In this study agriculturally important Pseudomonas spp. which may solubilize phosphate and Azotobacter chroococcum which can fix atmospheric nitrogen were grown on waste beer with 4 different concentrations and conditions for best growth were determined. Having potential of use as biofertilizers, they were put in the carrier material peat and survivals of them were observed for 3 months at three different temperatures. Biofertilizer can be defined as a substance which contains living microorganisms which, when applied to seed, plant surface, or soil, colonizes the rhizosphere or the interior of the plant and promotes growth by replacing soil nutrients or making nutrients more available or increasing plant access to nutrients. In order to benefit from the biofertilizers, viable and active microorganisms in high numbers must be present which requires high quality inoculants. The carrier substrate is a critical part of the product formulation and must be capable of supporting high numbers of the intended microbe(s). It was found that Pseudomonas spp. can solubilize phosphate. Furthermore, conditions for best growth for both bacteria were determined as 30 % of waste beer. Peat was found as an appropriate carrier due to preservation of viable cells for 3 months at 0 &ordm / C, 20 &ordm / C and 30 &ordm / C. However, peat couldn&rsquo / t support high numbers of Pseudomonas spp. at 30 &ordm / C.

Submitted by Alice Araujo (alice.caraujo@ufpe.br) on 2018-06-08T22:40:47Z No. of bitstreams: 1 DISSERTAÇÃO Jéssica Simões de Andrade.pdf: 3973394 bytes, checksum: 6b8ddd0c03c475c4a9a6eeab4afe7faa (MD5) / Made available in DSpace on 2018-06-08T22:40:47Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO Jéssica Simões de Andrade.pdf: 3973394 bytes, checksum: 6b8ddd0c03c475c4a9a6eeab4afe7faa (MD5) Previous issue date: 2016-07-28 / CAPES / Os danos causados pela corrosão atingem custos extremamente altos e estão associados à substituição de estruturas e equipamentos corroídos; custos da produção interrompida ou reduzida; diminuição da vida útil dos equipamentos e medidas necessárias para evitar ou prevenir o problema. A corrosão ocorre devido às interações físico-químicas e microbiológicas entre o material e o meio a que se encontra exposto. Dentre os principais meios corrosivos, a água do mar destaca-se por ser um meio bastante complexo constituído de solução de sais, matéria orgânica viva, gases dissolvidos e matéria orgânica em decomposição. Quando a corrosão do material ocorre mediante a participação de micro-organismos, recebe a denominação de biocorrosão ou Corrosão Microbiologicamente Induzida (CMI). O alumínio é um dos metais não-ferrosos mais abundantes da crosta terrestre, o que favorece o seu uso em grande escala. Apesar de apresentar boa propriedade de resistência à corrosão, a adição de elementos de liga, utilizada para aumentar sua resistência mecânica, confere menor eficiência à esta propriedade. No presente trabalho foram avaliados os efeitos da biocorrosão na liga de alumínio 5052 causada por Bactérias Redutoras de Sulfato (BRS) e Pseudomonas spp. em água do mar estéril. Corpos de prova previamente lixados #1200, medidos, desengordurados, pesados e esterilizados foram imersos em recipientes de vidro contendo quatro meios distintos, água do mar da Região do Porto do Recife estéril; água do mar estéril com adição de Bactérias Redutoras de Sulfato (BRS); água do mar estéril com Pseudomonas spp. e água do mar estéril contendo BRS e Pseudomonas spp. Foram realizadas análises físico-químicas da água de entrada para caracterização de sua composição. O crescimento dos biofilmes formados sobre a superfície do material metálico foi avaliado através de análises periódicas de quantificação microbiológica e Microscopia Eletrônica de Varredura (MEV) ao longo de 48 dias de imersão. O processo corrosivo envolvido, bem como a CMI, foram monitorados através de ensaios gravimétricos de perda massa para determinação da taxa de corrosão e ensaios eletroquímicos de Potencial de Circuito Aberto (PCA) e