Literatura académica sobre el tema "Metaboliti volatili"
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Artículos de revistas sobre el tema "Metaboliti volatili"
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Xu, Yaying, Changqing Zhu, Changjie Xu, Jun Sun, Donald Grierson, Bo Zhang y Kunsong Chen. "Integration of Metabolite Profiling and Transcriptome Analysis Reveals Genes Related to Volatile Terpenoid Metabolism in Finger Citron (C. medica var. sarcodactylis)". Molecules 24, n.º 14 (15 de julio de 2019): 2564. http://dx.doi.org/10.3390/molecules24142564.
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Finger citron (Citrus medica var. sarcodactylis) is a popular ornamental tree and an important source of essential oils rich in terpenoids, but the mechanisms behind volatile formation are poorly understood. We investigated gene expression changes combined with volatile profiling of ten samples from three developing organs: flower, leaf, and fruit. A total of 62 volatiles were identified with limonene and γ-terpinene being the most abundant ones. Six volatiles were identified using partial least squares discriminant analysis (PLS-DA) that could be used as markers for distinguishing finger citron from other citrus species. RNA-Seq revealed 1,611,966,118 high quality clean reads that were assembled into 32,579 unigenes. From these a total of 58 terpene synthase (TPS) gene family members were identified and the spatial and temporal distribution of their transcripts was measured in developing organs. Transcript levels of transcription factor genes AP2/ERF (251), bHLH (169), bZIP (76), MYB (155), NAC (184), and WRKY (66) during finger citron development were also analyzed. From extracted subnetworks of three modules constructed by weighted gene co-expression network analysis (WGCNA), thirteen TPS genes and fifteen transcription factors were suggested to be related to volatile terpenoid formation. These results provide a framework for future investigations into the identification and regulatory network of terpenoids in finger citron.
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Lu, Xinxin, Lei Zhang, Wenyue Huang, Shujiang Zhang, Shifan Zhang, Fei Li, Hui Zhang, Rifei Sun, Jianjun Zhao y Guoliang Li. "Integrated Volatile Metabolomics and Transcriptomics Analyses Reveal the Influence of Infection TuMV to Volatile Organic Compounds in Brassica rapa". Horticulturae 8, n.º 1 (8 de enero de 2022): 57. http://dx.doi.org/10.3390/horticulturae8010057.
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Turnip mosaic virus (TuMV), which is distributed almost all over the world and has a wide range of hosts, mainly brassica crops, was first described in Brassica rapa in the USA. Plant volatile compounds play an important role in the host searching behavior of natural enemies of herbivorous insects. In this study, TuMV-inoculated resistant and susceptible B. rapa lines were tested using volatile metabolome and transcriptome analyses. In volatile metabolome analysis, the volatile organic compounds (VOCs) were different after inoculation with TuMV in resistant B80124 and susceptible B80461, and the degree of downregulation of differentially expressed metabolites was more obvious than the degree of upregulation. Through transcriptome analysis, 70% of differentially expressed genes were in biological process, especially focusing on defense response, flavonoid biosynthetic process, and toxin metabolic process, which indicates that TuMV stress maybe accelerate the increase of VOCs. Integrating the metabolome and transcriptome analyses, after inoculating with TuMV, auxin regulation was upregulated, and ARF, IAA and GH3 were also upregulated, which accelerated cell enlargement and plant growth in tryptophan metabolism. The different genes in zeatin biosynthesis pathways were downregulated, which reduced cell division and shoot initiation. However, the metabolite pathways showed upregulation in brassinosteroid biosynthesis and α-linolenic acid metabolism, which could cause cell enlargement and a stress response. This study determined the difference in volatiles between normal plants and infected plants and may lay a foundation for anti-TuMV research in B. rapa.
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Zheng, Yucheng, Pengjie Wang, Xuejin Chen, Yun Sun, Chuan Yue y Naixing Ye. "Transcriptome and Metabolite Profiling Reveal Novel Insights into Volatile Heterosis in the Tea Plant (Camellia Sinensis)". Molecules 24, n.º 18 (17 de septiembre de 2019): 3380. http://dx.doi.org/10.3390/molecules24183380.
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Tea aroma is a key indicator for evaluating tea quality. Although notable success in tea aroma improvement has been achieved with heterosis breeding technology, the molecular basis underlying heterosis remains largely unexplored. Thus, the present report studies the tea plant volatile heterosis using a high-throughput next-generation RNA-seq strategy and gas chromatography–mass spectrometry. Phenotypically, we found higher terpenoid volatile and green leaf volatile contents by gas chromatography–mass spectrometry in the F1 hybrids than in their parental lines. Volatile heterosis was obvious in both F1 hybrids. At the molecular level, the comparative transcriptomics analysis revealed that approximately 41% (9027 of 21,995) of the genes showed non-additive expression, whereas only 7.83% (1723 of 21,995) showed additive expression. Among the non-additive genes, 42.1% showed high parental dominance and 17.6% showed over-dominance. Among different expression genes with high parental dominance and over-dominance expression patterns, KEGG and GO analyses found that plant hormone signal transduction, tea plant physiological process related pathways and most pathways associated with tea tree volatiles were enriched. In addition, we identified multiple genes (CsDXS, CsAATC2, CsSPLA2, etc.) and transcription factors (CsMYB1, CsbHLH79, CsWRKY40, etc.) that played important roles in tea volatile heterosis. Based on transcriptome and metabolite profiling, we conclude that non-additive action plays a major role in tea volatile heterosis. Genes and transcription factors involved in tea volatiles showing over-dominance expression patterns can be considered candidate genes and provide novel clues for breeding high-volatile tea varieties.
