京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20891号 / 理博第4343号 / 新制||理||1623(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)講師 市川 正敏, 教授 山本 潤, 教授 前野 悦輝 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

No / The effectiveness of any ultraviolet germicidal irradiation (UVGI) system is governed by the passage of airborne microorganisms through the UV field. This paper describes a new method for evaluating the performance of UVGI devices using computational fluid dynamic (CFD) simulations. A microorganism inactivation equation is combined with a scalar transport equation to describe the concentration of airborne microorganisms in the presence of a UV field. The solution of this equation, in conjunction with the momentum and turbulent energy equations, allows the effect of both the airflow and the UV field on the microorganism distribution to be examined. Solutions are shown for the airflow and microorganism concentration through a bench scale flow apparatus, at five different UV intensities. The results from the CFD model are validated against the experimental data, obtained from the flow apparatus, for aerosolised Pseudomonas aeruginosa microorganisms. Good comparisons are seen, giving confidence in the application of the technique to other situations.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第24679号 / 農博第2562号 / 新制||農||1100(附属図書館) / 学位論文||R5||N5460(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 澤山 茂樹, 教授 吉田 天士, 准教授 中川 聡 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Yes / In this study, anti-corrosion concrete for sewage system was developed with nano TiO2 (NT) and reactive powder concrete (RPC). The corrosion resistances of NT modified RPC (NTMRPC) in high concentration enhanced sewage were investigated from the perspectives of biological, physical and chemical corrosion resistances, respectively. In addition, mechanical properties of NTMRPC after sewage corrosion were also studied. Research results indicated that NT can endow RPC with antimicrobial property through their microorganism biodegradation properties. The inhibition and elimination rates of NTMRPC to its surface microorganisms were 37.35% and 80.93%, respectively. After sewage corrosion, the surface roughness, mass loss and deterioration depth of RPC were decreased by 62.57%, 15.48% and 18.44% due to the NT inclusion, respectively. In addition, the pH values of RPC in the deterioration depth ranges of 0-3 mm and 3-6 mm were increased by 11.45% and 23.62%, respectively. NT can restrain the strength deterioration of RPC in high concentration enhanced sewage. This may be due to the improved sewage biological anti-corrosion performances of RPC by inhibiting/eliminating the microorganisms on the surface of RPC as well as the enhanced sewage physical/chemical anti-corrosion performances of RPC by improving the compactness of RPC. / The authors thank the funding provided by the National Science Foundation of China 513 (51978127 and 51908103), and National Key Research and Development Program of China 514 (2018YFC070560 and 2017YFC0703410).

In terrestrial ecosystems, microorganisms are the dominant drivers of virtually all ecosystem processes, particularly cycling of carbon (C), nitrogen (N), and phosphorus (P). These microbial functions are critical for promoting ecosystem services that support human well-being, such as provisioning of clean drinking water, nitrogen retention, and carbon storage. In forests of the Appalachian region of the eastern US, these ecosystem services are threatened by multiple anthropogenic influences, including present and past land use activities (e.g., logging, conversion to agriculture) and climate change (e.g., intensifying droughts). However, despite the central importance of microbial communities in promoting ecosystem functions, impacts of land management and climate change on soil microorganisms remain poorly understood in the region. This dissertation seeks to address the following questions: 1) How does a new forest management practice, Rhododendron understory removal, influence the ecosystem functions of soil microbial communities? 2) Do historical land management activities have long-term legacy effects on the structure and ecosystem functions of soil microbial communities? And 3) Does historical land use influence responses of soil microbial communities to intensifying drought? In chapter 2, I show that experimental Rhododendron understory removal increased soil C and N availability, thereby promoting increased total microbial biomass. This increased microbial biomass resulted in elevated production of microbial extracellular enzymes, which increased rates of C and N cycling in soils following Rhododendron removal. In chapter 3, I examined soils across several historically disturbed and adjacent undisturbed reference forests and show that historical management activities, e.g., logging, conversion to agriculture, have long-term effects on soil microbial communities 4-8 decades after management activities occurred. These effects