Polarização Linear. A caracterização das superfícies foi realizada através de microscopia óptica e MEV. Os resultados demostraram que a ação microbiológica ocasionou forte influência no processo de deterioração da liga de alumínio 5052. Valores de taxa de corrosão superiores foram observados pelos corpos de prova contendo Pseudomonas spp. isoladamente e taxas de corrosão mais baixas foram obtidas para o sistema contendo BRS. A análise dos biofilmes por MEV permitiu identificar bactérias isoladas e agregadas a EPS. Morfologia de corrosão localizada foi identificada para todos os sistemas estudados. Os resultados de potencial de circuito aberto mostraram valores de potencial iniciais mais negativos para os meios contendo BRS (isolada e em consórcio), sugerindo maior agressividade do meio para essas condições investigadas. Os ensaios de polarização evidenciaram que em tempos mais longos, os biofilmes formados podem promover um aumento na resistência à polarização, o que foi evidenciado pela redução da corrente anódica para o tempo de 15 dias. / Damage caused by corrosion reach extremely high costs and are associated with the replacement of corroded structures and equipment; costs of interrupted or reduced production; decrease the useful life of equipment and necessary measures to avoid or prevent the problem. Corrosion occurs due to physical, chemical and microbiological interactions between the material and the medium to which it is exposed. Among the major corrosive media, seawater stands out to be a very complex medium consisting of a salt solution, a living organic material, dissolved gases and decaying organic matter. When corrosion of the material occurs through the participation of micro-organisms, receives biocorrosion denomination or Microbiologically Induced Corrosion (MIC). Aluminium is one of the non-ferrous metals most abundant of the crust, which favors its use on a large scale. Despite showing good corrosion resistance property, the addition of alloying elements used to increase its mechanical strength, gives lower efficiency to this property. In the present study the effects of biocorrosion in 5052 aluminum alloy caused by sulfate-reducing bacteria (SRB) and Pseudomonas spp. in water sterile was evaluated Specimens previously polished #1200, measured, degreased, weighed and sterilized were immersed in glass containers with four different means of seawater the Port of Recife barren region; water sterile sea with addition of Sulfate Reducing Bacteria (SRB); water sterile sea with Pseudomonas spp .; and sterile water containing SRB in associated with Pseudomonas spp. Physico-chemical analysis of water intake were performed to characterize their composition. The growth of biofilms formed on the surface of the metal material was evaluated through periodic analysis of microbial quantification and Scanning Electron Microscopy (SEM) over 48 days of immersion. The corrosion process involved, as well as the MIC were monitored by gravimetric weight loss assays for determining the rate of corrosion and electrochemical tests Open Circuit Potential (OCP) and Linear Polarization. The characterization of the surfaces was performed under Optic microscopy and SEM. The results showed that the microbiological action caused strong influence in the process of deterioration of 5052 aluminum alloy. Higher corrosion rate values were observed for specimens containing Pseudomonas spp. isolated and lower corrosion rates were obtained for the system containing SRB. The analysis of biofilms by SEM identified bacteria isolated and aggregated EPS. Localized corrosion morphology was identified for all systems studied. The open circuit potential results showed more negative initial potential values for the containing media SRB (isolated and in a consortium), suggesting more aggressive the medium for these conditions investigated. Polarization tests revealed that for longer times, the formed biofilms may promote an increase in polarization resistance, which was evidenced by reduced anode current time for 15 days.

