skaičių nei pavasariniai migrantai (atitinkamai nuo 3.2×106 iki 4.8×106 k.f.v./g ir nuo 1.0×107 iki 2.2×107 k.f.v./g). Tiek rudeninių tiek ir pavasarinių didžiųjų ančių migrantų plonojo žarnyno sienelėse ir jų turinyje dominavo kokinės pieno rūgšties bakterijų formos (atitinkamai 65% ir 83.5% bei 81.4% ir 91.6%), o lazdelių buvo mažiau (atitinkamai 35% ir 16.5% bei 18.6% ir 8.4%). Manoma, kad minėtus skirtumus įtakoja keli veiksniai: ilgai trunkanti migracija, perėjimo periodas, skirtingas maistas ir... [toliau žr. visą tekstą] / Identification of lactic acid bacteria in the migrant mallard ducks Anas platyrhynchos intestinal tract by partial 16S rRNA gene sequence analysis and using culture-based techniques Klaidas VARNA Institute of Ecology of Vilnius University, Laboratory of Hydrobionts Ecology and Physiology, Laboratory of Population Genetics, Akademijos-2, Vilnius-21, 08412, Lithuania. In this study the lactic acid bacteria diversity of the intestinal tract content of the vernal and autumnal migrant mallard ducks (Anas platyrhynchos) from Nemuno delta has been investigated by molecular methods: polymerase chain reaction amplification and sequencing of partial 16S rRNA genes and using culture-based techniques. The investigation of the lactic acid bacteria of the migrant mallard ducks has been performed the first time. Autumnal migrant mallard ducks in the small intestine walls (from 1.2×107 until 2.1×107 c.f.u./g) and in their content (from 3.4×107 until 1.1×108 c.f.u./g have the greatest number of the lactic acid bacteria then vernal migrants (respectively from 3.2×106 until 4.8×106 c.f.u./g and from 1.0×107 until 2.2×107 c.f.u./g). In the small intestine walls and in their content of the autumnal and vernal migrant mallard ducks, dominated cocci-shaped lactic acid bacteria (respectively 65% and 83.5%, 81.4% and 91.6%), whereas rod-shaped was under (respectively 35% and 16.5%, 18.6% and 8.4%). Supposedly, that these defferences determine some factors: a long migration, period of incubate... [to full text]
2

Microbiome After Bariatric Surgery and Microbial Insights into Surgical Weight Loss

January 2016 (has links)
abstract: Obesity is a worldwide epidemic accompanied by multiple comorbidities. Bariatric surgery is currently the most efficient treatment for morbid obesity and its comorbidities. The etiology of obesity is unknown, although genetic, environmental, and most recently, microbiome elements have been recognized as contributors to this rising epidemic. The role of the gut microbiome in weight-loss or weight-gain warrants investigation, and bariatric surgery provides a good model to study influences of the microbiome on host metabolism. The underlying goals of my research were to analyze (i) the factors that change the microbiome after bariatric surgery, (ii) the effects of different types of bariatric surgeries on the gut microbiome and metabolism, (iii) the role of the microbiome on the success of bariatric surgery, and (iv) temporal and spatial changes of the microbiome after bariatric surgery. Roux-en-Y gastric bypass (RYGB) rearranges the gastrointestinal tract and reduces gastric acid secretions. Therefore, pH could be one of the factors that change microbiome after RYGB. Using mixed-cultures and co-cultures of species enriched after RYGB, I showed that as small as 0.5 units higher gut pH can aid in the survival of acid-sensitive microorganisms after RYGB and alter gut microbiome function towards the production of weight loss-associated metabolites. By comparing microbiome after two different bariatric surgeries, RYGB and laparoscopic adjustable gastric banding (LAGB), I revealed that gut microbiome structure and metabolism after RYGB are remarkably different than LAGB, and LAGB change microbiome minimally. Given the distinct RYGB alterations to the microbiome, I examined the contribution of the microbiome to weight loss. Analyses revealed that Fusobacterium might lessen the success of RYGB by producing putrescine, which may enhance weight-gain and could serve as biomarker for unsuccessful RYGB. Finally, I showed that RYGB alters the luminal and the mucosal microbiome. Changes in gut microbial metabolic products occur in the short-term and persist over the long-term. Overall, the work in this dissertation provides insight into how the gut microbiome structure and function is altered after bariatric surgery, and how these changes potentially affect the host metabolism. These findings will be helpful in subsequent development of microbiome-based therapeutics to treat obesity. / Dissertation/Thesis / Doctoral Dissertation Microbiology 2016
3

Caracterização da microbiota vaginal, intestinal e oral durante o período gestacional / Vaginal, gut and oral microbiota characterization during pregnancy

