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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.
121

Avaliação dos efeitos causados por contaminações bacterianas em fermentações etanólicas de primeira geração utilizando metodologias multi-ômicas / Multi-omics analyzes of bacterial contaminations in first-generation ethanolic fermentations

Lopes, Lucas Souza 17 June 2019 (has links)
O etanol possui grande importância estratégica para o setor energético brasileiro devido a sua natureza renovável e grande capacidade de geração de emprego e renda. Atualmente um dos principais desafios enfrentados pelas indústrias brasileiras de produção de etanol é a presença de bactérias contaminando as fermentações. Essas atuam modificando o sistema, competindo por nutrientes essenciais, produzindo compostos tóxicos para a levedura e induzindo processos indesejáveis para a indústria como a floculação. Para equilibrar as populações e controlar os efeitos negativos é necessário uma melhor compreensão dos mecanismos genéticos e fisiológicos envolvidos nas interações de bactérias e leveduras em fermentações em fermentações etanólicas de primeira geração (1G). Neste sentido o presente trabalho realizou o sequenciamento, montagem e anotação completa dos genomas de três linhagens bacterianas isoladas diretamente de usinas brasileiras de produção de etanol: Lactobacillus sp. I-2, Lactobacillus sp. L-10 e Acetobacter sp. A-3. Além disso, foram feitas simulações da condição de co-existência entre bactérias lácticas e Acéticas com as leveduras de S. cerevisiae em fermentações semi-industriais em batelada alimentada (\"Melle-Boinot\") com tratamento ácido e reciclo de células. Três condições experimentais foram avaliadas: (i) fermentações contendo apenas leveduras de S. cerevisiae CAT-1, (ii) fermentações contendo leveduras de S. cerevisiae CAT-1 e bactérias de Lactobacillus sp. I-2, e (iii) fermentações contendo leveduras de S. cerevisiae CAT-1 e bactérias de Acetobacter sp. A-3. Por fim, os metabolomas das bactérias e leveduras da condição de coexistência nos ensaios fermentativos foram obtidos por metodologias de cromatografia gasosa acoplada a espectrometria de massas (GC-MS). Foram identificados 3056, 2112 e 3557 genes nos genomas de Lactobacillus sp. L-10, Lactobacillus sp. I-2 e Acetobacter sp. A-3, respectivamente. As leveduras de S. cerevisiae, independente da condição experimental avaliada, consumiram totalmente os açúcares redutores totais (ART) presentes no melaço de cana-de-açúcar ao longo das fermentações em batelada alimentada. A glicina, aminoácido polar contendo apenas um hidrogênio na cadeia lateral, apresentou maior abundância durante as fermentações contaminadas com bactérias lácticas e acéticas em detrimento da condição controle sem contaminação bacteriana. Especula-se que o acúmulo intracelular deste aminoácido seja resultado do desvio de intermediários das vias Glicólise e Ciclo do Ácido Cítrico para a produção de compostos nitrogenados. Provavelmente, ambos os microrganismos, bactérias e leveduras, acumularam glicina no ambiente intracelular como alternativa a deficiência de nitrogênio no melaço de cana-de-açúcar. O sequenciamento dos genomas das bactérias e os ensaios fermentativos em biorreatores foram realizados no Laboratório Nacional de Biorrenováveis (LNBR) do Centro Nacional de Pesquisas em Energias e Materiais (CNPEM). As análises de metabolômica foram realizadas no Laboratório Max Feffer de Genética de Plantas da Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ). Espera-se que os resultados apresentados neste trabalho agreguem mais informações a cerca das interações entre bactérias e leveduras e contribua, num futuro próximo, no apontamento de novas estratégias de controle bacteriano que sejam mais eficientes e sustentáveis que as usadas atualmente em fermentações industriais brasileiras. / Ethanol has great strategic importance for the Brazilian energy sector due to its renewable nature and great capacity to generate jobs and income. Currently, one of the main challenges faced by the Brazilian ethanol industry is the presence of contaminating bacteria in the fermentation tanks. They act by modifying the system, competing for essential nutrients, producing toxic compounds to the yeast and inducing undesirable processes for the industry like flocculation. To better balance populations and to control the negative effects, it is necessary a better understanding of the genetic and physiological mechanisms involved in the interactions among bacteria and yeasts from Saccharomyces cerevisiae. In this sense, the present work carried out the sequencing, assembly and complete genome annotation of three bacterial strains isolated directly from Brazilian ethanol production plants: Lactobacillus sp. I-2, Lactobacillus sp. L-10 and Acetobacter sp. A-3. In addition, simulations of the co-existence condition between lactic and acetic bacteria with yeasts from S. cerevisiae were carried out in semi-industrial fed-batch (Melle-Boinot) fermentations with acid treatment and cell recycling. Three experimental conditions were evaluated: (i) fermentations containing only yeasts from S. cerevisiae CAT-1, (ii) fermentations containing yeasts of S. cerevisiae CAT-1 and bacteria from Lactobacillus sp. I-2, and (iii) fermentations containing yeasts from S. cerevisiae CAT-1 and bacteria from Acetobacter sp. A-3. Finally, the metabolomes of bacteria and yeasts in the coexistence condition on fermentation assays were obtained by gas chromatography coupled to mass spectrometry (GC-MS) and liquid chromatography coupled to mass spectrometry (LC-MS). 3056, 2112 and 3557 genes were identified in the genomes of Lactobacillus sp. I-2, Lactobacillus sp. L-10 and Acetobacter sp. A-3, respectively. The yeasts from S. cerevisiae, regardless of the experimental condition evaluated, all the total reducing sugars (ART) present in sugarcane molasses were consumed and the ethanol production was consistent with that observed in first generation (1G) ethanolic fermentations. Glycine, an apolar amino acid containing only one hydrogen in the lateral chain, showed greater abundance during fermentations contaminated with lactic and acetic bacteria. It is speculated that the intracellular accumulation of this amino acid results from the shift of intermediates from the Glycolysis/Glycogenogenesis and the Citric Acid Cycle pathways to the production of nitrogen compounds. Probably, both microorganisms, bacteria and yeasts, used the intracellular accumulation of glycine as an alternative to nitrogen deficiency in sugarcane molasses in the fermentations carried out in bioreactors. The Bacterial genomes sequencing and fermentation assays in bioreactors were performed at the Brazilian Bioethanol Science and Technology Laboratory (CTBE) of the Brazilian Center for Research in Energy and Materials (CNPEM). The metabolomics analyzes were performed at the Max Feffer Laboratory of Plant Genetics at the \"Luiz de Queiroz\" School of Agriculture (ESALQ). It is hoped that the results presented in this work will add more information about the interactions among bacteria and yeasts and will contribute, in the near future, to new bacterial control strategies in Brazilian industrial fermentations that are more efficient and sustainable than those currently used.
122