L'objectif de cette thèse est de contribuer à faire progresser les connaissances sur les interactions bénéfiques entre les plantes et les microorganismes en évaluant la contribution des systèmes de sécrétion de type III (SST3). Une synthèse des connaissances disponibles relatives aux SST3 chez les Pseudomonas non pathogènes, saprotrophes ou mutualistes, présentée chapitre I, montre que les SST3 ne sont pas cantonnés aux interactions parasites ou pathogènes avec les plantes. Dans l'étude expérimentale présentée chapitre II, nous avons utilisé différents génotypes de Medicago truncatula Gaertn. cv. Jemalong capables (Myc+) ou non (Myc-) d'établir une symbiose mycorhizienne. Ce travail nous a permis de montrer que les Pseudomonas spp. fluorescents possédant un SST3 (SST3+) sont préférentiellement associés aux racines mycorhizées des génotypes Myc+ de M. truncatula (J5 et TRV48) plutôt qu'aux racines du mutant Myc- (TRV25) et au sol nu. Ainsi, la plante seule n'est pas à l'origine de la présence accrue des Pseudomonas SST3+. La colonisation de la racine par les champignons mycorhizogènes à arbuscules (CMA), le développement du mycélium intraradiculaire et/ou la formation associée d'arbuscules, sont également déterminants. Dans l'étude présentée chapitre III, nous avons comparé les effets de la souche modèle promotrice de mycorhization (MHB) P. fluorescens C7R12 (SST3+) et de son mutant C7SM7 (SST3-), sur la mycorhization et la croissance de M. truncatula dans un sol non stérile. Ce travail a permis de montrer que le SST3 de C7R12 contribue à l'effet MHB de la bactérie. La promotion de la colonisation de la racine de M. truncatula par les CMA indigènes induite par le SST3 de C7R12 s'est traduite par une amélioration de la croissance de la plante. En revanche, l'inactivation du SST3 chez C7SM7 a eu un impact délétère sur la colonisation de la racine de M. truncatula par les CMA du sol étudié et sur la croissance de la plante. L'observation d'effets quantitatifs opposés entre C7R12 et C7SM7, nous a conduits à nous interroger sur l'existence d'un effet différentiel de l'inoculation de ces bactéries sur la structure et la diversité des communautés des microorganismes associés. Dans une étude présentée chapitre IV, le suivi dynamique en parallèle de la structure des communautés totales bactériennes (B-RISA) et fongiques (F-RISA) et de la colonisation de la racine par les CMA a été réalisée. Aucun effet de l'inoculation n'a été observé sur la structure des communautés fongiques de la rhizosphère ou des racines. En revanche, la structure des communautés bactériennes a varié selon que les plantes aient été inoculées ou non et selon la souche inoculée. Néanmoins, ces différences ont été observées plusieurs semaines après les effets de l'inoculation de C7R12 ou de C7SM7 sur la colonisation de la racine par les CMA. Ce décalage dans le temps, suggère que les différences observées dans la structure des communautés bactériennes pourraient être une conséquence plutôt qu'une cause des variations observées sur la mycorhization de M. truncatula. Nos résultats n'ont pas permis de mettre en évidence d'effets de l'inoculation sur la diversité des populations des bactéries fixatrices d'azote présentes dans les nodosités de M. truncatula. L'analyse des séquences de la grande sous-unité de l'ADN ribosomique (LSU rDNA) amplifiées à partir d'ADN extrait des racines, a montré pour les plantes inoculées et non inoculées, que les populations de CMA étaient majoritairement apparentées à Glomus intraradices. Un groupe d'isolats spécifiquement associé aux racines inoculées avec C7R12 et apparenté à G. claroideum a été décrit. Le groupe spécifique pourrait être associé à l'amélioration de la mycorhization observée dans les racines inoculées avec C7R12. Néanmoins, compte tenu de sa faible représentation numérique (8%), il semble probable que l'inoculation de C7R12 ait aussi un effet quantitatif sur la colonisation de la racine de M. truncatula par les CMA. etc

L'objectif de cette thèse est de contribuer à faire progresser les connaissances sur les interactions bénéfiques entre les plantes et les microorganismes en évaluant la contribution des systèmes de sécrétion de type III (SST3). Une synthèse des connaissances disponibles relatives aux SST3 chez les Pseudomonas non pathogènes, saprotrophes ou mutualistes, présentée chapitre I, montre que les SST3 ne sont pas cantonnés aux interactions parasites ou pathogènes avec les plantes. Dans l’étude expérimentale présentée chapitre II, nous avons utilisé différents génotypes de Medicago truncatula Gaertn. cv. Jemalong capables (Myc+) ou non (Myc-) d’établir une symbiose mycorhizienne. Ce travail nous a permis de montrer que les Pseudomonas spp. fluorescents possédant un SST3 (SST3+) sont préférentiellement associés aux racines mycorhizées des génotypes Myc+ de M. truncatula (J5 et TRV48) plutôt qu’aux racines