Sparvoli, Luiz Gustavo 27 May 2019 (has links)
A simbiose desenvolvida entre seres vivos e microrganismos desempenha um importante papel na relação saúde-doença do hospedeiro. Neste sentido, o corpo humano abriga uma grande e diversa comunidade de microrganismos, sendo as mucosas vaginal, intestinal e oral as principais superfícies mucosas do corpo feminino que abrigam as comunidades bacterianas de fundamental importância para a mulher. Estes microrganismos atuam no desenvolvimento e modulação do sistema imune, na manutenção e otimização de vias metabólicas e competem por sítios de colonização, prevenindo que microrganismos patogênicos estabeleçam colonização. A composição da microbiota feminina varia com a idade, pH, secreção hormonal, ciclo menstrual, uso de anticoncepcional e atividade sexual. O presente estudo buscou caracterizar a composição da microbiota do corpo feminino durante o período gestacional, comparando os achados entre gestantes e não gestantes saudáveis, através de técnicas de biologia molecular. Foram selecionadas 60 mulheres saudáveis para o estudo e coletadas amostras de secreção vaginal, fezes e swab oral de cada participante. O DNA das amostras foi extraído e submetido à sequenciamento do gene 16S rRNA e quantificado através da técnica de PCR em tempo real. Das participantes selecionadas, 42 eram gestantes e 18 eram mulheres não gestantes em idade reprodutiva. Observamos que a quantificação total de bactérias na vagina não apresentou diferenças entre gestantes e não gestantes. Houve aumento na abundância de Lactobacillus no sítio vaginal, bactérias produtoras de butirato na microbiota intestinal e Streptococcus na microbiota oral de mulheres grávidas quando comparadas com mulheres não gestantes. Além disso, observamos que a composição e a disposição dos gêneros encontrados sofrem uma modificação, tal como aumento de gêneros relacionados com a manutenção da homeostase no grupo de mulheres gestantes. O período gestacional influencia positivamente na composição da microbiota, garantindo assim a prevalência de gêneros bacterianos responsáveis pela manutenção das condições ideais para o desenvolvimento da gestação saudável. / The symbiosis developed between living organisms and microorganisms plays an important role in the health-disease relationship of the host. In this sense, the human body harbor a large and diverse community of microorganisms, the vaginal, intestinal and oral mucosa are the main mucosal surfaces of the female body that harbor bacterial communities of fundamental importance for women. These microorganisms act in the development and modulation of the immune system, in the maintenance and optimization of metabolic pathways and compete for colonization sites, preventing pathogenic microorganisms from establishing colonization. The composition of the female microbiota varies with age, pH, hormonal secretion, menstrual cycle, contraceptive use and sexual activity. The present study aimed to characterize the microbiota composition of the female body during the gestational period, comparing the findings between healthy and non - pregnant women through molecular biology techniques. Sixty healthy women were selected for the study and samples of vaginal secretion, stool and oral swab from each participant were collected. The DNA of the samples was extracted and submitted to the 16S rRNA gene sequencing and quantified by the real-time PCR technique. Were select, 42 were pregnant and 18 were non-pregnant women of reproductive age. We observed that the total quantification of bacteria in the vaginal samples did not present differences between pregnant and non-pregnant women. There was an increase in the abundance of Lactobacillus in the vaginal site, butyrate producing bacteria in the intestinal microbiota and Streptococcus in the oral microbiota of pregnant women when compared to nonpregnant women. In addition, we observed that the composition and arrangement of the genera found undergo a modification, such as an increase in genera related to the maintenance of homeostasis in the group of pregnant women. The pregnancy influences the composition of the microbiota, thus ensuring the prevalence of bacterial genera responsible for the maintenance of the ideal conditions for the development of healthy pregnancy.
4

Evaluation of microbiological and physico-chemical quality of water from aquifers in the North West Province, South Africa