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Xiang, Nan, Hui Xie, Liuwei Qin, Min Wang, Xinbo Guo y Wen Zhang. "Effect of Climate on Volatile Metabolism in ‘Red Globe’ Grapes (Vitis vinifera L.) during Fruit Development". Foods 11, n.º 10 (16 de mayo de 2022): 1435. http://dx.doi.org/10.3390/foods11101435.
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With unique flavor and nutritional value, grapes are popular for eating and for the byproducts obtained in their processing. This study cultivated a popular grape variety, ‘Red Globe’, in two regions with different climates to investigate the discrepancies in their volatiles in response to climate. Saccharides, organic acids and transcriptomic and volatile metabolic analyses were studied separately via GC-FID, RNA sequencing and GC-MS/MS methods during the development of grape berries. In total, 83 volatiles were determined in samples, with (E)-2-hexenal the most abundant. Fatty acid derivatives and terpenoids in grapes showed discrepancies in different climates, and some of them were correlated to specific transcription factors. VvWRKY22 was influenced by climate conditions and was relative to saccharide accumulation. MYB-related transcription factors (TFs) were highly correlated with volatiles that accumulated during fruit ripening, especially decanal. Terpenoids showed correlations with a gene module that contained ERFs and HSFs. The findings support the hypothesis that fruit maturity and volatile formations vary in grape berries under different climates. Moreover, specific TFs could participate in volatile accumulations. The given results not only serve to enrich theoretical knowledge on the regulatory mechanism of volatiles in grapes, but also provide guidance for enhancing grape flavor and aroma by modulating cultivational conditions.
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Xiang, Nan, Yihan Zhao, Bing Zhang, Qiuming Gu, Weiling Chen y Xinbo Guo. "Volatiles Accumulation during Young Pomelo (Citrus maxima (Burm.) Merr.) Fruits Development". International Journal of Molecular Sciences 23, n.º 10 (18 de mayo de 2022): 5665. http://dx.doi.org/10.3390/ijms23105665.
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As widely planted fruits with high nutritional and medical values, pomelos are managed systematically to achieve the largest economic benefits. But the annual shedding of young pomelos, which could be applied as feedstocks for essential oil extraction with their abundant volatiles, leads to a waste of source. The present study selected two commonly planted pomelo (Citrus maxima (Burm.) Merr.) varieties in Southern China, to investigate the volatile profiles during young pomelo fruits development. Combing transcriptomic analysis, this study aimed at identifying the prominent volatile components in young pomelo fruits in order to preferably extract profitable volatiles, as well, increasing the knowledge concerning regulatory roles of transcription factors (TFs) on volatiles accumulation in young pomelos. Totally 29 volatiles were identified, including 14 monoterpenoids and 13 sesquiterpenoids. Diprene was the principal component with the highest amount. Volatiles were generally decreased during fruits development but preferable stages were figured out for volatile collections. 12 and 17 TFs were related to developing time while ERF003 and MYC2 were highly correlated to monoterpenoids. These findings put forward the comprehensive usages of young pomelos and enriched the regulatory roles of TFs on both fruit development and volatiles metabolism.
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Whiting, M. D., G. Paliyath y D. P. Murr. "Analysis of Volatile Evolution from Scald-developing and Nondeveloping Sides of Apple Fruits". HortScience 32, n.º 3 (junio de 1997): 457C—457. http://dx.doi.org/10.21273/hortsci.32.3.457c.
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Apple fruits (Malus domestica Borkh. cv. `Red Delicious') stored for 6 months at 2°C in air were analyzed for headspace volatiles by SPME-GC and for surface components by HPLC of hexane extracts. Analysis of headspace volatiles evolved from whole fruit showed five major volatiles that were identified previously as: acetic acid, hexyl ester; hexanoic acid, butyl ester; octanoic acid, propyl ester; hexanoic acid, hexyl ester; and the sesquiterpene, α-farnesene. No significant differences existed in these volatiles between scald-developing and non-scald developing apples. To explore potential differences in volatile evolution, fruit developing scald were cut (axial plane) into scalding and non-scalding halves for analysis. In all cases, volatile emission was much higher from the non-scalding side of the fruit, and the ratio of volatile levels from non-scalding to scalding averaged greater that 2. Various regions of tissue from the same fruit were extracted in hexane for estimation of levels of α-farnesene and its potential catabolites by HPLC. The levels and proportions of the components were nearly identical to those observed during headspace volatile analysis of half fruit. The results suggest that there are potential differences in α-farnesene metabolism an/or permeability of apple cuticle to volatiles between scald-developing and non-scald developing regions of apple fruit.