Developing Statistical and Analytical Methods for Untargeted Analysis of Complex Environmental Matrices

Bell, Madison 07 January 2021 (has links)
The main objective of this thesis was to develop statistical and analytical methods for untargeted analyses of complex environmental matrices like soil and sediment. Untargeted analyses are notoriously difficult to perform in matrices like soil and sediment because of the complexity of organic matter composition within these matrices. This thesis aimed to (1) Develop and compare extraction methods for untargeted analyses of soil and sediment while also developing data handling and quality control protocols; (2) Investigate novel applications of untargeted analyses for environmental classification and monitoring; and (3) Investigate the experimental factors that can influence the organic matter composition of untargeted extractions. CHAPTER TWO is a literature review of metabolomics protocols, and these protocols were incorporated into a proposed workflow for performing untargeted analysis in oil, soil, and sediment. This thesis contains the first application of untargeted analysis to freshwater lake sediment organic matter (i.e. sedimentomics) in CHAPTER THREE, and this has implications for discovering new biomarkers for paleolimnology (APPENDIX ONE). I demonstrated successful extraction methods for both sedimentomics and soil metabolomics studies in CHAPTER THREE and CHAPTER FIVE, respectively, using the proposed workflow from CHAPTER TWO. I also applied sedimentomics to the classification of lake sediments using machine learning and geostatistics based on sediment organic matter compositions in CHAPTER FOUR; this was a novel application of sedimentomics that could have implications for ecosystem classifications and advance our knowledge of organic matter cycling in lake sediments. Lastly, in CHAPTER FIVE I determined microbial activity, extraction method, and soil type can all influence the composition of soil organic matter extracts in soil metabolomics experiments. I also developed novel quality controls and quantitative methods that can help control these influences in CHAPTER FIVE and APPENDIX THREE. APPENDIX TWO was written in collaboration with multiple researchers and is a review of all “omics” types of analyses that can be performed on soil or sediment, and how methods like the untargeted analysis of soil and sediment organic matter can be linked with metagenomics, metatranscriptomics, and metaproteomics for a comprehensive metaphenomics analysis of soil and sediment ecosystems. In CHAPTER SIX the conclusions and implications for each chapter and overall for this thesis are detailed and I describe future directions for the field. In the end the overall conclusions of this thesis were: 1) Quality controls are necessary for sedimentomics and soil metabolomics studies, 2) Sedimentomics is a valid technique to highlight changes in sediment organic matter, 3) Soil metabolomics and sedimentomics yield more information about carbon cycling than traditional measurements, and 4) Soil metabolomics organic matter extractions are more variable and require more quality controls.
123