Carstens, Alewyn Johannes January 2013 (has links)
Contamination of groundwater that is suitable for drinking is of growing concern as the water supply of South Africa is becomingincreasingly limited. This is especially the case in the North West province, with its semi – arid climate and variable rainfall patterns. The aim of the study was to evaluate the microbiological and physico – chemical qualities of groundwater obtained from selected DWA (Department of Water Affairs) monitoring boreholes in the Mooi River and Harts River catchment areas. Physico -chemical parameters included temperature, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), sulphate and nitrate concentrations. Physical parameters were measured using a calibrated submerge-able multimeter and chemical parameters using specialised kits and a spectrophotometer. Microbiological parameters included heterotrophic plate counts and total and faecal coliform enumeration. Membrane filtration and culture based methods were followed for enumeration of bacteria. During the identification procedures multiplex PCR for E. coli identification and 16S rRNA gene sequencing for identification of heterotrophic plate count bacteria and amoeba resistant bacteria were used. For antibiotic resistance, the Kirby- Bauer (1996) disk diffusion method was used. During the warm and wet season high electrical conductivity and salinity were observed in the Trimpark (65.3 mS/m; 325 ppm), School (125.1 mS/m; 644 ppm), Warrenton (166.9 mS/m; 867 ppm) and Ganspan (83.3 mS/m; 421 ppm) boreholes. Warrenton borehole had a high sulphate level (450 mg/l) as well. High chemical oxygen demand was observed in the Blaauwbank (62 mg/l) and Warrenton (98.5 mg/l) boreholes. In the dry and cold season similar observations were made for the various boreholes. Electrical conductivity and salinity levels remained high for the Trimpark (70.1 mS/m; 427.5 ppm), School (127 mS/m; 645 ppm), Warrenton (173.3 mS/m; 896.5 ppm) and Ganspan (88.1 mS/m; 444.5 ppm) boreholes. Nitrate levels for the Trimpark (14.1 mg/l) and School (137 mg/l), as well as sulphate levels for the Warrenton (325 mg/l) borehole were also high. Total coliforms, faecal streptococci and HPC bacteria were enumerated from water samples from all boreholes, except Blaauwbank where no faecal streptococci were enumerated. Faecal coliforms were enumerated from 5 of the possible 7 boreholes during a warm and wet season (Trimpark – 42 cfu/100ml; School – 2 cfu/100ml; Cemetery – 175 cfu/100ml; Warrenton – 3.84 x 10³ cfu/100ml; Ganspan – 1.9 x 10³ cfu/100ml). Indicator bacteria (FC, TC, HPC) exceeded target water quality ranges (TWQR) for drinking water in each case. During the cold and dry sampling season, faecal coliforms were enumerated mainly from the Trimpark (11 cfu/100ml) borehole. Total coliforms, faecal streptococci and HPC bacteria were enumerated from all the boreholes, except for Blaauwbank that contained no faecal streptococci or total coliforms. Enumerated indicator bacteria levels again exceeded TWQR for domestic use. Total coliform counts for the Pad dam borehole, however, complied with TWQR for domestic use. Identified E. coli were resistant to Erythromycin, Cephalothin and Amoxicillin and susceptible to Ciprofloxacin. Escherichia coli isolated from the Mooi River catchment shared the same antibiotic resistance phenotype. The most abundant HPC bacterial genus identified was Pseudomonas spp. (7 isolates). Opportunistic pathogens isolated included Pseudomonas aeruginosa, Acinetobacter, Aeromonas, Alcaligenes, Flavobacterium, Bacillus cereus and Mycobacterium spp. Varying degrees of antibiotic resistance were observed. Generally, the same pattern between the same genera were observed. All HPC isolates were resistant to Cephalothin and Amoxicillin and a lower degree Erythromycin and Streptomycin. The most abundant amoeba resistant bacteria was identified as Pseudomonas spp. Other isolates included Alcaligenes faecalis and Ochrobactrum sp. and Achromobacter sp. All of these are opportunistic pathogens, except for Achromobacter. Resistance to more antibiotics (Streptomycin, Chloramphenicol, Cephalothin, and Amoxicillin) was observed in ARBs compared to HPC (Cephalothin, Amoxicillin) from bulk water from the same borehole. The water of all the aquifers sampled is of very poor physico - chemical or microbiological quality or both. Water may be used for irrigation or livestock watering only in the case where these boreholes comply with TWQR for said purposes. Results obtained indicate that the groundwater is faecally contaminated. Amongst the bacteria, opportunistic pathogens displaying various degrees of antibiotic resistance were frequently isolated. These results indicate health risks if untreated groundwater is consumed. Therefore groundwater needs to be treated before distribution especially if the water is for human consumption. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.
5

Evaluation of microbiological and physico-chemical quality of water from aquifers in the North West Province, South Africa

