S'avaluaren 58 soques de Pseudomonas fluorescens i Pantoea agglomerans per la seva eficàcia en el biocontrol de la malaltia causada per l'oomicet Phytophthora cactorum en maduixera i pel nematode formador de gal·les Meloidogyne javanica en el portaempelt GF-677.Es desenvolupà un mètode ex vivo d'inoculació de fulla amb l'objectiu de seleccionar soques bacterianes com a agents de control biològic de P. cactorum en maduixera. Tres soques de P. fluorescens es seleccionaren com a soques eficaces en el biocontrol del patogen en fulles i en la reducció de la malaltia en plantes de maduixera. La combinació de soques semblà millorar la consistència del biocontrol en comparació amb les soques aplicades individualment.Tres soques de P. fluorescens es seleccionaren per la seva eficàcia en la reducció de la infecció de M. javanica en portaempelts GF-677. La combinació d'aquestes soques no incrementà l'eficàcia del biocontrol, però semblà reduir la seva variabilitat. / 58 Pseudomonas fluorescens and Pantoea agglomerans strains were evaluated for their biocontrol efficacy against the oomycete Phytophthora cactorum in strawberry and the root-knot nematode Meloidogyne javanica in GF-677 rootstocks.An ex vivo detached leaf inoculation method was developed to select bacterial strains as biological control agents of P. cactorum in strawberry. Three P. fluorescens strains were selected as effective in biocontrol of the pathogens on leaves and in disease reduction in strawberry plants. Combination of strains improved biocontrol consistency compared to strains applied individually. Three P. fluorescens strains were selected for their efficacy in M. javanica infection reduction in GF-677 rootstocks. Combination of these strains did not increase biocontrol efficacy, but reduced its variability.

Το πρόβλημα της ρύπανσης του εδάφους και του υδροφόρου ορίζοντα έχει πάρει ανησυχητικές διαστάσεις τις τελευταίες δεκαετίες. Η βιομηχανική ανάπτυξη πέρα απο τις θετικές συνέπειες που έχει για την ζωή των ανθρώπων, έχει δυστυχώς επιφέρει προβλήματα ρύπανσης του υπεδάφους και του υδροφόρου ορίζοντα με επικίνδυνες οργανικές ενώσεις. Η αλόγιστη και ανεύθυνη διαχείριση και διάθεση των αποβλήτων έχει αρνητικές και συχνά μη αντιστρεπτές συνέπειες για το οικοσύστημα και την δημόσια υγεία. Ανάμεσα στις μεθόδους για την αντιμετώπιση του προβλήματος της ρύπανσης του εδάφους και των υπογείων υδάτων, οι βιολογικές μέθοδοι κερδίζουν ολοένα έδαφος λόγω του χαμηλού κόστους, της αποτελεσματικότητας και του ελάχιστου αριθμού παραπροϊόντων. Οι βιολογικές μέθοδοι αποσκοπούν στην αποκατάσταση των εδαφών με την χρήση γηγενών μικροοργανισμών του εδάφους. Η κινητική ανάπτυξης των μικροοργανισμών στο έδαφος διαφέρει σημαντικά από την κινητική ανάπτυξης όταν οι μικροοργανισμοί αιωρούνται σε καλά αναδευόμενα περιβάλλοντα. Η συγκεκριμένη εργασία έχει σαν στόχο να μελετηθεί η κινητική ανάπτυξης ενός γηγενούς βακτηριακού πληθυσμού, του Pseudomonas fluorescens κατά την βιοαποδόμηση της φαινόλης σε κατάλληλη πειραματική διάταξη, χρησιμοποιώντας ως πρότυπο πορώδες μέσο πυριτική άμμο (SiO2) η οποία αποτελεί ένα από τα βασικότερα συστατικά του εδάφους. Η φαινόλη είναι μία αρωματική ένωση η οποία χρησιμοποιείται συχνά στην βιομηχανία για την παρασκευή χρωμάτων, πλαστικών και φαρμάκων. Εξαιτίας της ευρείας χρήσης