included increased bacterial diversity, increased relative abundance of r-selected bacterial taxa, and increased abundance of arbuscular mycorrhizal fungi. In chapter 4, I show that key soil biogeochemical processes, i.e., C mineralization, N mineralization, and nitrification, exhibit generally higher rates in historically disturbed forests relative to adjacent reference forests. Further, I attributed these changes in ecosystem process rates to changes in key aspects of microbial communities, including microbial biomass, extracellular enzyme activities, and bacterial r- vs K-selection. In chapter 5, I conducted a drought-rewetting experiment and show wide-ranging effects of experimental drought on soil microbial communities, including altered diversity, community composition, and shifts in the relative abundances of several specific taxa. Further, drought responses were particularly evident in soils from historically disturbed forests, indicating influences of land management on responses of soil communities to climate change. Finally, in chapter 6, I show that the experimental drought also influenced several ecosystem-scale properties of soils, including increased soil N pools and increased respiratory C loss. Overall, my dissertation reveals wide-ranging effects of anthropogenic activities on soil microorganisms and shows that microbial communities will influence forest responses to global change at the ecosystem scale. / Doctor of Philosophy / Forest ecosystems of the southern Appalachian region provide numerous services that support human well-being, including provisioning of clean drinking water and the retention of nutrients and carbon (C). These ecosystem services are dependent on several processes that occur in soil, including the C and nitrogen (N) cycles. These cycles, in turn, are carried out primarily by microorganisms (bacteria and fungi) that live in soil. The ecosystem services provided by these forests are being threatened in the Appalachian region by a variety of land use activities such as logging and conversion of forests to agriculture and are also being threatened by climate change. However, despite the critical role of microorganisms in supporting ecosystem services, effects of land use activities and climate change on soil microorganisms are largely unknown in the Appalachian region. The goal of this dissertation is to answer the following questions: 1) How does Rhododendron understory removal, a new land management practice, influence soil microbial communities? 2) What are the long-term effects of historical land use activities, such as logging and conversion to agriculture, on soil microbial communities? And 3) In what ways will intensifying droughts influence soil microorganisms in Appalachian forests? I used a variety of approaches to answer these questions, including experiments and observational approaches. In chapter 2, I show that experimental Rhododendron understory removal increased the overall size of microbial communities (i.e., more microbial biomass) due to greater availability of soil resources (i.e., C and N). These larger microbial communities produced more enzymes involved in C and N metabolism, thereby increasing rates of C and N cycling in soils. In chapter 3, I surveyed soils from several forests that were disturbed by humans ~40-80 years previously (i.e., logged, converted to agriculture) and showed that these historical human activities have many long-term effects on soil bacteria and fungi. Specifically, in historically disturbed soils, I observed higher diversity of bacteria, higher abundance of rapidly growing (i.e., r-selected) bacteria and higher abundance of some groups of fungi that associate with plant roots and aid in acquiring nutrients for plants (i.e., mycorrhizal fungi). In chapter 4, I show that these historically disturbed soils also had altered rates of C and N cycling and that these altered cycling rates were associated with changes in several properties of microbial communities, including microbial enzymes, microbial biomass, and growth rates of bacteria (i.e., r-selection). In chapter 5, I conducted an experimental drought in these soils and show that drought has wide-ranging effects on many aspects of microbial communities, including effects on diversity, species composition, and abundances of many specific microbial taxonomic groups. Further, responses of microbial communities were larger in soils from historically disturbed forests, showing that past management will influence microbial responses to future climate change. In chapter 6, I show that many aspects of the soil ecosystems as a whole were also impacted by the experimental drought. In particular, soils exposed to drought released more CO2 over the course of the experiment and had higher N concentrations than control soils. Overall, my dissertation identifies many influences of land management and climate change on soil microbial communities and shows that these microorganisms will influence forest responses to global change at the ecosystem scale.