Carstens, Alewyn Johannes January 2013 (has links)
Contamination of groundwater that is suitable for drinking is of growing concern as the water supply of South Africa is becomingincreasingly limited. This is especially the case in the North West province, with its semi – arid climate and variable rainfall patterns. The aim of the study was to evaluate the microbiological and physico – chemical qualities of groundwater obtained from selected DWA (Department of Water Affairs) monitoring boreholes in the Mooi River and Harts River catchment areas. Physico -chemical parameters included temperature, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), sulphate and nitrate concentrations. Physical parameters were measured using a calibrated submerge-able multimeter and chemical parameters using specialised kits and a spectrophotometer. Microbiological parameters included heterotrophic plate counts and total and faecal coliform enumeration. Membrane filtration and culture based methods were followed for enumeration of bacteria. During the identification procedures multiplex PCR for E. coli identification and 16S rRNA gene sequencing for identification of heterotrophic plate count bacteria and amoeba resistant bacteria were used. For antibiotic resistance, the Kirby- Bauer (1996) disk diffusion method was used. During the warm and wet season high electrical conductivity and salinity were observed in the Trimpark (65.3 mS/m; 325 ppm), School (125.1 mS/m; 644 ppm), Warrenton (166.9 mS/m; 867 ppm) and Ganspan (83.3 mS/m; 421 ppm) boreholes. Warrenton borehole had a high sulphate level (450 mg/l) as well. High chemical oxygen demand was observed in the Blaauwbank (62 mg/l) and Warrenton (98.5 mg/l) boreholes. In the dry and cold season similar observations were made for the various boreholes. Electrical conductivity and salinity levels remained high for the Trimpark (70.1 mS/m; 427.5 ppm), School (127 mS/m; 645 ppm), Warrenton (173.3 mS/m; 896.5 ppm) and Ganspan (88.1 mS/m; 444.5 ppm) boreholes. Nitrate levels for the Trimpark (14.1 mg/l) and School (137 mg/l), as well as sulphate levels for the Warrenton (325 mg/l) borehole were also high. Total coliforms, faecal streptococci and HPC bacteria were enumerated from water samples from all boreholes, except Blaauwbank where no faecal streptococci were enumerated. Faecal coliforms were enumerated from 5 of the possible 7 boreholes during a warm and wet season (Trimpark – 42 cfu/100ml; School – 2 cfu/100ml; Cemetery – 175 cfu/100ml; Warrenton – 3.84 x 10³ cfu/100ml; Ganspan – 1.9 x 10³ cfu/100ml). Indicator bacteria (FC, TC, HPC) exceeded target water quality ranges (TWQR) for drinking water in each case. During the cold and dry sampling season, faecal coliforms were enumerated mainly from the Trimpark (11 cfu/100ml) borehole. Total coliforms, faecal streptococci and HPC bacteria were enumerated from all the boreholes, except for Blaauwbank that contained no faecal streptococci or total coliforms. Enumerated indicator bacteria levels again exceeded TWQR for domestic use. Total coliform counts for the Pad dam borehole, however, complied with TWQR for domestic use. Identified E. coli were resistant to Erythromycin, Cephalothin and Amoxicillin and susceptible to Ciprofloxacin. Escherichia coli isolated from the Mooi River catchment shared the same antibiotic resistance phenotype. The most abundant HPC bacterial genus identified was Pseudomonas spp. (7 isolates). Opportunistic pathogens isolated included Pseudomonas aeruginosa, Acinetobacter, Aeromonas, Alcaligenes, Flavobacterium, Bacillus cereus and Mycobacterium spp. Varying degrees of antibiotic resistance were observed. Generally, the same pattern between the same genera were observed. All HPC isolates were resistant to Cephalothin and Amoxicillin and a lower degree Erythromycin and Streptomycin. The most abundant amoeba resistant bacteria was identified as Pseudomonas spp. Other isolates included Alcaligenes faecalis and Ochrobactrum sp. and Achromobacter sp. All of these are opportunistic pathogens, except for Achromobacter. Resistance to more antibiotics (Streptomycin, Chloramphenicol, Cephalothin, and Amoxicillin) was observed in ARBs compared to HPC (Cephalothin, Amoxicillin) from bulk water from the same borehole. The water of all the aquifers sampled is of very poor physico - chemical or microbiological quality or both. Water may be used for irrigation or livestock watering only in the case where these boreholes comply with TWQR for said purposes. Results obtained indicate that the groundwater is faecally contaminated. Amongst the bacteria, opportunistic pathogens displaying various degrees of antibiotic resistance were frequently isolated. These results indicate health risks if untreated groundwater is consumed. Therefore groundwater needs to be treated before distribution especially if the water is for human consumption. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.
6

Effects of Different Formulations of Glyphosate on Rumen Microbial Metabolism and Bacterial Community Composition in the Rumen Simulation Technique System

Brede, Melanie, Haange, Sven-Bastiaan, Riede, Susanne, Engelmann, Beatrice, Jehmlich, Nico, Rolle-Kampzczyk, Ulrike, Rohn, Karl, von Soosten, Dirk, von Bergen, Martin, Breves, Gerhard 06 June 2023 (has links)
The use of the herbicide glyphosate and its formulations on protein-rich feedstuff for cattle leads to a considerable intake of glyphosate into the rumen of the animals, where glyphosate may potentially impair the 5-enolpyruvylshikimate-3-phosphate pathway of the commensal microbiota, which could cause dysbiosis or proliferation of pathogenic microorganisms. Here, we evaluated the effects of pure glyphosate and the formulations Durano TF and Roundup® LB plus in different concentrations on the fermentation pattern, community composition and metabolic activity of the rumen microbiota using the Rumen Simulation Technique (RUSITEC). Application of the compounds in three concentrations (0.1mg/l, 1.0mg/l or 10mg/l, n=4 each) for 9days did not affect fermentation parameters such as pH, redox potential, NH3-N concentration and production of short-chain fatty acids compared to a control group. Microbial protein synthesis and the degradation of different feed fractions did not vary among the treatments. None of the used compounds or concentrations did affect the microbial diversity or abundance of microbial taxa. Metaproteomics revealed that the present metabolic pathways including the shikimate pathway were not affected by addition of glyphosate, Durano TF or Roundup® LB plus. In conclusion, neither pure glyphosate, nor its formulations Durano TF and Roundup® LB plus did affect the bacterial communities of the rumen.
7