της, συναντάται συχνά στο έδαφος και τον υδροφόρο ορίζοντα. Για τον σκοπό αυτό έγιναν αρχικά πειράματα σε διαφορικές κλίνες άμμου με πηγή άνθρακα την γλυκόζη έτσι ώστε να αναπτυχθεί η κατάλληλη πειραματική διάταξη και διαδικασία για την περαιτέρω μελέτη της κινητικής ανάπτυξης του μικροοργανισμού Pseudomonas fluorescens. Στην συνέχεια μελετήθηκε η κινητική ανάπτυξης του μικροοργανισμού χρησιμοποιώντας ως πηγή άνθρακα την φαινόλη σε κλίνες άμμου. Παράλληλα έγιναν και πειράματα διαλείποντος έργου για την μελέτη της κινητικής ανάπτυξης του συγκεκριμένου μικροοργανισμού σε υγρές καλλιέργειες με θρεπτικό υπόστρωμα τόσο την γλυκόζη όσο και την φαινόλη. Σκοπός των πειραμάτων αυτών ήταν ο προσδιορισμός των κινητικών παραμέτρων. Τέλος αναπτύχθηκε κατάλληλο θεωρητικό μοντέλο για την προσομοίωση της κινητικής ανάπτυξης ενός βακτηριακού πληθυσμού στην μικροσκοπική κλίμακα. Απώτερος στόχος του θεωρητικού μοντέλου σε συνδυασμό με τα πειραματικά αποτελέσματα είναι να γίνει αποσαφήνιση των μηχανισμών αποδόμησης τοξικών ρύπων στην μικροσκοπική κλίμακα απο γηγενή βακτήρια και να αναπτυχθούν απλά κριτήρια για την πρόβλεψη και τον σχεδιασμό αποτελεσματικών μεθόδων αντιμετώπισης περιπτώσεων ρύπανσης του υπεδάφους και του υδροφόρου ορίζοντα. / The problem of soil and groundwater contamination has been increasing in the last few decades. Industrial growth is usually accompanied by pollution of groundwater with hazardous organic compounds. Irresponsible disposal of organic compounds into the soil has serious adverse consequences for the ecosystem and public health. Among methods that have been proposed for remediation of contaminated soils, biological methods using microorganisms which are indigenous in soil, are preferable because of their low cost, effectiveness and the low production of byproducts. Growth kinetics of microorganisms in soil differs significantly from growth kinetics of microorganisms suspended in a well-mixed stirred tank reactor. The aim of the present work was the experimental study of growth kinetics of a soilindigenous strain of the bacterium Pseudomonas fluorescens in sand packs (model soil) during the biodegradation of phenol. Phenol is an aromatic organic compound, which is widely used in industry, e.g. in paints, plastics, pharmaceuticals and many other products. Due to its extensive use, phenol is a common pollutant, especially in soil and groundwater. Experiments were initially conducted in sand packs, using glucose as a carbon source. The purpose of these experiments was the setup and test of the experimental procedure. Further experiments of growth kinetics in sand packs were conducted using phenol as a carbon source. In order to determine the growth kinetic parameters of Pseudomonas fluorescens for glucose and phenol biodegradation, batch experiments in liquid cultures were conducted. Finally, a hybrid simulator was developed for the theoretical investigation of growth kinetics of a bacterial population consisted a biofilm in microscale. The further aim of the theoretical simulator combined with the experimental results, was the elucidation of biodegradation mechanisms of toxic compounds by soil-indigenous bacteria in microscale, in order simple criteria for the prediction and remediation of polluted soils and groundwater to be developed.