In this project, we have designed and synthesized a new series of long-chain, water-soluble, dendritic, anionic amphiphiles [3CAmn, RCONHC(CH₂CH₂COOH)₃, R= CnH2n+1] to alleviate the low aqueous solubility of fatty acids. The dendritictricarboxlyato headgroup improves aqueous solubility and allows us to measure the intrinsic biological activity of our amphiphiles without the potential hindrance of low aqueous solubility. The aqueous solubilities of the anionic amphiphiles have been measured and were vastly higher than that of fatty acids. For example, 3CAm17 (1700 μM at pH 7.2) has much better aqueous solubility than the C₁₈ fatty acid analog (<<1 micromol at pH 7.4). Following the determination of aqueous solubility, both anionic and nonionic amphiphiles were tested against a wide variety of microorganisms. The anionic amphiphiles were mostly active against Candida albicans (4.4 microgram/mL), Saccharomyces cerevisiae (4.4 μg/mL), and Mycobacterium smegmatis (18 microgram/mL) and exhibited modest activity against both Gram-negative (71–280 microgram/mL) and Gram-positive bacteria (36– >6300 microgram/mL). With the exception of Neisseria gonorrhoeae (9.8 microgram/mL), the nonionic amphiphiles were mostly minimally active or inactive against Gram-negative bacteria (630–5000 microgram/mL). The nonionic amphiphiles were similarly inactive against fungi (625–5000 microgram/mL). However, the nonionic amphiphiles exhibited good activity against M. smegmatis (20 microgram/mL) and exhibited the best activity against Grampositive bacteria, such as MRSA (22 microgram/mL), Staphylococcus aureus (20 microgram/mL), and Micrococcus luteus (20 microgram/mL). The anionic and nonionic amphiphiles were also tested for possible spermicidal and anti-human immunodefiency virus (HIV) activity. The anionic amphiphiles exhibited anti-HIV activity (EC₅₀, 73–340 microgram/mL), but lacked spermicidal activity. The series had comparable anti-HIV activity to the commercial product N-9 (80 microgram/mL). Except 3CAm13, all anionic amphiphiles (1.4–4) had better selectivity indices than that of N-9 (0.9). The nonionic amphiphiles exhibited both anti-HIV (44–67 microgram/mL) and spermicidal activity (226–2000 microgram/mL). The nonionic amphiphile were more spermicidal and antiviral than Nonoxynol-9. In addition to biological activity, we determined whether the anionic amphiphiles could be utilized as corrosion inhibitors or ore flotation enhancers. The anionic amphiphiles formed stable thin films on silver oxide that were resistant to ethanol washings. We also measured the water contact angles of the anionic amphiphiles on mineral surfaces [apatite (95°), calcite (92°)]. / Ph. D.

Many previous studies of biological activity in a homologous series of amphiphiles have shown a cut-off effect, where the biological activity increases with an increase in chain length, after which the activity plateaus or weakens. One factor suspected to cause this problem is solubility issues. We have designed several series of very hydrophobic, water-soluble amphiphiles to overcome this problem. Three homologous series containing mobile hydrophobic moieties and two series of epimers containing rigid cholestane moieties have been synthesized; the hydrophobic moiety is connected to the first-generation, Newkome-type dendron via a ureido linker. We have demonstrated that as tris(triethanolammonium) salts, these amphiphiles show excellent solubility in water. The solubilities in aqueous triethanolamine solution of the three series containing mobile hydrophobic moieties are 19,500 to 25,700 μM depending on the formula weight of the homolog, while those containing rigid cholestane moieties are 18,900 and 17,400 μM. Having eliminated the solubility issue, the antimicrobial activity against a broad spectrum of microorganisms has been screened. We have demonstrated that the antimicrobial activity depends on the amphiphile-series, species, chain-length, or epimer specificities, as well as hydrophobicity. The one-tailed, tri-carboxylato amphiphiles are generally better than the other series, with two exceptions. First, the two-tailed tri-carboxylato amphiphiles, <b>3CUr1(11)₂</b> and <b>3CUr1(12)₂</b>, are more active against <i>Cryptococcus neoformans</i>; in fact, both amphiphiles (MICs are 6.9 and 7.2 μM, respectively) are considered to display good antifungal activity. Second, amphiphile <b>3CUr-β-cholestane</b>, whose MIC is 27 μM, is more active against <i>Staphylococcus aureus</i>. Overall, these new tri-carboxylato amphiphiles only exhibit moderate activity with two promising leads. Furthermore, we have demonstrated the intrinsic activity (MIC₀) of the one-tailed, tri-carboxylato amphiphile series (<b>3CUrn</b>) against <i>Mycobacterium smegmatis</i>. All the MIC₀s observed are at least 8-fold lower than the corresponding CMCs. Amphiphile <b>3CUr16</b> is the most active; the MIC₀ is 100-fold smaller than the CMC. With this consideration, we have suggested that the mechanism of action of the antimycobacterial activity in amphiphile <b>3CUr16</b> is not related to detergency. / Ph. D.