Molecular breeding of functional spinaches rich in folate and betacyanin based on metabolome analysis / メタボローム解析に基づく葉酸及びベタシアニン富化機能性ホウレンソウの育種

Ohtani, Yuta 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22487号 / 農博第2391号 / 新制||農||1076(附属図書館) / 学位論文||R2||N5267(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 植田 充美, 教授 梅澤 俊明, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
124

Frailty markers comprise blood metabolites involved in antioxidation, cognition, and mobility / フレイルのマーカーは抗酸化力、認知能、運動能と関連した血液メタボライトを含む

Kameda, Masahiro 23 September 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22732号 / 医博第4650号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 髙橋 良輔, 教授 中山 健夫, 教授 川上 浩司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
125

A MULTIPHASIC PHYLOGENETIC AND GENOMIC CHARACTERIZATION OF THE FUNGAL ENDOPHYTE STEMPHYLIUM STRAIN PNW2016-02 AND A SEMI-AUTOMATED BIOINFORMATIC APPROACH TO INVESTIGATING THE STRAIN SECRETOME

Nathaniel Thomas Tobey (11845817) 20 December 2021 (has links)
<p>As part of development of a human pathogen suppressing in plantae model system within <i>Spinacia oleracea</i>, a known pathogen transmitting produce plants, the secretome of the <i>Stemphylium</i> strain PNW2016-02, an endophytic fungal isolate of spinach plants, was studied. This strain was previously isolated in Purdue University Northwest laboratories in the Biological Sciences Department. As the secondary metabolite secretions of PNW2016-02 were shown to have antibiotic properties against a broad range of bacteria, we sought to improve our understanding of these properties and other characteristics of PNW2016-02 by sequencing and annotating the genome of this strain. Chemical compound characterization was achieved using HPLC-MS, which provided the ability to identify and quantify chemical compounds contained within the PNW2016-02 secretome. Through multi-gene phylogenetic analysis and comparative genomics, we found that PNW2016-02 clusters with a clade representing <i>Stemphylium vesicarium</i>; however, genome annotation also uncovered several genes unique to PNW2016-02. To assist in more fully understanding the secondary metabolites PNW2016-02, a semi-automated bioinformatic pipeline was developed in the R statistical environment in order to reconstruct and characterize the metabolic pathways, especially those pertinent to antibiotic production. Analysis using the bioinformatic pipeline revealed the presence of a number of antimicrobial metabolites, such as flavonoids, and suggests these compounds are produced and transformed in pathways, such as the phenylpropanoid synthesis pathway. These findings also suggest an important vital role of the shikimate pathway for antimicrobial metabolite production within PNW2016-02. Overall, the findings presented here have implications for understanding the antimicrobial strategies employed by <i>Stemphylium</i> PNW2016-02 and its potential for use in the above-mentioned model system.</p>
126

Identification of anti-HIV compounds in Helichrysum species (Asteraceae) by means of NMR-based metabolomic guided fractionation