Ecological processes have the potential to influence evolution through their effects on selection. This thesis explores the effects of two ecological factors - competition and ecological opportunity. Intraspecific (within-species) competition is often expected to drive adaptation and diversification by increasing selection for the use of novel resources, thereby alleviating the detrimental effects of competition. However, this is not always the expected outcome; theory suggests that intraspecific competition can also drive convergent evolution. On the other hand, interspecific (between-species) competition is usually expected to impede adaptation and diversification because competitor species occupy potential available niches, preventing the focal species from diversifying to do so. In this thesis, I review previous experimental studies exploring the effects of competition on adaptive diversification, and then directly test these effects using experimental evolution of the bacterium Pseudomonas fluorescens. I confirm that intraspecific competition drives adaptive diversification, while the effects of interspecific competition are varied. Strong interspecific competition impedes adaptation and diversification, while the presence of weak, non-diversifying interspecific competitors drives diversification through increased resource competition. The presence of ecological opportunity is essential for adaptation and diversification, and so variation in attributes of those opportunities is expected to have important effects on the dynamics of adaptive evolution. In another evolution experiment with P. fluorescens, I tested the effects of variation in ecological opportunity on adaptive evolution and found that the type and arrangement of ecological opportunities drives adaptation but, in this system, not diversification. I also show that ecological opportunity drives differences in the degree of parallel evolution at the phenotypic and genotypic level. Finally, I explore some unexpected genetic changes identified in one of these evolved populations - two synonymous mutations that conferred fitness benefits, and show that the observed fitness improvements are the result of increased gene expression. I have shown that ecological processes can play an important role in shaping the evolutionary trajectories taken by populations. Understanding the interactions between ecological and evolutionary processes is vital for our understanding of evolutionary dynamics as a whole, and the studies laid out in this thesis represent valuable contributions to this field of study.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Freie Univ., Diss.--Berlin, 2005. / Zusfassung in engl. Sprache.

Caenorhabditis elegans is a natural predator of the mushroom pathogen Pseudomonas fluorescens NZI7. The bacterial mechanisms for reducing predation by the nematode through the secretion of secondary metabolites have been described, but not yet fully explored. The behaviour of nematodes is influenced by the different factors produced by the pseudomonads. In this thesis we develop a range of assays to link the behaviour of C. elegans to these factors to identify their role in bacteria-nematode interactions. We show that these factors play two distinct roles: they may either repel nematodes, or harm them. This permits the classification of mutants of P. fl. NZI7 lacking these factors as either attractive, edible or both. Many studies of C. elegans behaviour have demonstrated that the nematode can distinguish between different food sources. Our results show two distinct types of response: chemotaxis drives the response to attractive or repellent stimuli, and nematodes also show a choice behaviour that is independent of chemotaxis. This choice behaviour is determined by bacterial edibility and requires nematodes to come into contact with the bacteria. This contact is the foundation of the bacterial dispersal by nematodes. By making use of the luminescence property of the available bacterial mutants, we demonstrate an intimate link between the behaviour of C. elegans and the success with which bacteria are disseminated: if nematodes are induced to regularly leave a bacterial colony, whether through their genotype or the low edibility of the food, then they will spread bacteria effectively. Throughout this thesis, we use computational simulations based on a hybrid cellular automaton model to represent the nematode-bacteria interactions. These simulations recreate the observed behaviour of the system, thus they help to confirm our hypotheses and establish the fundamental aspects of the interactions between the two species.