Continuous-flow microwave heating is an alternative processing technology that can bring advantages to the pasteurization of food products, particularly, fruit-based beverages. This work aimed to study the continuous-flow microwave thermal processing of cloudy apple juice. Dielectric and electric properties of cloudy apple juices, obtained from different varieties and from an industrial plant, were determined from 500 to 3000 MHz and temperatures between 10 °C and 90 °C. At these frequencies, apple variety showed little influence and the permittivity decreased almost linearly with temperature. Inactivation kinetics of pathogen microorganisms (Escherichia coli O157:H7 and Listeria monocytogenes) and enzymes (polyphenol oxidase, peroxidase and pectin methylesterase) were studied and modeled to evaluate non-thermal effects of microwave radiation. For both processing technologies, it was possible to achieve a 5-log10 reduction of E. coli and L. monocytogenes, as recommended by the FDA. Microwave processing in comparison to conventional heating enhanced the microorganism inactivation in 18 out of 28 experiments. Predicted enzyme inactivation curves for pasteurization at 70 °C and 80 °C of the cloudy apple juice showed that pectin methylesterase has the highest thermal resistance and that there was no significant evidence of non-thermal microwave effects. A pilot scale unit used for pasteurizing fruit juices was evaluated and the process was modeled and simulated to determine the average time-temperature history. Mean residence times and dispersion parameters were obtained from internal volume measurements and residence time distribution experiments. Thermal processing experiments using water provided heat transfer coefficients as functions of Reynolds number and also microwave power absorption. Mathematical modeling was used to determine the temperature distribution along the product path and results were validated. Results showed that focused microwave heating provided the necessary temperature increase in a very short time, with a lethality contribution of only 0.7% as compared to 59-68% when using the conventional heat exchanger, which configures over-processing and can decrease product quality. Fresh cloudy apple juice was subjected to continuous flow microwave assisted pasteurization in a pilot scale unit at three processing temperatures (70 °C, 80 °C and 90 °C), two flow rate levels and two heating systems (conventional and focused microwave). Good results were obtained for polyphenol oxidase and peroxidase inactivation, but not for pectin methylesterase, which showed to be the most resistant enzyme. A comparative evaluation on quality changes was performed in cloudy apple juice samples pasteurized in the continuous-flow unit. Profile of volatiles of the microwave pasteurized apple juice was more similar to the nonpasteurized juice, in comparison with the conventionally pasteurized juice. However, total organic acids and total soluble sugar contents were not significantly different between both processing technologies. There was an increase of phenolic contents during processing of cloudy apple juice, possibly due to the extraction of phenolic compounds present in suspension of material. Furthermore, it was observed the same trend of antioxidant capacity by DPPH and ORAC methods. In conclusion, this PhD work presents the potential of the microwave-assisted pasteurization in cloudy apple juice regarding enzymatic, microbiological and quality aspects. / Aquecimento de micro-ondas de fluxo contínuo é uma tecnologia de processamento alternativa que pode proporcionar vantagens para a pasteurização de produtos