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Fitria, Rizki, Djarot Sasongko Hami Seno, Bambang Pontjo Priosoeryanto, Najmah Najmah y Waras Nurcholis. "Cytotoxic Activity of Volatile Compounds in Cymbopogon nardus’ Essential Oils". Justek : Jurnal Sains dan Teknologi 5, n.º 2 (2 de noviembre de 2022): 90. http://dx.doi.org/10.31764/justek.v5i2.10194.
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Abstract: Plants produce a variety of secondary metabolites, one of which is essential oils that contain a variety of volatile compounds and are useful for humans. Cymbopogon nardus contains volatile compounds that can inhibit the proliferation of cancer cells. This research aims to explore the antiproliferation activity of C.nardus’ essential oils with different concentrations against breast cancer Michigan Cancer Foundation-7 (MCF-7) cells. Antiproliferation test was carried out with total cells method using trypan blue and cells were calculated using a microscope. Gas Chromatography-Mass Spectrometer (GC-MS) was performed to identify the volatile compounds. The results showed that the Inhibitory Concentration 50 (IC50) value was 359.6 ppm with an inhibition percent of 44.49% at 170 ppm. Meanwhile, inhibition percent against Vero normal cell was 29.04%, compared to Doxorubicin 35.23%. The dominant volatile compound in C. nardus’ essential oil were Geraniol and Citronellol.Abstrak Tanaman menghasilkan berbagai macam metabolit sekunder, salah satunya dalam bentuk minyak atsiri yang mengandung berbagai macam senyawa volatil yang berguna bagi manusia. Cymbopogon nardus mengandung senyawa volatil yang dapat menghambat proliferasi sel kanker. Penelitian ini bertujuan untuk mengetahui aktifitas antiproliferasi minyak atsiri C. nardus dengan beberapa konsentrasi terhadap sel kanker payudara Michigan State Foundation-7 (MCF-7). Uji antiproliferasi dilakukan dengan metode total sel menggunakan trypan blue dan sel dihitung menggunakan mikroskop. Gas Chromatography-Mass Spectrometer (GC-MS) dilakukan untuk mengidentifikasi senyawa volatil. Hasil menunjukkan bahwa konsentrasi penghambatan 50 (IC50) sebesar 359.6 ppm dengan persen penghambatan sebesar 44.49% pada konsentrasi 170 ppm. Sementara itu, persen ihibisi terhadap sel normal Vero sebesar 29.04%, dibandingkan dengan Doksorubisin yang sebesar 35.23%. Senyawa volatil dominan yang terdapat pada C. nardus adalah Geraniol dan Citronellol.
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Kharasch, Evan D., Jesara L. Schroeder, H. Denny Liggitt, Sang B. Park, Dale Whittington y Pamela Sheffels. "New Insights into the Mechanism of Methoxyflurane Nephrotoxicity and Implications for Anesthetic Development (Part 1)". Anesthesiology 105, n.º 4 (1 de octubre de 2006): 726–36. http://dx.doi.org/10.1097/00000542-200610000-00019.
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Background Methoxyflurane nephrotoxicity results from biotransformation; inorganic fluoride is a toxic metabolite. Concern exists about potential renal toxicity from volatile anesthetic defluorination, but many anesthetics increase fluoride concentrations without consequence. Methoxyflurane is metabolized by both dechlorination to methoxydifluoroacetic acid (MDFA, which may degrade to fluoride) and O-demethylation to fluoride and dichloroacetatic acid. The metabolic pathway responsible for methoxyflurane nephrotoxicity has not, however, been identified, which was the aim of this investigation. Methods Experiments evaluated methoxyflurane metabolite formation and effects of enzyme induction or inhibition on methoxyflurane metabolism and toxicity. Rats pretreated with phenobarbital, barium sulfate, or nothing were anesthetized with methoxyflurane, and renal function and urine methoxyflurane metabolite excretion were assessed. Phenobarbital effects on MDFA metabolism and toxicity in vivo were also assessed. Metabolism of methoxyflurane and MDFA in microsomes from livers of pretreated rats was determined in vitro. Results Phenobarbital pretreatment increased methoxyflurane nephrotoxicity in vivo (increased diuresis and blood urea nitrogen and decreased urine osmolality) and induced in vitro hepatic microsomal methoxyflurane metabolism to inorganic fluoride (2-fold), dichloroacetatic acid (1.5-fold), and MDFA (5-fold). In contrast, phenobarbital had no influence on MDFA renal effects in vivo or MDFA metabolism in vitro or in vivo. MDFA was neither metabolized to fluoride nor nephrotoxic. Barium sulfate diminished methoxyflurane metabolism and nephrotoxicity in vivo. Conclusions Fluoride from methoxyflurane anesthesia derives from O-demethylation. Phenobarbital increases in methoxyflurane toxicity do not seem attributable to methoxyflurane dechlorination, MDFA toxicity, or MDFA metabolism to another toxic metabolite, suggesting that nephrotoxicity is attributable to methoxyflurane O-demethylation. Fluoride, one of many metabolites from O-demethylation, may be toxic and/or reflect formation of a different toxic metabolite. These results may have implications for interpreting anesthetic defluorination, volatile anesthetic use, and methods to evaluate anesthetic toxicity.