Submitted by Programa de Pós-graduação em Biotecnologia (mebiotec.ufba@gmail.com) on 2017-04-04T15:22:46Z No. of bitstreams: 1 DISSERTAÇÃO FINAL - CARLA SAMPAIO.pdf: 3521182 bytes, checksum: b57b50cebbb6edde7f67fab290614074 (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2017-07-06T13:12:51Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO FINAL - CARLA SAMPAIO.pdf: 3521182 bytes, checksum: b57b50cebbb6edde7f67fab290614074 (MD5) / Made available in DSpace on 2017-07-06T13:12:51Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO FINAL - CARLA SAMPAIO.pdf: 3521182 bytes, checksum: b57b50cebbb6edde7f67fab290614074 (MD5) / CAPES / Manguezais são ecossistemas costeiros, considerados berçários naturais para muitas espécies de animais. São ambientes que possuem uma acentuada influência das marés. Por se localizarem em regiões costeiras e próximos a indústrias petrolíferas, são alvos constantes de contaminação por petróleo e derivados e se faz necessário estudos sobre técnicas que minimizem os impactos ambientais ocasionados pela presença desses contaminantes. Este trabalho objetivou avaliar técnicas de biorremediação para recuperação ex situ de sedimento de manguezal, através da simulação de contaminação por óleo diesel. Utilizou-se a Rhizophora mangle L. e as linhagens bacterianas CCMICS105 Pseudomonas fluorescens e CCMICS108 Bacillus sp., produtoras de compostos bioativos e promotoras do crescimento de plantas. Os resultados evidenciam que houve redução nos percentuais de n-Alcanos e HPAs de cadeia leves presentes no sedimento, sobretudo nos tratamentos 1 e 2 em que houve a inoculação das bactérias. As bactérias isoladas dos propágulos do Controle 1 e do Tratamento 2 são endofíticas, exceto o isolado 10 que acredita-se ser a mesma bactéria presente no sedimento e na raiz. Todos os isolados do sedimento foram encontrados nas raízes do Tratamento 2, sendo que o isolado 2, que possui características semelhantes à bactéria CCMICS108, esteve em maior densidade. Os dados de MEV e do isolamento indicam que houve colonização das raízes no Tratamento 2 por bactérias semelhantes morfologicamente às linhagens CCMICS105 e CCMICS108. O que contribuiu para o aumento no número de propágulos germinados, para a redução, de modo geral, do espaço intercelular do córtex e da ramificação do sistema central, o que não foi constatado no Tratamento 3. Apesar de não haver diferença significativa nos pesos fresco e seco das plantas nos controles e tratamentos, o Tratamento 2 foi o que apresentou maior biomassa. A Rhizophora mangle L., neste trabalho, não foi eficaz na biodegradação de hidrocarbonetos, possivelmente devido a elevada concentração do óleo diesel (55μg.mL-1) utilizada. / Mangroves are coastal ecosystems, provide nursery habitat for many wildlife species. Are environments that have a marked influence of the tides. Since they are located in coastal areas and near oil industries, mangroves may be a target of contamination by oil and oil products and must be necessary studies of techniques that can minimize environmental impacts caused by the presence of these contaminants. This study aimed to evaluate ex situ bioremediation utilizing techniques simulating contamination by diesel in mangrove sediment. We used the red mangrove Rhizophora mangle L. and bacterial strains Pseudomonas fluorescens (CCMICS105) and Bacillus sp. (CCMICS108), bioactive compounds producing and plant growth promoting bacterias. The results show that there was a decrease in n-alkanes percentage and light chain of PAHs in the sediment, especially in treatments 1 and 2 in which there was inoculation of bacteria. The bacteria isolated from the seedlings from Control 1 and Treatment 2 are endophytic, except isolated 10 that we believe belongs from the sediment and roots. All sediment isolates were found in the roots from Treatment 2, and the isolated 2 shows similar characteristics to CCMICS108 and was higher in density (biomass). The SEM data and from the isolation point to root colonization in Treatment 2 by morphologically similar bacterias CCMICS105 and CCMICS108. Contributing to the increase in the number of seedlings germinated, to reduce, in general, the intercellular space of the cortex and the branch of the central system, which was not observed in Treatment 3. Although there is no significant difference in fresh and dry weights of plants in the control and treatments, the Treatment 2 showed the highest biomass. The Rhizophora mangle L., in this work was not effective to hydrocarbon biodegradating, possibly due to high concentration of diesel used (55μg.mL-1).