alimentícios, particularmente, bebidas à base de frutas. Este trabalho teve como objetivo estudar o processamento térmico de micro-ondas de fluxo contínuo em suco de maçã não clarificado. As propriedades dielétricas e elétricas dos sucos de maçã não clarificados, obtidos de diferentes variedades de maçãs e de uma planta industrial, foram determinadas entre 500 e 3000 MHz e temperaturas entre 10 °C e 90 ° C. Nessas frequências, a variedade da maçã apresentou pouca influência e a permissividade elétrica diminuiu quase linearmente com a temperatura. Cinéticas de inativação de microrganismos patogênicos (Escherichia coli O157: H7 e Listeria monocytogenes) e enzimas (polifenol oxidase, peroxidase e pectina metilesterase) foram estudadas e modeladas a fim de avaliar os efeitos não térmicos da radiação de micro-ondas. Para ambas tecnologias de processamento foi possível obter uma redução de 5-log10 de E. coli e L. monocytogenes, como recomendado pelo FDA. O processamento de micro-ondas em comparação com o aquecimento convencional aumentou a inativação dos micro-organismos em 18 dos 28 experimentos. As curvas de inativação enzimática preditas para pasteurização a 70 ° C e 80 ° C do suco de maçã mostraram que a pectina metilesterase possui a maior resistência térmica e que não houve evidência de efeitos não térmicos. Uma unidade de escala piloto usada para pasteurizar sucos de frutas foi avaliada e o processo foi modelado e simulado para determinar o histórico de tempo-temperatura. Os tempos médios de residência e os parâmetros de dispersão foram obtidos a partir de experimentos de distribuição do tempo de residência e volumes. Experimentos do processamento térmico utilizando água, como produto alimentício, forneceram coeficientes de transferência de calor em função do número de Reynolds e absorção de energia de micro-ondas. A modelagem matemática foi utilizada para determinar a distribuição de temperatura do percurso do produto, e posteriormente, foram validados. Os resultados mostraram que o aquecimento por microondas focalizadas proporcionou o aumento necessário da temperatura em um tempo curto, com uma contribuição de letalidade de apenas 0,7% em comparação a 59-68%, quando usado somente o trocador de calor convencional, o que configura sobre processamento, podendo diminuir a qualidade do produto. O suco de maçã fresco não clarificado foi submetido à pasteurização por micro-ondas em fluxo contínuo em uma unidade de escala piloto em três temperaturas de processamento (70 ° C, 80 ° C e 90 ° C), dois níveis de vazão e dois sistemas de aquecimento (convencional e micro-ondas). Resultados positivos foram obtidos para polifenol oxidase e peroxidase, mas não para a pectina metilesterase demonstrando ser a enzima mais resistente. Uma avaliação comparativa das mudanças de qualidade foi realizada em amostras de suco de maçã pasteurizado na unidade de fluxo contínuo. O perfil de voláteis do suco de maçã pasteurizado por microondas foi mais semelhante ao suco não pasteurizado em comparação ao suco pasteurizado convencionalmente. Entretanto, ácidos orgânicos totais e açúcares solúveis totais não foram significativamente diferentes no processamento por estas duas tecnologias. Houve um aumento de compostos fenólicos durante o processamento do suco de maçã não clarificado, possivelmente devido a extração de compostos fenólicos presentes no material em suspensão. Além disso, foi observado a mesma tendência na atividade antioxidante determinada pelos métodos de DPPH e ORAC. Em conclusão, este trabalho de doutorado apresenta o potencial da pasteurização por micro-ondas em suco de maçã não clarificado quanto aos aspectos enzimáticos, microbiológicos e de qualidade.