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Cozzolino, Rosaria, Matteo Stocchero, Rosa Perestrelo y José S. Câmara. "Comprehensive Evaluation of the Volatomic Fingerprint of Saffron from Campania towards Its Authenticity and Quality". Foods 11, n.º 3 (27 de enero de 2022): 366. http://dx.doi.org/10.3390/foods11030366.
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The volatile profiles of eight saffron samples (seven cultivated and one spontaneous) grown in different geographical districts within the Campania region (southern Italy) were compared. Using headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME/GC-MS), overall, 80 volatiles were identified in the eight landraces. Among them, safranal and its isomers and other related compounds such as isophorones, which are not only key odorants but also pharmacologically active metabolites, have been detected in all the investigated samples. Principal Component Analysis performed on the volatiles’ compounds revealed that the spontaneous sample turned out to be an outlier. In particular, the volatile organic compounds (VOCs) profile of the spontaneous saffron presented four lilac aldehydes and four lilac alcohol isomers, which, to the authors’ knowledge, have never been identified in the volatile signature of this spice. The multivariate statistical analysis allowed the discrimination of the seven cultivate saffron ecotypes in four well-separated clusters according to variety. Moreover, 20 VOCs, able to differentiate the clusters in terms of single volatile metabolite, were discovered. Altogether, these results could contribute to identifying possible volatile signature metabolites (biomarkers) or patterns that discriminate saffron samples grown in Campania region on a molecular basis, encouraging future biodiversity programs to preserve saffron landraces revealing valuable genetic resources.
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Kiyota, H., S. Otsuka, A. Yokoyama, S. Matsumoto, H. Wada y S. Kanazawa. "Effects of highly volatile organochlorine solvents on nitrogen metabolism and microbial counts". Soil and Water Research 7, No. 3 (10 de julio de 2012): 109–16. http://dx.doi.org/10.17221/30/2011-swr.
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The effects of highly volatile organochlorine solvents (1,1,1-trichloroethane, TCET; trichloroethylene, TCE; and tetrachloroethylene, PCE) on soil nitrogen cycle and microbial counts were investigated using volcanic ash soil with different fertilizations. All the solvents significantly inhibited the activity of the cycle under the sealed conditions with 10 to 50 mg/g (dry soil) solvents added. No significant difference between the solvents, and between fertilization plots, was observed. Nitrate ion was not accumulated, and instead, ammonium ion was highly accumulated in the presence of the solvents. Nitrite ion was partially detected, while l-glutaminase activity was inhibited. The growths of ammonification, nitritation, nitratation and denitrification bacteria, and filamentous fungi were significantly inhibited in the presence of 10 mg/g (dry soil) of the solvents.
Tesis sobre el tema "Metaboliti volatili"
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Andreola, Diego <1991>. "Elaborazione di un metodo di analisi per la determinazione di metaboliti volatili che consentono l'individuazione in fase precoce della presenza di muffe in ambienti chiusi mediante GC-MS e desorbimento termico". Master's Degree Thesis, Università Ca' Foscari Venezia, 2018. http://hdl.handle.net/10579/12137.
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La presente tesi conduce alla realizzazione di un metodo analitico efficace prendendo lo spunto iniziale nel lavoro di ricerca svolto da Stephane Moularat, brevettato nel 2012, che ha messo a punto uno schema algoritmico a risposta binaria considerando 16 diversi metaboliti prodotti dalle muffe ed altri 4 composti di natura sesquiterpenica. La risposta positiva o negativa, dovuta alla presenza o meno dei composti indagati nell’aria dell’ambiente campionato, porta ad un risultato definito come Indice di Contaminazione Fungina (ICF). Tale risultato viene dunque tradotto nella presenza (ICF > 0) o assenza (ICF < 0) di muffa nell’ambiente sottoposto all’analisi.
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Hess, Joerg. "Modelling the transport of volatile metabolites in the mouth". Thesis, University of the West of England, Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490457.