Identificação de linhagens atípicas de Yersinia spp. por métodos moleculares / Identification of atypical Yersinia strains by molecular methods

Souza, Roberto Antonio de 25 May 2009 (has links)
O gênero Yersinia compreende 12 espécies. Y. enterocolitica, Y. pseudotuberculosis e Y. pestis são patógenos de vários animais, incluindo os humanos. Y. aldovae, Y. bercovieri, Y. frederiksenii, Y. intermedia, Y. kristensenii, Y. aleksiciae, Y. mollaretti e Y. rhodei são encontradas sobretudo no meio ambiente e alimentos e consideradas, usualmente, como bactérias oportunistas não-patogênicas e Y. ruckeri é um importante patógeno de peixes. Usualmente, as linhagens de Yersinia são classificadas em espécies de acordo com suas características bioquímicas. O Laboratório Nacional de Referência em Yersinia spp. outras que Y. pestis recebeu mais de 700 linhagens que foram identificadas bioquimicamente. Entretanto, sete linhagens de Yersinia não puderam ser identificadas pelos testes bioquímicos convencionais em nenhuma das espécies até o momento conhecidas e, por esse motivo, foram denominadas Yersinia atípicas. Os objetivos desse trabalho foram identificar as linhagens atípicas de Yersinia spp. em espécies por técnicas moleculares como Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), Eletroforese em Campo Pulsado (PFGE), sequenciamento do gene 16S rRNA e Multilocus Sequencing Typing (MLST) e definir dentre as metodologias empregadas a que mais contribui para a identificação precisa dessas linhagens. Foi estudado um total de 59 linhagens de Yersinia spp., sendo 52 linhagens representantes das diferentes espécies do gênero e sete as linhagens bioquimicamente atípicas de Yersinia. As técnicas de ERIC-PCR, sequenciamento do gene 16S rRNA e o MLST foram eficientes na identificação molecular do gênero Yersinia, uma vez que conseguiram reunir todas as espécies em ramos espécie-específicos, com exceção de algumas linhagens de Y. frederiksenii e Y. kristensenii. A técnica de PFGE, pelo contrário, não agrupou as linhagens estudadas em clusters espécie-específicos. Os dados de ERIC-PCR, sequenciamento do gene 16S rRNA e MLST, sugerem que as linhagens atípicas FCF 229 e FCF 231 pertençam à espécie Y. ruckeri. Os dados de ERIC-PCR e MLST sugerem que a linhagem atípica FCF 487 pertença à espécie Y. enterocolitica. Ademais, os dados de ERIC-PCR, sequenciamento do gene 16S rRNA e MLST sugerem que as linhagens atípicas FCF 216, FCF 465, FCF 457 e FCF 494 pertençam a espécie Y. massiliensis. Os resultados obtidos nesse trabalho fornecem dados importantes para a caracterização molecular de linhagens bioquimicamente atípicas de Yersinia e contribuem para uma melhor descrição do gênero quanto a sua diversidade e reforçam o MLST como uma técnica confiável e reprodutível a ser usada na identificação de bactérias pertencentes a esse gênero, sendo dentre as metodologias utilizadas nesse estudo a mais indicada para tipagem molecular de yersiniae. / The genus Yersinia comprises 12 species. Y. enterocolitica, Y. pseudotuberculosis and Y. pestis are pathogens of various animals, including humans. Y. aldovae, Y. bercovieri, Y. frederiksenii, Y. intermedia, Y. kristensenii, Y. aleksiciae, Y. mollaretti and Y. rohdei have been mostly found in the environment and food sources and are commonly considered to be opportunistic nonpathogenic bacteria and Y. ruckeri is an important fish pathogen. Usually, Yersinia strains are classified into species according to their biochemical characteristics. The Brazilian Reference Center on Yersinia spp. other than Y. pestis received more than 700 strains that were biochemically identified. However, seven strains that were typed as Yersinia could not be biochemically identified in any one of the currently known Yersinia species and for this reason they were named as atypical strains. The aims of this work were to identify into species the atypical Yersinia strains using molecular techniques as Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), Pulsed Field Gel Electrophoresis (PFGE), 16S rRNA gene sequencing and Multilocus Sequencing Typing (MLST) and to define which methodology better contribute to the identification of those strains. A total of 59 Yersinia spp. strains were studied, being 52 representative strains of the defined Yersinia species and seven atypical Yersinia strains. ERIC-PCR, 16S rRNA gene sequencing and MLST were efficient in molecular identifying the genera Yersinia once they grouped the strains into species-specific clusters, with exception of some Y. frederiksenii and Y. kristensenii strains. However, PFGE was not capable to cluster the defined Yersinia strains into species-specific clusters. The data obtained by ERIC-PCR, 16S rRNA gene sequencing and MLST suggest that the atypical strains FCF 229 and FCF 231 belong to Y. ruckeri species. The data obtained by ERIC-PCR and MLST suggest that FCF 487 belong to the Y. enterocolitica species. Additionally, ERIC-PCR, 16S rRNA gene sequencing and MLST suggest that the atypical strains FCF 216, FCF 465, FCF 457 and FCF 494 belong to the Y. massiliensis species. The results obtained provide important data for the molecular characterization of biochemically atypical strains and contribute for a better description of the genera regardless its diversity. Furthermore, the results reinforce MLST as a trustful and reproducible technique to be used in the identification of bacteria of this genus, being among the methodologies studied the most recommended one to molecular type yersiniae.
8