Sabe-se que humanos, plantas e animais são colonizados por uma elevada diversidade de microrganismos e que esses organismos eucariotos dependem destes microrganismos para manutenção do seu desenvolvimento. Usando dois modelos de associação microrganismo-hospedeiro, foi testado a hipótese de que hospedeiros pertencentes a domínios da vida distintos, apesar de suas particularidades estruturais, genotípicas, filogenéticas e fisiológicas, compartilham similaridades nos modos de associação com a comunidade bacteriana. Sendo assim, o objetivo do presente trabalho foi mapear a comunidade bacteriana associada a plantas do gênero Anthurium endêmicas e/ou não. Paralelamente, mapear a comunidade bacteriana associada a gêneros distintos de cianobactérias, ao longo da curva de crescimento e quando esta é submetida a condições de cultivo distintas. Como resultados, primeiramente, foi observado que plantas Anthurium alcatrazense endêmicas da Ilha apresentam riqueza e diversidade menor que as plantas da espécie Anthurium loefgrenii coletada na ilha de Alcatrazes e também menor que as plantas Anthurium intermedium e Anthurium pentaphyllum coletadas na região de continente. Também foi observado que a estrutura da comunidade bacteriana associada as plantas de A. alcatrazense é distinta quando comparada com as plantas coletadas no continente e também da própria ilha de Alcatrazes. Essa dissimilaridade foi principalmente representada por OTUs afiliadas à Betaproteobacteria e Gammaproteobacteria. Esses resultados sugerem especificidade microrganismo-hospedeiro. Considerando a associação cianobactéria e bactérias heterotróficas, os resultados demonstraram que a comunidade bacteriana associada é especifica de acordo com o gênero de cianobactéria, composta principalmente por classes apresentando abundância relativa de sequencias distintas como, Betaproteobacteria, Gammaproteobacteria, Flavobacteria e Cytophagia. Por outro lado, foi possível observar que ao longo das fases de multiplicação da linhagem Microcystis aeruginosa, ocorre uma sucessão de grupos bacterianos, sendo principalmente representado pela variação da abundância de Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria e Flavobacteria relativo a fase estacionaria de multiplicação. Quando submetida em condições de cultivo distintas, foi possível observar que variações nas taxas de multiplicação da cianobactéria influenciaram uma modulação da estrutura da comunidade bacteriana associada, desta forma sugerindo que rápidas alterações na estrutura da comunidade bacteriana associada a M. aeruginosa, é resultado de processos de auto-regulação entre cianobactéria e bactérias heterotróficas associadas. De forma geral, pode-se sugerir que hospedeiros distintos apresentam padrões de associações com as bactérias similares, podendo estas similaridades sugerir estratégias para um melhor entendimento e manejo dos ecossistemas. / It is known that humans, plants and animals are colonized by a high diversity of microorganisms and that these eukaryotic organisms depend on these microorganisms to maintain their development. Using two microorganism-host association models, we hypothesized that hosts belonging to distinct domains of life, despite their structural, genotypic, phylogenetic and physiological particularities, share similarities in the modes of association with the bacterial community. Thus, the objective of this work was to map the bacterial community associated with plants of the genus Anthurium endemic and / or not. In parallel, map the bacterial community associated with distinct genera of cyanobacteria, along the growth curve of and when it is submitted to different culture conditions. In this context, we observed that Anthurium alcatrazense plants endemic to the Island, present less richness and diversity than the plants of the species Anthurium loefgrenii collected in the island of Alcatrazes and smaller than the plants Anthurium intermedium and Anthurium penthaphyllum collected in the continent. We found that the structure of the bacterial community associated with the plants of A. alcatrazense is distinct when compared to the plants collected in the continent and island of Alcatrazes itself. This dissimilarity was mainly represented by OTUs affiliated with Betaproteobacteria and Gammaproteobacteria. These results suggest microorganism-host specificity. Considering the association cyanobacteria and heterotrophic bacteria, the results demonstrated that the associated bacterial community is specific according to the genus of cyanobacteria, composed mainly by abundance distinct from those of classes, Betaproteobacteria, Gammaproteobacteria, Flavobacteria and Cytophagia. On the other hand, it was possible to observe that during the multiplication stages of the Microcystis aeruginosa strain, a succession of bacterial groups occurs, mainly represented by the variation of the abundance of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Flavobacteria relative to the stationary phase of multiplication. When submitted under different culture conditions, it was possible to observe that variations in cyanobacteria multiplication rates influenced a modulation of the associated bacterial community structure, thus suggesting that rapid changes in the bacterial community structure associated with M. aeruginosa is a result of processes of self-regulation between cyanobacteria and associated heterotrophic bacteria. In general, distinct hosts show patterns of associations with similar bacteria, and these similarities may suggest strategies for a better understanding and management of ecosystems.