du mutant Myc- (TRV25) et au sol nu. Ainsi, la plante seule n’est pas à l’origine de la présence accrue des Pseudomonas SST3+. La colonisation de la racine par les champignons mycorhizogènes à arbuscules (CMA), le développement du mycélium intraradiculaire et/ou la formation associée d’arbuscules, sont également déterminants. Dans l’étude présentée chapitre III, nous avons comparé les effets de la souche modèle promotrice de mycorhization (MHB) P. fluorescens C7R12 (SST3+) et de son mutant C7SM7 (SST3-), sur la mycorhization et la croissance de M. truncatula dans un sol non stérile. Ce travail a permis de montrer que le SST3 de C7R12 contribue à l’effet MHB de la bactérie. La promotion de la colonisation de la racine de M. truncatula par les CMA indigènes induite par le SST3 de C7R12 s’est traduite par une amélioration de la croissance de la plante. En revanche, l’inactivation du SST3 chez C7SM7 a eu un impact délétère sur la colonisation de la racine de M. truncatula par les CMA du sol étudié et sur la croissance de la plante. L’observation d’effets quantitatifs opposés entre C7R12 et C7SM7, nous a conduits à nous interroger sur l’existence d’un effet différentiel de l’inoculation de ces bactéries sur la structure et la diversité des communautés des microorganismes associés. Dans une étude présentée chapitre IV, le suivi dynamique en parallèle de la structure des communautés totales bactériennes (B-RISA) et fongiques (F-RISA) et de la colonisation de la racine par les CMA a été réalisée. Aucun effet de l’inoculation n’a été observé sur la structure des communautés fongiques de la rhizosphère ou des racines. En revanche, la structure des communautés bactériennes a varié selon que les plantes aient été inoculées ou non et selon la souche inoculée. Néanmoins, ces différences ont été observées plusieurs semaines après les effets de l’inoculation de C7R12 ou de C7SM7 sur la colonisation de la racine par les CMA. Ce décalage dans le temps, suggère que les différences observées dans la structure des communautés bactériennes pourraient être une conséquence plutôt qu’une cause des variations observées sur la mycorhization de M. truncatula. Nos résultats n’ont pas permis de mettre en évidence d’effets de l’inoculation sur la diversité des populations des bactéries fixatrices d’azote présentes dans les nodosités de M. truncatula. L’analyse des séquences de la grande sous-unité de l’ADN ribosomique (LSU rDNA) amplifiées à partir d’ADN extrait des racines, a montré pour les plantes inoculées et non inoculées, que les populations de CMA étaient majoritairement apparentées à Glomus intraradices. Un groupe d’isolats spécifiquement associé aux racines inoculées avec C7R12 et apparenté à G. claroideum a été décrit. Le groupe spécifique pourrait être associé à l’amélioration de la mycorhization observée dans les racines inoculées avec C7R12. Néanmoins, compte tenu de sa faible représentation numérique (8%), il semble probable que l’inoculation de C7R12 ait aussi un effet quantitatif sur la colonisation de la racine de M. truncatula par les CMA. etc / No abstract

Diazotrophic microbes reside in soybean nodules; however, other non-nitrogen fixing bacteria are a part of the interior nodule microbiome. Results from a previous greenhouse study show that a novel species of Pseudomonas associates with soybean nodules as a plant-growth promoting rhizobacteria (PGPR). This study observes the soybean growth promoting potential of Pseudomonas spp. in a field setting. Additionally, this study observed differences in soybean growth promotion based on amending the plant with isolated strains or a mixed culture of the species' strains. Two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were either amended with isolated strains of the novel Pseudomonas spp. (referred to as PAMW1 and BUMW2 in this study), a mix of the two strains, or an uninoculated control. The study recorded measurements to observe growth, yield, and nitrogen fixation differences. The study uses two-way factorial ANOVAs and non-parametric, multivariate analyses to determine differences in growth promotion among samples. Soybean amended with PAMW1 has greater shoot mass, biomass, and height than other treatments. Through nonmetric multidimensional scaling (NMS), samples amended with a mixed culture or PAMW1 may be different regarding growth promotion relative to the non-amended samples. Univariate results support the hypothesis that the novel Pseudomonas spp. benefit soybean in a field setting. However, it is inconclusive whether a mixed culture amendment of multiple strains alters the overall growth promotion of soybean compared to samples amended with isolated strains. / Master of Science / Soil hosts a relatively abundant and diverse community of microorganisms. Moreover, the area of soil that interacts closely with plant roots and their associated exudates, called the