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The knowledge of the mechanisms giving rise to halitosis in the mouth is quite limited despite the social constraints the condition imposes and the attendant commercial interest that results. In part, this understanding is limited by the difficulties inherent in undertaking in vivo studies which are further exacerbated by the complexity of the systems under investigation, in particular, the influence of transport mechanisms such as salivary flow, pH, temperature and others had not been investigated. The research described here is based on a new approach to investigate the transport mechanisms contributing to oral malodour emanating from the tongu, dorsum as the main source of volatile compounds in the mouth (Yaegaki and Sanada 1992, Rosenberg and Leib 1995, De Boever and Loesche 1996).
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El-Kader, M. S. A. M. A. "Production of Volatile Secondry Metabolites in Plant Tissue Cultures". Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503643.
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Turon, Violette. "Coupling dark fermentation with microalgal heterotrophy : influence of fermentation metabolites mixtures, light, temperature and fermentation bacteria on microalgae growth". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS201/document.
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La production de microalgues en hétérotrophie présente plusieurs avantages pour la production de biocarburants par rapport à la production autotrophe, comme une productivité plus importante en termes de biomasse et de lipides. Cependant, le développement industriel de ce procédé est limité par les coûts de productions associés au substrat organique (i.e. glucose) et à ceux liés à la stérilisation des fermenteurs. Les effluents de fermentation sombre, composés principalement d’acétate et de butyrate, pourraient être utilisés comme milieux de culture peu onéreux pour la culture hétérotrophe ou mixotrophe de microalgues. Les objectifs de cette thèse étaient i) de mieux appréhender la croissance algale sur des mélanges variés d’acétate et de butyrate en fonction de la présence ou l’absence de lumière et de la température de croissance et ii) d’évaluer la faisabilité d’utiliser des effluents de fermentation non stérilisés pour soutenir la croissance de microalgues oléagineuses. Tout d’abord, un modèle basé sur des bilans de masse a été construit afin de caractériser la croissance hétérotrophe de Chlorella sorokiniana et Auxenochlorella protothecoides (taux de croissance et rendements) sur des mélanges d’acétate et de butyrate. Les résultats ont montré que le rapport acétate:butyrate et la concentration en butyrate étaient deux paramètres clés pour soutenir la croissance hétérotrophe. Puis, il a été démontré que la présence de lumière et l’utilisation d’une température suboptimale (30 °C) pour la croissance algale permettaient de réduire l’inhibition du butyrate en permettant une production de biomasse autotrophe ou en améliorant la croissance sur acétate. Enfin, il a été montré que les microalgues peuvent être compétitives sur l’acétate lors de la croissance sur des effluents bruts de fermentation sombre en présence de bactéries fermentaires, grâce à la croissance rapide des microalgues sur acétate (1.75 j-1) et à un changement drastique des conditions de culture peu favorables à la croissance des bactéries d’origine fermentaireGrowing microalgae in heterotrophic mode present several advantages over autotrophic mode such as a higher productivity in terms of biomass and lipids for biofuels production. Nevertheless, this process is limited by the production cost associated with the organic substrate (i.e. glucose) and fermenters sterilization costs. Dark fermentation effluents, mainly composed of acetate and butyrate, could be used as a low-cost medium to grow microalgae heterotrophically or mixotrophically. The aims of this PhD were i) to optimize microalgae growth on various mixtures of fermentations metabolites using the presence or absence light and different cultivation temperatures and ii) to assess the feasibility of using unsterilized fermentation effluents. First, a model based on mass balance was built to characterize heterotrophic growth rates and yields when Chlorella sorokiniana and Auxenochlorella protothecoides were supplemented with different mixtures of acetate and butyrate. Results showed that the acetate:butyrate ratio and the butyrate concentration per se were two key parameters for promoting heterotrophic growth. Then, further studies showed that the presence of light and the use of suboptimal temperature (30 °C) could reduce the butyrate inhibition on growth by either triggering autotrophic production of biomass or enhancing growth on acetate. Finally, it was shown that microalgae could outcompete fermentation bacteria for acetate when growing on raw dark fermentation effluents, thanks to a fast algal growth on acetate (1.75 d-1) and a drastic change of culture conditions to the detrimental of bacterial growth
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Cheung, William Hon Kit. "Metabolic profiling of volatile organic compounds and enhanced vibrational spectroscopy". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/metabolic-profiling-of-volatile-organic-compounds-and-enhanced-vibrational-spectroscopy(adcff7c7-96e3-4b5a-8d77-4a943b75f211).html.