Os pacientes com Síndrome de Down (SD) possuem grande incidência de doença periodontal (DP), caracterizada por um curso precoce e com maior severidade. O estudo de metaboloma pode contribuir para o entendimento deste curso da doença, identificando possíveis metabólitos como biomarcadores nestes indivíduos. Para entender o perfil metabolômico dos indivíduos com síndrome de Down e a sua relação com a doença periodontal, realizamos a identificação de metabólitos salivares de adolescentes e adultos jovens, entre 12 e 21 anos, ambos os gêneros. Foram coletados dados sobre o estado geral de saúde e realizados exames clínicos bucais, como índice de higiene oral simplificado, sangramento e profundidade de sondagem. Para a análise do metaboloma foi coletada amostra de saliva não estimulada, analisadas por meio de cromatografia gasosa acoplada á espectrometria de massas. Saliva e fluido crevicular gengival também foram coletados para identificação microbiana através do MALDI-TOF. Os dados encontrados foram submetidos a análise estátisca por meio da Análise dos Componentes Principais (PCA) e quantificação relativa dos metabólitos foi avaliada por testes não paramétricos, Mann-Whitney e Kruskal-Wallis. Foi possível observar através dos modelos de PCA separação dos indivíduos com SD e controles, independente da doença periodontal. A quantificação relativa revelou maiores níveis de glicina, lprolina, l-leucina, l-serina, ácido palmítico, ácido pentanóico, ácido tetradecanóico, tirosina e l-fenilalanina nos grupos SD quando comparados aos controles. Controles com DP também apresentaram níveis elevados de glicina, l-alanina, l-serina e manopiranose quando comparados com controles saudáveis. A microbiota de indivíduos com SD apresentous diferenças siginificantes em relação aos individuos controles, principalmente para Rothia dentocariosa, Staphylococcus epidermidis, Tannerella forsythia quando avaliado a saliva e A. Actinomycetemcomitans, Micrococcus luteus, Rothia aeria, Treponema denticola no fluido crevicular gengival. Em conclusão, o perfil metabolômico impresso nos indivíduos com SD difere significativamente dos indivíduos controles, independente da doença periodontal. Entretanto, os metabólitos que diferenciam indivíduos controles com e sem DP, apresentam-se elevados em todos indivíduos com SD, promovendo novos \"insights\" para o perfil metabólico relacionado a DP na SD. / Down Syndrome (DS) patients have a high incidence of periodontal disease (PD), characterized by an early course and greater severity. The metabolome study may contribute to the understanding of the disease course, identifying possible metabolites as biomarkers in these individuals. To understand the metabolomic profile of the DS and their relationship with PD, we conducted the identification of salivary metabolites of adolescents and young adults between 12 and 21 years, both genders. Data were collected on general health and was performed oral clinical examination, as the IHOS, bleeding index and probing depth. For metabolome analysis was collected unstimulated saliva sample, analyzed by gas chromatography coupled to mass spectrometry. Saliva and gingival crevicular fluid were also collected for microbial identification by MALDI-TOF. Data were submitted to analysis-statistic by PCA and relative quantification of metabolites was evaluated by Mann-Whitney and Kruskal-Wallis tests. It can be observed through the PCA models separation of DS groups and controls groups, regardless of periodontal disease. Relative quantification showed higher levels of glycine, L-proline, L-leucine, L-serine, palmitic acid, pentanoic acid, tetradecanoic acid, tyrosine and L-phenylalanine in the SD groups when compared to controls groups. Controls with PD also showed high levels of glycine, L-alanine, L-serine and mannopyranose compared with healthy controls. The microbiota of individuals with DS groups show significant differences compared to control groups, especially for Rothia dentocariosa, Staphylococcus epidermidis, Tannerella forsythia when evaluated saliva and A. actinomycetemcomitans, Micrococcus luteus, Rothia aeria, Treponema denticola in gingival crevicular fluid. In conclusion, the printed metabolomic profile in individuals with Down syndrome differs significantly from control subjects, regardless of periodontal disease. However, the metabolites that distinguish controls group with and without PD, show up high in all DS individuals, promoting new \"insights\" to the metabolic profile related to PD in DS.