rhizosphere, has a significantly greater microbial abundance than surrounding bulk soil. Interactions between microbes and the plant often promote plant growth because of secondary metabolites produced by these beneficial microbes. One particular bacterial species, belonging to the Pseudomonas genus, was discovered and extracted from the soybean nodule interior. Nitrogen-fixing bacteria predominantly reside in the soybean nodule, yet this microorganism cannot fix nitrogen. Although trace amounts of non-nitrogen-fixing bacteria reside in the soybean nodule, this novel species has a relatively high abundance. This study determines the benefits of this species in the soybean nodule. Following positive results in a greenhouse study, this field experiment observes variance in soybean growth and productivity based on their received bacterial amendment. For this study, two soybean cultivars were either amended with an isolated strain of this species, a mix of the two strains, or left uninoculated to serve as a control. Numerous recorded measurements serve as indices of soybean growth and productivity. The results suggest that this novel Pseudomonas species benefits the plant by significantly improving biomass. With further research, this species can potentially serve as an environmentally sensitive and sustainable alternative to fertilizers through its ability to promote soybean growth.

Nitrogen-fixing bacteria in soybean nodules convert atmospheric nitrogen to plant-available forms in exchange for carbon from the plant, but other non-nitrogen-fixing bacteria also reside in nodules, and their role in the nodule is not well understood. This study was conducted to determine the effect of three non-nitrogen-fixing Pseudomonas spp. strains isolated from nodules on soybean, and we hypothesized these strains benefit soybean. A greenhouse study in which two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were treated with three fluorescent Pseudomonas spp. strains (referred to in this study as Bullseye, Pancake, and Starfish) and an uninoculated control. Soybeans were harvested at two time points: the R2/R3 growth stage and the R6 growth stage. Following each harvest, measures of growth, yield, and nitrogen fixation were taken, and data were analyzed using two non-parametric, multivariate analyses: multiple response permutation procedure (MRPP) and permutational multivariate analysis of variance (PERMANOVA). Both analyses showed soybeans of both cultivars treated with Pancake differed from controls following the first harvest but not the second. When analyzed individually, most metrics for growth, yield, and nitrogen fixation following the first harvest were not significantly different between Pancake and control treatments, but Pancake treatment means were still generally higher than controls. If metrics are considered collectively in conjunction with the results of the multivariate analyses, the results show Pancake generally increased soybean growth and nitrogen fixation. These findings support the hypothesis that non-nitrogen-fixing bacteria from nodules benefit plants, and such bacteria have the potential to serve as biofertilizers. / Master of Science in Life Sciences / Soybeans are one of the most commonly grown crops in the world, and nitrogen-fixing bacteria colonize the roots of soybeans and initiate the formation of spherical nodules attached to the roots. Inside the nodules, these bacteria convert atmospheric nitrogen to plant-available forms in exchange for sugar from the plant, and such bacteria reduce the need to add nitrogen fertilizer to agricultural fields. Other non-nitrogen-fixing bacteria also reside in nodules, but their role in the nodule is not well understood. If these bacteria benefit soybeans, they have the potential to serve as biofertilizers (microbial inoculants that promote plant growth). This study was conducted to determine whether non-nitrogen-fixing bacteria isolated from nodules benefit soybean. A greenhouse study in which two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were grown in soil and were either left uninoculated or were inoculated with one of three strains of bacteria from the genus, Pseudomonas (referred to in this study as Bullseye, Pancake, and Starfish). Following harvest, measures of growth, yield, and nitrogen fixation were taken, and data showed the bacteria generally benefited the soybean plants. Although, these results showed the bacteria benefitted the plants, field trials and further testing in the greenhouse should be conducted before using these bacteria as commercial biofertilizers. Additionally, the effects of other non-nitrogen-fixing nodule bacteria on soybeans should also be tested to identify other beneficial strains, and the cost of production should be compared to the potential gains of using such bacteria before they are developed into biofertilizers.