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Metabolomics is a post genomic field of research concerned with the study of low molecular weight compounds within a biological system permitting the investigation of the metabolite differences between natural and perturbed systems (such as cells, organs and tissues). Rapid identification and discrimination of biological samples based upon metabolic differences and physiological status in microbiology, mammalian systems (particularly for disease diagnosis), plants and food science is highly desirable. Volatile organic compound (VOC) profiling is a novel area of research where the composition of the VOCs emitted by the biological samples can be correlated to its origin and physiological status. The aim of this project was to investigate the applicability of VOC profiling as a potential complementary tool within metabolomics.In this project the discrimination of bacteria using a novel gas phase separation method was investigated and the development of VOC-based profiling tools for the collections of VOCs emitted from biological samples was also studied. The optimisation and validation of a high throughput method for VOC analysis was achieved and this was used to assess wound healing.VOC metabolite profiling was further extended to the discrimination of S. typhimurium contaminated meat; the study was conducted in parallel with metabolite profiling analysis for the analysis of non-volatile small molecules. Finally, enhanced vibrational spectroscopic techniques were applied to the characterisation and screening of dye molecules in contaminated foodstuffs using Raman spectroscopy. This thesis clearly demonstrates that VOC metabolic profiling is a complementary tool within the metabolomics toolbox, one of its great attractions is that it permits the characterisation of biological samples in a rapid and non-invasive manner. The technique provides detailed chemical information regarding the VOC composition present above the headspace of the sample and can be used to understand its physiological status and biological origin. VOCs metabolite profiling will become a valuable tool for non-invasive analysis of many biological systems. Raman spectroscopy is a sensitive and non-destructive technique which can generate detailed chemical and structural information regarding the analyte under investigation with little or no sample preparation needed. The effect of the weak Raman signal can be significantly amplified by coupling the analyte molecule to surfaces of nanoparticles and demonstrated that it is ideal for analysing aqueous dye solutions in a quantitative manner.
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Berrou, Kevin. "Développement d’outils innovants pour l'étude de l’infection chronique". Thesis, Nîmes, 2019. http://www.theses.fr/2019NIME0001.
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Un des enjeux majeurs dans la gestion de la plaie de pied diabétique est l’obtention d’informations permettant d’anticiper l’évolution de ces infections. Actuellement, il n’existe pas d’outils suffisamment efficaces qui permettent de distinguer une plaie colonisée d’une plaie infectée. L’approche proposée est basée sur discrimination de plusieurs bactéries fréquemment retrouvées dans les plaies chroniques de pied diabétique à partir de leur profil métabolique, et plus particulièrement des métabolites volatils qu’elles produisent. En effet, le dynamisme du métabolisme bactérien serait à même de mettre en évidence les changements qui s’opèrent dans la plaie. Dans un premier temps, une nouvelle méthodologie de concentration des métabolites volatils par Stir Bar Sorptive Extraction (SBSE) a été développée. Elle est basée sur l’utilisation de barreaux qui sont placés à la fois dans le milieu de culture et en espace de tête, suivie d’une analyse par GC-MS. La méthode a ensuite été comparée avec une autre méthode de concentration utilisant des fibres (la SPME) et a montré une meilleure capacité de concentration, permettant ainsi une détection plus sensible. Cette méthodologie a ensuite été utilisée pour suivre la production métabolique de six souches bactériennes cultivées dans des conditions mimant la plaie chronique. Grâce à leur profil métabolique, il a été possible de distinguer des espèces bactériennes. De plus, de manière plus surprenante, il a été possible de distinguer deux souches de Staphylococcus aureus présentant des profils de virulence différents. Enfin, une étude en co-culture a mis en évidence que 83% des métabolites produit en culture simple étaient retrouvés, prouvant l’intérêt de la méthodologie pour distinguer des souches bactériennes d’une même espèce au sein d’une plaieOne of the major challenges in the management of diabetic foot wounds is to obtain information to anticipate the evolution of these infections. Currently, there are no sufficiently effective tools to distinguish a colonized wound to an infected wound. The proposed approach is based on the discrimination of several bacteria frequently found in chronic diabetic foot wounds from their metabolic profile, and more specifically the volatile metabolites they produce. Indeed, the dynamism of bacterial metabolism would be able to highlight the changes that are occurring in the wound. First, a new methodology for the concentration of volatile metabolites by Stir Bar Sorptive Extraction (SBSE) was developed. It is based on the use of stir bars that are placed both in the culture medium and in headspace, followed by GC-MS analysis. The method was then compared with another concentration method using the fibres (SPME) and we highlighted a better concentration capacity with a more sensitive detection. This methodology was then used to monitor the metabolic production of six bacterial strains grown under conditions mimicking the chronic wound. Their metabolic profile allowed us to distinguish bacterial species. Moreover, more surprisingly, it was possible to distinguish two strains of Staphylococcus aureus with different virulence profiles. Finally, a co-culture was performed and we showed that 83% of the metabolites produced in simple culture were found, proving the interest of the methodology to distinguish bacterial strains of the same species within a wound
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Sohrabi, Mohsen. "Oral Microbiota and their Volatile Metabolites in Oral Squamous Cell Carcinoma". Thesis, Griffith University, 2016. http://hdl.handle.net/10072/366691.