Obtenção e caracterização filogenética de consórcio de bactérias púrpuras não-sulforosas consumidoras de ácidos orgânicos visando a produção de hidrogênio em reator anaeróbio de batelada / Obtaintion and phylogenetic characterization of consortium of phototrophic purple non-sulfur bacteria for hydrogen production from organic acids in the anaerobic batch reactor

Lazaro, Carolina Zampol 17 April 2009 (has links)
O objetivo deste trabalho foi enriquecer consórcio microbiano a partir de mistura de lodo granular de digestor anaeróbio de fluxo ascendente sob condições fototróficas anoxigênicas. Por meio de técnica de biologia molecular foi possível identificar 17 unidades taxonômicas operacionais (UTO) no consórcio microbiano, dentre as quais seqüências similares a Rhodobacter, gênero amplamente citado nos estudos de produção de gás hidrogênio por bactérias fototróficas. Exames microscópicos do consórcio fototrófico indicaram predomínio de bacilos Gram-negativos. Ensaios sob condições fototróficas foram realizados com dois meios de cultivo (RCVB e FANG) e os seguintes substratos orgânicos: ácido acético, butírico, cítrico, lático e málico, empregados como fonte de carbono, tanto para o crescimento celular, como para a produção do gás hidrogênio. A relação C/N inicial foi 30/4 e posteriormente 15/2, com o objetivo de favorecer o crescimento celular e a produção do \'H IND.2\'. A concentração dos substratos foi determinada de forma com que essa relação se mantivesse a mesma. O crescimento celular e consumo dos ácidos orgânicos foram similares para os dois meios de cultivo empregados. Entretanto, a produção do gás hidrogênio foi maior nos ensaios com o meio FANG. Dentre os substratos utilizados o consumo dos ácidos cítrico e málico foram os maiores (~100%), para concentrações iniciais de 3,3 g/L e 2,6 g/L, respectivamente. O menor consumo 25% foi observado em meio RCVB e ácido acético (2,5 g/L). O crescimento da biomassa variou de 0,06 g/L a 1,1 g/L, enquanto que a velocidade máxima específica de crescimento variou de 0,4 a 0,2 g SSV/L.d entre os substratos utilizados. A menor e maior concentração de hidrogênio foram de 8,5 e 22 mmol \'H IND.2\'/L, para os reatores alimentados com ácido lático e málico em meio FANG, respectivamente. Pôde-se concluir que o consórcio fototrófico enriquecido foi capaz de utilizar os ácidos orgânicos para produção do gás hidrogênio. / The aim of this work was enrich a mixture of granular sludge of an up flow anaerobic sludge blanket (UASB) under anoxygenic phototrophic conditions. The techniques of molecular biology identified 17 operational taxonomic units (UTO) in the microbial consortium among the sequences analised, which were similar to Rhodobacter, genus widely cited in studies of hydrogen gas production by phototrophic bacteria. Microscopic examinations of the phototrophic consortium showed predominance of Gram-negative bacilli. Tests were conducted under phototrophic conditions with two culture media (RCVB and FANG) and the following organic substrates: acetic, butyric, citric, lactic and malic acids that were used as carbon source for both cell growth and for the hydrogen gas production. The carbon nitrogen ratio (C/N) in the preliminaries tests was 30/4 and then it was changed to15/2 in order to improve the cell growth and hydrogen production. The concentration of substrates was determined for remain the same carbon/nitrogen ratio among the substrates. The cell growth and consumption of organic acids were similar for the two culture media used. However, the production of hydrogen gas was higher in trials with the medium FANG. Among the substrates used, the consumption of malic and citric acids were the highest (~100%) for initial concentrations of 3.3 g/L and 2.6 g/L, respectively. The shortest consumption (25%) was observed for the cells that grew on acetic acid, 2.5 g/L in RCVB culture medium. The growth of the biomass varied from 0.06 g/L to 1.1 g/L, whereas the maximum specific growth rate ranged from 0.4 to 0.2 g VSS/L.d between the substrates used. The lowest and highest concentrations of hydrogen were 8.5 and 22 mmol \'H IND.2\'/L for the reactor fed with lactic acid and malic acid in FANG\'s medium, respectively. It was concluded that the phototrophic consortium was able to use those organic acids for the production of hydrogen gas.
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Obtenção e caracterização filogenética de consórcio de bactérias púrpuras não-sulforosas consumidoras de ácidos orgânicos visando a produção de hidrogênio em reator anaeróbio de batelada / Obtaintion and phylogenetic characterization of consortium of phototrophic purple non-sulfur bacteria for hydrogen production from organic acids in the anaerobic batch reactor