Heyman, Heino Martin January 2013 (has links)
The plant kingdom contributes significantly to the natural products that are used for the treatment of a large number of ailments and disease across the globe. Included in these species is the Helichrysum genus (Asteraceae), which comprises of more then 600 species across Africa of which 244 species are found in South Africa. Helichrysum species are used in many cases for the treatment of coughs, colds, fever, infection, headaches, menstrual pain and are also very popular for wound dressing due to their potential antibacterial properties. The most common Helichrysum species used in traditional medicine and for several medicinal purposes are H. cymosum, H. odoratissimum, H. petiolare and H. nudifolium. Previously published research has shown that several of the Helichrysum species do have antimicrobial activity with the most relevant to this study being the discovery of antiviral activity of H. aureonitens against herpes simplex virus type 1 (HSV-1) as well as the reports of anti-HIV (human immunodeficiency virus) activity of several Helichrysum species. With this knowledge, a more in-depth study was initiated to identify the possible active constituents in South African Helichrysum species against HIV. Due to the need to speed up drug discovery especially against epidemic diseases like HIV, this study investigated a new tool (nuclear magnetic resonance (NMR) – based metabolomics) to speed up drug discovery form natural products especially when anti-viral constituents are investigated. odoratissimum, H. petiolare and H. nudifolium. Previously published research has shown that several of the Helichrysum species do have antimicrobial activity with the most relevant to this study being the discovery of antiviral activity of H. aureonitens against herpes simplex virus type 1 (HSV-1) as well as the reports of anti-HIV (human immunodeficiency virus) activity of several Helichrysum species. With this knowledge, a more in-depth study was initiated to identify the possible active constituents in South African Helichrysum species against HIV. Due to the need to speed up drug discovery especially against epidemic diseases like HIV, this study investigated a new tool (nuclear magnetic resonance (NMR) – based metabolomics) to speed up drug discovery form natural products especially when anti-viral constituents are investigated. In this study very promising anti-HIV results were obtained from several aqueous extracts (1:1 methanol/water) using a full virus model i.e. Helichrysum populifolium (IC50 12 μg/ml), H. appendiculatum (IC50 17 μg/ml), H. cymosum ssp. clavum (IC50 19 μg/ml), H. oxyphyllum (IC50 19 μg/ml) and H. cymosum ssp. cymosum (IC50 21 μg/ml). With the use of NMR-based metabolomics and multivariate data analysis (MVA) the specific characteristic that differentiated the active extracts from the non-active extracts was identified by making use of Orthogonal Projections to Latent Structures – Discriminant Analysis (OPLS-DA). This characteristic was then used as a “blue print” or “fingerprint” to guide the process of fractionation and purification. H. populifolium showed the highest anti-HIV activity and thus was selected as the candidate extract for further analysis. After a very quick and simple chromatographic fractionation process, seven fractions were compared against the activity profile by making use of their NMR profiles, which then visually indicated which of the fractions had the highest similarity. Fraction 6 had the most similar “fingerprint”. The compounds of this active fraction were then identified with the use of liquid chromatography – ion trap – time of flight (LC-IT-TOF) for quick identification. The analysis revealed the presence of five chlorogenic type compounds, 3,4-dicaffeoyl quinic acid (DCQA), 3,5-DCQA, 4,5-DCQA, 1,3,5- tricaffeoyl quinic acid (TCQA) and 5-malonyl-1,3,4-TCQA of which several are well known to have anti-HIV activity ranging from 0.85μM to 12μM. We were thus able to show with this study the possibility of using NMR-based metabolomics guided fractionation to guide the process of fractionation and identification from an active characteristic profile to the active constituents within the active H. populifolium extract. / Thesis (PhD)--University of Pretoria, 2013. / gm2014 / Plant Science / unrestricted
127

Evaluation de l’approche métabolomique pour l’étude de la métabolisation et des effets du diclofénac chez la moule méditerranéenne / Metabolomics assessment to study biotransformation and effects of diclofenac on mediterranean mussel Mytilus galloprovincialis