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The majority of the oral neoplasms are oral squamous cell carcinoma (OSCC) which have been traditionally linked to consumption of tobacco and alcohol. The human papillomavirus (HPV) infection is also significantly associated with OSCC progression. However, the prevalence of this cancer in people with no record of those traditional factors emphasized the possibility of another significant factor that potentially contributes to OSCC. Bacteria have been strongly associated with some cancers especially in gastric cancer. Several microbial metabolites are categorised as carcinogens that suggest the direct and indirect role of microbes in cancer development. The new insight into human microbiome using high- throughput technologies revealed the variation in the human microbiota between healthy adults and cancer patients that have not been achieved using low- throughput methods. The oral microbiota analysis in OSCC using high- throughput technologies limited to the analysis of the bacteria associated with the cancerous site and the analysis of OSCC’s intraoral microbiota is understudied.
The human microbe-metabolite association with cancer was obtained previously, and the results indicated a potential use of human sample metabolites for the differentiation between healthy adults and cancer patients. However, the method employed in those studies was not ideal for the analysis of microbial metabolites independently from human metabolome. This is because that the accuracy and reproducibility of direct human sample metabolomics undergo variations with both human and microbial samples.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
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Moalemiyan, Mitra. "Volatile metabolic profiling to detect and discriminate diseases of mango fruit". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97971.
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Volatile metabolites from headspace gas of mango cultivars Tommy Atkins and Keitt, wounded and inoculated with two pathogens, Colletotrichum gloeosporioides and Lasiodiplodia theobromae or non-inoculated controls were profiled using a GC/MS to develop a technology to discriminate diseases. Several disease discriminatory compounds were identified and classified into three groups: (i) compounds unique to only one treatment; (ii) compounds common to two or more treatments but not to all; and (iii) compounds common to all treatments but with varying in their abundance. 1-pentanol and boronic acid ethyl were detected in only Lasiodiplodia-inoculated mangoes while thujol was observed only in Colletotrichum-inoculated mangoes. Models based on significant mass ions classified up to 100% of the diseases/inoculations. The disease discriminatory compounds and discriminant analysis models developed here could be used in the early detection of postharvest diseases of mango fruit, after validation under commercial conditions.
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Robert-Hazotte, Aline. "Impact du métabolisme des molécules odorantes sur la perception olfactive chez l'Homme". Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCK073.
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L’odorat est le sens qui permet de percevoir des substances volatiles appelées communément odeurs. Il joue un rôle important dans la subsistance et le bien être des individus car il intervient dans la communication avec leur environnement (recherche de nourriture, de partenaire, détection des prédateurs ...). L’efficacité du système olfactif repose en grande partie sur sa sensibilité, qui dépend de l’affinité des molécules odorantes pour leurs récepteurs olfactifs mais aussi d’un mécanisme de clairance enzymatique des molécules odorantes qui évite à ces récepteurs d’être saturés et qui implique les Enzymes du Métabolisme des Odorants ou EMO. En effet, des études récentes ont démontré que dans l’épithélium olfactif, les EMO qui biotransforment les molécules odorantes conduisent à l’arrêt du signal olfactif en désactivant ces molécules, ce qui permet leur élimination et participent donc ainsi in fine à la perception olfactive. Dans ce contexte, l’objectif de ce travail de thèse est d’apporter une meilleure compréhension des mécanismes enzymatiques impliquant les EMO dans la perception olfactive des mammifères et d’étudier plus particulièrement ces mécanismes chez l’Homme.Le premier axe de ce travail, basé sur des analyses physico-chimiques, a consisté à développer une technique innovante de spectrométrie de masse par réaction de transfert de protons (PTR-MS) permettant le suivi en temps réel de la biotransformation des molécules odorantes par les EMO. Cette technique a été utilisée ex vivo sur des prélèvements d’épithélium olfactif et du mucus olfactif de rat et de lapin et également in vivo directement au sein de la cavité nasale humaine. Ainsi, il a été démontré que la biotransformation olfactive de molécules odorantes catalysée par différentes enzymes de type glutathion transférases, carboxylestérases ou dicarbonyl xylulose réductases (DCXR) est un mécanisme très rapide (de l’ordre de la milliseconde) en parfaite adéquation avec la dynamique physiologique du processus olfactif. Ces analyses ont également révélé que la biotransformation des molécules odorantes peut conduire à la production de métabolites volatils odorants pouvant potentiellement participer à la perception olfactive globale en interagissant eux aussi avec les récepteurs olfactifs. Ces différents métabolites ont été formellement identifiés par une technique de chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC-MS).Le second axe de ce travail, reposant sur des analyses psychophysiques, a consisté à évaluer l’impact du métabolisme des molécules odorantes sur la perception olfactive chez l’Homme. Pour atteindre cet objectif, une stratégie originale de modulation de la perception olfactive reposant sur une compétition entre des molécules odorantes métabolisées par une même EMO, développée récemment au sein de l’équipe chez le lapin, a été transposée à l’Homme. La compétition entre des