Carolina Zampol Lazaro 17 April 2009 (has links)
O objetivo deste trabalho foi enriquecer consórcio microbiano a partir de mistura de lodo granular de digestor anaeróbio de fluxo ascendente sob condições fototróficas anoxigênicas. Por meio de técnica de biologia molecular foi possível identificar 17 unidades taxonômicas operacionais (UTO) no consórcio microbiano, dentre as quais seqüências similares a Rhodobacter, gênero amplamente citado nos estudos de produção de gás hidrogênio por bactérias fototróficas. Exames microscópicos do consórcio fototrófico indicaram predomínio de bacilos Gram-negativos. Ensaios sob condições fototróficas foram realizados com dois meios de cultivo (RCVB e FANG) e os seguintes substratos orgânicos: ácido acético, butírico, cítrico, lático e málico, empregados como fonte de carbono, tanto para o crescimento celular, como para a produção do gás hidrogênio. A relação C/N inicial foi 30/4 e posteriormente 15/2, com o objetivo de favorecer o crescimento celular e a produção do \'H IND.2\'. A concentração dos substratos foi determinada de forma com que essa relação se mantivesse a mesma. O crescimento celular e consumo dos ácidos orgânicos foram similares para os dois meios de cultivo empregados. Entretanto, a produção do gás hidrogênio foi maior nos ensaios com o meio FANG. Dentre os substratos utilizados o consumo dos ácidos cítrico e málico foram os maiores (~100%), para concentrações iniciais de 3,3 g/L e 2,6 g/L, respectivamente. O menor consumo 25% foi observado em meio RCVB e ácido acético (2,5 g/L). O crescimento da biomassa variou de 0,06 g/L a 1,1 g/L, enquanto que a velocidade máxima específica de crescimento variou de 0,4 a 0,2 g SSV/L.d entre os substratos utilizados. A menor e maior concentração de hidrogênio foram de 8,5 e 22 mmol \'H IND.2\'/L, para os reatores alimentados com ácido lático e málico em meio FANG, respectivamente. Pôde-se concluir que o consórcio fototrófico enriquecido foi capaz de utilizar os ácidos orgânicos para produção do gás hidrogênio. / The aim of this work was enrich a mixture of granular sludge of an up flow anaerobic sludge blanket (UASB) under anoxygenic phototrophic conditions. The techniques of molecular biology identified 17 operational taxonomic units (UTO) in the microbial consortium among the sequences analised, which were similar to Rhodobacter, genus widely cited in studies of hydrogen gas production by phototrophic bacteria. Microscopic examinations of the phototrophic consortium showed predominance of Gram-negative bacilli. Tests were conducted under phototrophic conditions with two culture media (RCVB and FANG) and the following organic substrates: acetic, butyric, citric, lactic and malic acids that were used as carbon source for both cell growth and for the hydrogen gas production. The carbon nitrogen ratio (C/N) in the preliminaries tests was 30/4 and then it was changed to15/2 in order to improve the cell growth and hydrogen production. The concentration of substrates was determined for remain the same carbon/nitrogen ratio among the substrates. The cell growth and consumption of organic acids were similar for the two culture media used. However, the production of hydrogen gas was higher in trials with the medium FANG. Among the substrates used, the consumption of malic and citric acids were the highest (~100%) for initial concentrations of 3.3 g/L and 2.6 g/L, respectively. The shortest consumption (25%) was observed for the cells that grew on acetic acid, 2.5 g/L in RCVB culture medium. The growth of the biomass varied from 0.06 g/L to 1.1 g/L, whereas the maximum specific growth rate ranged from 0.4 to 0.2 g VSS/L.d between the substrates used. The lowest and highest concentrations of hydrogen were 8.5 and 22 mmol \'H IND.2\'/L for the reactor fed with lactic acid and malic acid in FANG\'s medium, respectively. It was concluded that the phototrophic consortium was able to use those organic acids for the production of hydrogen gas.
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Identificação de linhagens atípicas de Yersinia spp. por métodos moleculares / Identification of atypical Yersinia strains by molecular methods