Bonnefille, Bénilde 25 September 2017 (has links)
Le travail de thèse présenté dans ce manuscrit porte sur la caractérisation de l’exposition des organismes aquatiques à un produit pharmaceutique (PP) et sur l’étude des perturbations métaboliques associées. Un PP récemment inclus dans la liste de vigilance de la directive cadre sur l’eau européenne (2015/495/EC), le DCF, et un organisme du milieu marin, Mytilus galloprovincialis, ont été choisis comme modèles de travail. L’approche méthodologique développée est une combinaison de l’analyse ciblée et non-ciblée des métabolites endogènes et exogènes (l’endo- et le xéno-métabolome) présents chez l’organisme d’étude suite à une exposition au DCF. L’évaluation des effets du DCF chez la moule par approche ciblée a été conduite sur la base de son mode d’action connu chez l’Homme : la modulation de la synthèse des prostaglandines (PG). Les PGs sont impliquées dans diverses fonctions, telles que la reproduction et l’osmorégulation chez les organismes aquatiques, et d’autres voies métaboliques sont susceptibles d’être impactées. Les résultats obtenus ont permis de mettre en évidence une sous-modulation de la synthèse de la PGE2 chez les moules exposées au DCF. Par ailleurs, peu d’informations sont disponibles concernant la métabolisation du DCF chez les invertébrés. Pour étudier la biotransformation et les effets du DCF chez la moule, l’application d’une approche non-ciblée nous semblait prometteuse. L’étude du xéno-métabolome m’a permis de mettre en évidence la formation de 13 métabolites, dont 3 de phase I et 10 de phase II. Parmi ces métabolites, 5 sont référencés pour la première fois dans la littérature. Par la suite, l’étude de l’endo-métabolome a permis de révéler la modulation de deux voies métaboliques : le métabolisme de la tyrosine et le métabolisme du tryptophane. Les catécholamines et la sérotonine ressortent comme particulièrement impactées dans ces deux voies métaboliques. Chez la moule, ces métabolites sont impliqués dans des fonctions biologiques importantes : l’osmorégulation et la reproduction et sont en accord avec les études menées chez d’autres organismes aquatiques. Le travail effectué a permis de mettre en évidence que l’application de l’approche métabolomique à des questions environnementales est pertinente et performante pour étudier la biotransformation et les effets non-documentés (différent du mécanisme d’action connu) d’un produit pharmaceutique chez des organismes non-cibles, sans hypothèse a priori. / This PhD thesis describes an investigation of the metabolomic approach performances to characterize the pharmaceuticals environmental exposure and effects in non target organisms. The studied pharmaceutical was diclofenac (DCF), a non-steroidal anti-inflammatory drug recently included in the first watch list of the European Water Framework Directive (2015/495/EC), and the model organism was the Mediterranean mussel Mytilus galloprovincialis. The methodological approach combines target and non-targeted analysis of endogenous and exogenous metabolites in mussel, the endo- and the xeno-metabolome. DCF effects in mussel were investigated considering its known mode of action in human: the prostaglandins (PG) synthesis modulation. In aquatic organisms, PGs are involved in various biological functions, such as reproduction or osmoregulation. This targeted analysis allowed us to determine a PGE2 synthesis disruption with DCF exposure. Otherwise, little information is available about DCF biotransformation in invertebrates. To study DCF biotransformation in mussel, the application of a non-targeted approach seemed promising. This study allows the reveal 13 DCF metabolites formation of which 3 were phase I metabolites and 10 were phase II metabolites. Among them, 5 were described for the first time. Subsequently, the mussel’s endo-metabolome study showed the modulation of two pathways: the tyrosine and the tryptophan metabolism. Inside these pathways, the catecholamines and serotonin appeared as particularly impacted. In mussels, these compounds are involved in important biological functions: the osmoregulation and the reproduction. Such DCF effects are in accordance with those reported in other study conducted on aquatic organisms. The work conducted highlighted the relevance and pertinence of the metabolomic approach as a tool for environmental studies without a priori hypothesis, such as studying the biotransformation and unexpected effects of pharmaceuticals in non-target organisms.
128

NMR Metabolomics for Optimizing Cell-Free Protein Synthesis

Campo, Angela M. 09 June 2021 (has links)
No description available.
129

Utilisation de la métabolomique pour l'étude de l'encéphalopathie hépatique et développement de nouvelles approches pour l'acquisition de données par spectrométrie de masse / Application of metabolomics for the study of hepatic encephalopathy and development of new data acquisition protocols in mass spectrometry