Submitted by Hiolanda Rêgo (hiolandarego@gmail.com) on 2018-02-05T13:28:04Z No. of bitstreams: 1 Dissertação_ICS_ Carla Jaqueline Silva Sampaio.pdf: 3630364 bytes, checksum: 96761afb3c1977087b3e9a1e2dae1c5f (MD5) / Made available in DSpace on 2018-02-05T13:28:05Z (GMT). No. of bitstreams: 1 Dissertação_ICS_ Carla Jaqueline Silva Sampaio.pdf: 3630364 bytes, checksum: 96761afb3c1977087b3e9a1e2dae1c5f (MD5) / Petrobrás; Capes / Manguezais são ecossistemas costeiros, considerados berçários naturais para muitas espécies de animais. São ambientes que possuem uma acentuada influência das marés. Por se localizarem em regiões costeiras e próximos a indústrias petrolíferas, são alvos constantes de contaminação por petróleo e derivados e se faz necessário estudos sobre técnicas que minimizem os impactos ambientais ocasionados pela presença desses contaminantes. Este trabalho objetivou avaliar técnicas de biorremediação para recuperação ex situ de sedimento de manguezal, através da simulação de contaminação por óleo diesel. Utilizou-se a Rhizophora mangle L. e as linhagens bacterianas CCMICS105 Pseudomonas fluorescens e CCMICS108 Bacillus sp., produtoras de compostos bioativos e promotoras do crescimento de plantas. Os resultados evidenciam que houve redução nos percentuais de n-Alcanos e HPAs de cadeia leves presentes no sedimento, sobretudo nos tratamentos 1 e 2 em que houve a inoculação das bactérias. As bactérias isoladas dos propágulos do Controle 1 e do Tratamento 2 são endofíticas, exceto o isolado 10 que acredita-se ser a mesma bactéria presente no sedimento e na raiz. Todos os isolados do sedimento foram encontrados nas raízes do Tratamento 2, sendo que o isolado 2, que possui características semelhantes à bactéria CCMICS108, esteve em maior densidade. Os dados de MEV e do isolamento indicam que houve colonização das raízes no Tratamento 2 por bactérias semelhantes morfologicamente às linhagens CCMICS105 e CCMICS108. O que contribuiu para o aumento no número de propágulos germinados, para a redução, de modo geral, do espaço intercelular do córtex e da ramificação do sistema central, o que não foi constatado no Tratamento 3. Apesar de não haver diferença significativa nos pesos fresco e seco das plantas nos controles e tratamentos, o Tratamento 2 foi o que apresentou maior biomassa. A Rhizophora mangle L., neste trabalho, não foi eficaz na biodegradação de hidrocarbonetos, possivelmente devido a elevada concentração do óleo diesel (55μg.mL-1) utilizada.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-03-27T13:36:10Z No. of bitstreams: 1 texto completo.pdf: 1000365 bytes, checksum: 3842d8127fe803978100ef7fd2e2c7b2 (MD5) / Made available in DSpace on 2017-03-27T13:36:10Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1000365 bytes, checksum: 3842d8127fe803978100ef7fd2e2c7b2 (MD5) Previous issue date: 2016-07-29 / A proteólise do leite causada principalmente por P. fluorescens, é um problema importante na indústria de laticínios por causa da deterioração do leite cru e pasteurizado refrigerado durante o armazenamento. O presente estudo descreve o isolamento, a caracterização de bacteriófagos para P. fluorescens (NCTC 10038) e o biocontrole de P. fluorescens no leite cru e pasteurizado armazenado a 4, 15 e 24 °C. Os bacteriófagos foram isolados de amostras de água residuária de vários setores de uma indústria de laticínio. Foram isolados seis bacteriófagos, dos quais três (UFV-SG, UFV-HD e UFV-HQ) foram testados contra algumas condições encontradas na indústria de alimentos e produtos antimicrobianos, pois, todos apresentaram mesmo perfil pormifórmico. Determinaram-se também os parâmetros cinéticos de crescimento destes bacteriófagos. Os bacteriófagos estudados atingiram concentrações em torno de 10 9 UFP ∙ mL -1 , apresentando uma taxa de absorção aproximada de 1,83 x 10 -9 mL.min -1 a cada infeção da célula bacteriana foram liberados aproximadamente 200 bacteriófagos por ciclo. Estes bacteriófagos foram sensíveis à luz UV, pasteurização lenta, álcool 70, álcool gel, ácido peracético; desincrustante ácido para inox e o detergente alcalino para lavagem CIP, mas foram resistentes a várias condições, tais como sanitizantes dicloroisocianurato de sódio, peróxido de hidrogênio, pasteurização rápida, sais e ácidos, mostrando potencial para utilização