Roberto Antonio de Souza 25 May 2009 (has links)
O gênero Yersinia compreende 12 espécies. Y. enterocolitica, Y. pseudotuberculosis e Y. pestis são patógenos de vários animais, incluindo os humanos. Y. aldovae, Y. bercovieri, Y. frederiksenii, Y. intermedia, Y. kristensenii, Y. aleksiciae, Y. mollaretti e Y. rhodei são encontradas sobretudo no meio ambiente e alimentos e consideradas, usualmente, como bactérias oportunistas não-patogênicas e Y. ruckeri é um importante patógeno de peixes. Usualmente, as linhagens de Yersinia são classificadas em espécies de acordo com suas características bioquímicas. O Laboratório Nacional de Referência em Yersinia spp. outras que Y. pestis recebeu mais de 700 linhagens que foram identificadas bioquimicamente. Entretanto, sete linhagens de Yersinia não puderam ser identificadas pelos testes bioquímicos convencionais em nenhuma das espécies até o momento conhecidas e, por esse motivo, foram denominadas Yersinia atípicas. Os objetivos desse trabalho foram identificar as linhagens atípicas de Yersinia spp. em espécies por técnicas moleculares como Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), Eletroforese em Campo Pulsado (PFGE), sequenciamento do gene 16S rRNA e Multilocus Sequencing Typing (MLST) e definir dentre as metodologias empregadas a que mais contribui para a identificação precisa dessas linhagens. Foi estudado um total de 59 linhagens de Yersinia spp., sendo 52 linhagens representantes das diferentes espécies do gênero e sete as linhagens bioquimicamente atípicas de Yersinia. As técnicas de ERIC-PCR, sequenciamento do gene 16S rRNA e o MLST foram eficientes na identificação molecular do gênero Yersinia, uma vez que conseguiram reunir todas as espécies em ramos espécie-específicos, com exceção de algumas linhagens de Y. frederiksenii e Y. kristensenii. A técnica de PFGE, pelo contrário, não agrupou as linhagens estudadas em clusters espécie-específicos. Os dados de ERIC-PCR, sequenciamento do gene 16S rRNA e MLST, sugerem que as linhagens atípicas FCF 229 e FCF 231 pertençam à espécie Y. ruckeri. Os dados de ERIC-PCR e MLST sugerem que a linhagem atípica FCF 487 pertença à espécie Y. enterocolitica. Ademais, os dados de ERIC-PCR, sequenciamento do gene 16S rRNA e MLST sugerem que as linhagens atípicas FCF 216, FCF 465, FCF 457 e FCF 494 pertençam a espécie Y. massiliensis. Os resultados obtidos nesse trabalho fornecem dados importantes para a caracterização molecular de linhagens bioquimicamente atípicas de Yersinia e contribuem para uma melhor descrição do gênero quanto a sua diversidade e reforçam o MLST como uma técnica confiável e reprodutível a ser usada na identificação de bactérias pertencentes a esse gênero, sendo dentre as metodologias utilizadas nesse estudo a mais indicada para tipagem molecular de yersiniae. / The genus Yersinia comprises 12 species. Y. enterocolitica, Y. pseudotuberculosis and Y. pestis are pathogens of various animals, including humans. Y. aldovae, Y. bercovieri, Y. frederiksenii, Y. intermedia, Y. kristensenii, Y. aleksiciae, Y. mollaretti and Y. rohdei have been mostly found in the environment and food sources and are commonly considered to be opportunistic nonpathogenic bacteria and Y. ruckeri is an important fish pathogen. Usually, Yersinia strains are classified into species according to their biochemical characteristics. The Brazilian Reference Center on Yersinia spp. other than Y. pestis received more than 700 strains that were biochemically identified. However, seven strains that were typed as Yersinia could not be biochemically identified in any one of the currently known Yersinia species and for this reason they were named as atypical strains. The aims of this work were to identify into species the atypical Yersinia strains using molecular techniques as Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), Pulsed Field Gel Electrophoresis (PFGE), 16S rRNA gene sequencing and Multilocus Sequencing Typing (MLST) and to define which methodology better contribute to the identification of those strains. A total of 59 Yersinia spp. strains were studied, being 52 representative strains of the defined Yersinia species and seven atypical Yersinia strains. ERIC-PCR, 16S rRNA gene sequencing and MLST were efficient in molecular identifying the genera Yersinia once they grouped the strains into species-specific clusters, with exception of some Y. frederiksenii and Y. kristensenii strains. However, PFGE was not capable to cluster the defined Yersinia strains into species-specific clusters. The data obtained by ERIC-PCR, 16S rRNA gene sequencing and MLST suggest that the atypical strains FCF 229 and FCF 231 belong to Y. ruckeri species. The data obtained by ERIC-PCR and MLST suggest that FCF 487 belong to the Y. enterocolitica species. Additionally, ERIC-PCR, 16S rRNA gene sequencing and MLST suggest that the atypical strains FCF 216, FCF 465, FCF 457 and FCF 494 belong to the Y. massiliensis species. The results obtained provide important data for the molecular characterization of biochemically atypical strains and contribute for a better description of the genera regardless its diversity. Furthermore, the results reinforce MLST as a trustful and reproducible technique to be used in the identification of bacteria of this genus, being among the methodologies studied the most recommended one to molecular type yersiniae.

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