Barbier Saint Hilaire, Pierre 10 July 2019 (has links)
La métabolomique non ciblée est une approche visant à caractériser le contenu métabolique d’un échantillon biologique. Cela permet d’évaluer les changements phénotypiques ayant lieux en son sein. Au cours de cette thèse, une cohorte de patients souffrant d’encéphalopathie hépatique (EH) a été étudiée en métabolomique, en association avec de la lipidomique et de la glycomique. L’EH est une maladie dont les mécanismes sont encore mal compris mais avec un impact important médicale et sociétal. Ces travaux ont montré que l’EH est associée à une altération du métabolisme énergétique observable dans le sang et dans le liquide céphalorachidien. A la suite de cette étude et face aux limites mises en exergue, la suite de ces travaux a visé à développer de nouvelles approches analytiques en métabolomique. Nous ainsi avons montré que l’utilisation de nouveaux instruments de type Orbitrap-Fusion, permettant d’atteindre de très hautes résolutions, donne accès à la structure isotopique fine des métabolites ce qui facilite leur l’identification. L’étude de la fragmentation MS² des ions a permis de mieux comprendre des mécanismes mis en jeu, améliorant l'interprétation des spectres. Enfin, nous avons montré que les améliorations apportées aux instruments, notamment en termes de vitesse d’acquisition, permettaient d’envisager la mise en place de nouveaux modes d’acquisition basés sur l’acquisition multi-événements de spectres MS et MS². Ces améliorations proposées devraient rapidement être utilisables et applicables à l'étude métabolomique de nouvelles cohortes médicales. / Untargeted metabolomics aims at studying the whole metabolite content of biological media. This allows to assess phenotypic changes in these samples. In the frame of this work, a cohort of patients suffering from hepatic encephalopathy (HE) was studied using metabolomics, in association with lipidomics and glycomics. HE is a disease still poorly understood, but with high medical and social impact. This work, performed on cerebrospinal fluid and blood samples, demonstrates that HE is associated to an alteration of energy metabolism. Then, considering the limitations of metabolomics raised in our first study, we aim at developing new analytical chemistry methods for metabolomics. We demonstrate that the use of new instrument such as Orbitrap Fusion, which can reach very high resolution, gives acces to isotopic fine structure of metabolites, thus facilitating their identification. Furthermore, the study of ion fragmentation from MS² spectra enabled to better understand the involved mechanisms and should help for interpreting MS² spectra obtained from unknown metabolites. Finally, we showed that improvements achieved with the Orbitrap Fusion instrument in terms of data acquisition speed enables the implementation of new acquisition modes based on multi events MS and MS² acquisition, such as data dependent or data idependant acquisitions. All these improvements in the field of metabolomics should rapidly be applicable to medical cohort analyses.
130

Intelligent Differential Ion Mobility Spectrometry (iDMS): A Machine Learning Algorithm that Simplifies Optimization of Lipidomic Differential Ion Mobility Spectrometry Parameters

Shi, Xun Xun 07 October 2021 (has links)
Glycosphingolipids such as α- and β-glucosylceramides (GlcCers) and α- and β- galactosylceramides (GalCers) are stereoisomers differentially synthesized by gut bacteria and their mammalian hosts in response to environmental insult. Thus, lipidomic assessment of α- and β-GlcCers and α- and β-GalCers is crucial for inferring biological functions and biomarker discovery. However, simultaneous quantification of these stereoisomeric lipids is difficult due to their virtually identical structures. Differential mobility mass spectrometry (DMS), as an orthogonal separation to high performance liquid chromatography used in electrospray ionization, tandem mass spectrometry (LC-ESI-MS/MS), can be used to separate stereoisomeric lipids. Generating LC-ESI-DMS-MS/MS methods for lipidomic analyses is exceedingly difficult demanding intensive manual optimization of DMS parameters that depend on the availability of synthetic lipid standards. Where synthetic standards do not exist, method development is not possible. To address this challenge, I developed a supervised in silico machine learning approach to accelerate method development for ion mobility-based quantification of lipid stereoisomers. I hypothesized that supervised neural network models could be used to learn the relationships between lipid structural characteristics and optimal DMS machine parameter values thereby reducing the total number of empirical experiments required to develop a DMS method and enabling users to “predict” DMS parameters for analytes that lack synthetic standards. Specifically, this thesis describes a supervised learning approach that learns the relationship between two DMS machine parameter values (separation voltage and compensation voltage) and two lipid structural features (N-Acyl chain length and degree of unsaturation). I describe here, iDMS, an algorithm that was trained on 17 lipid species, and can further simulate results of DMS manual method development and suggest optimal parameter values for 47 lipid species. This approach promises to greatly accelerate the development of assays for the detection of lipid stereoisomers in biological samples.

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