na indústria alimentar. Os resultados deste estudo sugerem que o bacteriófago é uma alternativa para o biocontrole de P.fluorescens no leite quando aplicado em concentrações elevadas e armazenado a baixas temperaturas. Foram identificados alguns detergentes e sanitizantes que podem ser utilizados na descontaminação de superfícies e equipamentos contaminados por bacteriófagos que afetem a produção na indústria de lacticínios. / The proteolysis of milk mainly caused by P. fluorescens, is a major problem in the dairy industry because of the deteriorating raw milk pasteurized and refrigerated during storage. The present study describes the isolation and characterization of bacteriophages for P. fluorescens (NCTC 10038) and P. fluorescens biocontrol in raw and pasteurized milk stored at 4, 15 and 24 ° C. Bacteriophages were isolated from wastewater samples from various sectors of the dairy industry. six bacteriophages were isolated, of which three (UFV-SG, UFV-HD and UFV-HQ) were tested against some conditions found in the food industry and antimicrobial products, because all had the same profile. It also determined the kinetic parameters of growth of these bacteriophages. Bacteriophage concentrations studied reached around 10 9 PFU∙mL -1 having an approximate rate of absorption of 1.83 x 10 -9 ml min -1 for each infection of bacterial cells were released approximately 200 phage per cycle. These bacteriophage were sensitive to UV light, pasteurization, alcohol 70, alcohol gel, peracetic acid; descaling stainless and acid to the alkaline CIP detergent for washing, but were resistant to various conditions, such as sodium dichloroisocyanurate of sanitizers, hydrogen peroxide, quick pasteurization, salts and acids, showing potential for use in the food industry. The results of this study suggest that the bacteriophage is an alternative for the biocontrol of P. fluorescens in milk when applied in high concentrations and stored at low temperatures. They identified some detergents and sanitizers which may be used to decontaminate surfaces contaminated with bacteriophages and equipment that affect the production in the dairy industry. / Sem lattes

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-11-08T17:50:12Z No. of bitstreams: 1 texto completo.pdf: 848123 bytes, checksum: 39ad4634d41468604f2afeb499a0ef04 (MD5) / Made available in DSpace on 2016-11-08T17:50:12Z (GMT). No. of bitstreams: 1 texto completo.pdf: 848123 bytes, checksum: 39ad4634d41468604f2afeb499a0ef04 (MD5) Previous issue date: 2005-07-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A adesão de Pseudomonas fluorescens ATCC 13525 foi avaliada pela microscopia de epifluorescência (EPF) e contagem padrão em placas (CPP) em superfícies usadas no processamento de alimentos nos tempos de contato 0, 2, 4, 6, 8 e 10 h. O aumento da adesão entre as superfícies, em razão do tempo, não foi acompanhado de forma similar pelas técnicas avaliadas. Por exemplo, no tempo quatro horas, as superfícies que apresentaram maiores logaritmos de UFC.cm-2 e que não apresentaram diferença significativa na adesão pelo teste de Scott-Knott (P > 0,05) foram poliuretano rugoso dupla face, silicone revestido com tecido, poli (cloreto de vinila) revestimento grosso com tecido, granito e mármore pela técnica EPF. Já pela técnica CPP, no mesmo tempo de contato, os maiores logaritmos de UFC.cm-2 foram para superfícies de silicone revestido com tecido, poliuretano rugoso dupla face, granito e poliuretano revestido com tecido. As superfícies de mármore, granito, poli (cloreto de vinila) revestimento grosso com tecido, poliuretano rugoso dupla face e silicone revestido com tecido diferiram das demais no grau de adesão, expresso em UFC.cm-2 (P < 0,05) nos tempos 4, 6, 8 e 10 horas, quando avaliadas pela técnica da epifluorescência, e de 2 e 10 horas, quando avaliadas pela contagem padrão em placas. Numa outra forma de avaliação, constatou-se também a diferença entre as 12 técnicas com relação ao agrupamento das superfícies de acordo com a similaridade de adesão. Assim, as superfícies que apresentaram maior percentagem de similaridade e maior média geral com relação à adesão pela técnica EPF foram mármore, granito e poliuretano rugoso dupla face. No caso da CPP, este mesmo fato foi constatado com as superfícies de poliuretano rugoso dupla face, silicone revestido com tecido e granito. As superfícies apresentaram características de microtopografias muito diferentes quando observadas por microscopia eletrônica de varredura, o que pode justificar as diferenças entre os graus de adesão observados. As técnicas possuem comportamentos diferentes para cada tempo de contato. Constatou-se que a CPP, além de fornecer resultados menores do que a EPF, também permite a detecção de valores de adesão mais baixos, sendo considerada uma técnica mais sensível. Porém, a CPP fornece resultados mais demorados do que a EPF. Para que haja detecção pela EPF, a quantidade de células aderidas aos cupons deve estar com contagens médias de uma célula por campo, no mínimo. A EPF permite verificar a morfologia das células, bem como, a distribuição destas bactérias aderidas às diferentes superfícies avaliadas. É recomendável utilizar a EPF para a quantificação de bactérias sésseis, principalmente quando as contagens sejam menores ou iguais a 4,1 x 105 UFC.cm-2. Este experimento mostrou que Pseudomonas fluorescens ATCC 13525 aderiu nas superfícies avaliadas. Entretanto, não há como sugerir a superfície mais recomendada para a utilização em processamento de alimentos devido a suas aplicações específicas. Os resultados mostram a importância de práticas higiênicas corretas na indústria de alimentos. / The adhesion of Pseudomonas fluorescens ATCC 13525 was evaluated by the epifluorescence microscopy (EPF) and the plate count method (CPP) to surfaces used in food processing at 0, 2, 4, 6, 8 and 10 h contact times. The adhesion increase among the surfaces, in relation to time, was not followed in a similar way by the evaluated techniques. For example, in four hours, the surfaces which showed greater CFU.cm-2 logarithms and that did not show a significant difference in the adhesion by the Scott- Knott test (P > 0.05) were the double-faced rugous polyurethane, silicon coated with cloth, PVC thick coated with cloth, granite and marble by the EPF technique. Whereas by the CPP technique, in the same contact time, the greater CFU.cm-2 logarithms were for the silicone coated with cloth, double-faced rugous polyurethane, granite and polyurethane coated with cloth surfaces. The marble, granite, PVC thick coated with cloth, double faced rugous polyurethane and silicone coated with cloth surfaces differed form the others in the adhesion degree expressed in CFU.cm-2 (P > 0.05) in the 4, 6, 8 and 10 h times, when evaluated by the epifluorescence technique and, at 2 and 10 h, when evaluated by the plate count method. In another kind of evaluation, the differences between the techniques concerning the surfaces cluster according to the adhesion similarity were also observed. Thus, the surfaces, which showed a greater similarity percentage and a greater general average concerning the adhesion by the 14 EPF technique, were marble, granite and double-faced rugous polyurethane. In the CPP, this same fact was observed with the double-faced rugous polyurethane, silicone coated with cloth and granite surfaces. The surfaces showed very different microtopography characteristics when observed by the scanning electron microscopy, which can justify the differences between the observed adhesion degrees. The techniques have different behaviors for each contact time. It was observed that CPP, besides providing results lower than the EPF, also allowed the detection of lower adhesion values, being considered a more sensitive technique. However, the CPP provides longer results than the EPF. So that there is a detection by EPF, the quantity of adhered cells to the coupons must be with, at least, an average count of one cell per field. The EPF allows the cell morphology assay as well as the distribution of these bacteria adhered to the different evaluated surfaces. It is recommendable to use the EPF technique for the sessile bacteria quantifying, especially when the count is lower or equal to 4,1 x 105 CFU.cm-2. This study showed that the Pseudomonas fluorescens ATCC 13525 adhered to the evaluated surfaces. However, there is no way to suggest the most recommendable surface for the use in the food processing due to their specific application. The results show the importance of the correct hygienic practices in the food industry.