molécules odorantes de type dicétone vis-à-vis de l’enzyme DCXR a tout d’abord été démontrée in vitro par des analyses biochimiques sur l’enzyme recombinante humaine. Une méthode d’analyse par olfactométrie, appliquée à un panel de 40 sujets, a permis de démontrer que ce mécanisme de compétition entre molécules odorantes induit des modulations de la biotransformation de ces molécules conduisant ainsi à des modifications de leur biodisponibilité relative et in fine de leur perception. Ces résultats inédits démontrent que des modulations affectant la biotransformation d’un odorant conduisent instantanément à une modification de sa perception. Ces travaux de thèse précisent la fonction des EMO chez les mammifères et révèlent pour la première fois, chez l’Homme, une participation significative du métabolisme des molécules odorantes dans la perception olfactiveThe sense of smell permits the perception of volatile substances commonly known as odors. This sense plays an important role in the feeding and wellness of individuals because it involves exchanges with their environment (search for food or partners, predators detection…). The efficiency of the olfactory system mainly relies on its sensitivity depending on the odorant affinity for their olfactory receptors but also on an enzymatic clearance mechanism of odorants which involves the Odorant metabolizing Enzymes (OME) to avoid the saturation of the receptors. Recent studies have shown that the biotransformation of odorants by EMO, in the olfactory epithelium, participates in the olfactory perception. Indeed, OME catalyse the deactivation of the odorants and their subsequent elimination which led to the termination of the olfactory signal. In this context, this work aims to provide a better understanding of the enzymatic mechanisms of the OME in mammal olfactory perception and to study more specifically these mechanisms in human.The first axis of this work, based on physicochemical analysis, has consisted to develop an innovative proton transfer reaction mass spectrometry technique (PTR-MS) to allow the analysis in real time of the odorants biotransformation by OME. This technique was first applied ex vivo using rats and rabbits olfactory epithelium and olfactory mucus but also in vivo directly inside the human nasal cavity. Thus, we have demonstrated that the olfactory biotransformation of odorants catalyzed by different enzymes like glutathione transferases, carboxylesterases and dicarbonyl xylulose reductases (DCXR), is a very fast mechanism (few milliseconds). This very high velocity is perfectly consistent with the physiological dynamics of the olfactory process. Moreover, PTR-MS analyzes revealed that the odorants biotransformation could produce volatile metabolites with odorous properties which could participate in the global olfactory perception by interacting also with olfactory receptors. These various metabolites have been formally identified by a gas chromatography-mass spectrometry technique (GC-MS).The second axis, based on psychophysical method, evaluated the impact of the odorant metabolism in the human olfactory perception. For this purpose, an original approach recently developed in the lab, consisting of the modulation of the olfactory perception through a competition between odorants metabolized by the same EMO was transposed from the rabbit model to the human. The metabolic competition between several diketones toward DCXR was first demonstrated by biochemical analysis using the corresponding human recombinant enzyme. Then, an olfactometric study carried out on a 40 subjects panel demonstrated that this competition mechanism between odorants induces modulations of the biotransformation of these molecules and thus leads to modifications of their relative bioavailability and in fine of their perception. These new and significant results demonstrate that modulations impacting odorants metabolism leads immediately to changes in their olfactory perception. This thesis highlights on the function of EMO in mammals and reveals for the first time in human a significant role of the odorant metabolism in olfactory perception
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Bahroun, Najat. "Detection of Salmonella in food samples using exogenous volatile organic compound metabolites". Thesis, Northumbria University, 2017. http://nrl.northumbria.ac.uk/32550/.
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Rapid, sensitive and selective detection and identification of pathogens is required in the prevention and recognition of problems related to food security. Salmonella is one of the dangerous foodborne pathogens. The identification of specific volatile organic compounds (VOCs) produced by Salmonella may contribute in providing a fast and accurate detection method for Salmonella in food samples. In this study, VOCs liberated by Salmonella strains have been identified and quantified via head space-solid phase microextraction coupled to gas chromatography/mass spectrometry (HS-SPME GC/MS). The dominant chemical class of volatiles liberated from Salmonella strains was alcohol compounds. In addition, ester and ketone compounds were also detected. The most sensitive VOCs detected were ethyl octanoate (LOD = 62.0 ng/mL and LOQ = 207 ng/mL) and ethyl decanoate (LOD = 66 ng/mL and LOQ = 219 ng/mL) with the lowest LOD and LOQ when using Rappaport-Vassiliadis Soya peptone (RVS) broth media and polar SPME fiber with polar GC column. The type of culture medium was found to affect the liberated VOCs. For example, 2-heptanone was not detected when S. london and S. stanley were grown in TSB but they were detected and quantified when using BHI as growth media. Also, 1-octanol was detected and quantified in all strains when Salmonella grown in TSB and BHI, and did not detected in all strains when RVS was used as growth media. The research has been extended to include the addition of specific enzyme substrates to the culture medium (RVS). The enzyme substrates are either commercially available or have been synthesised to allow exogenous VOC detection. The specific enzymes targeted in Salmonella were α-galactosidase, C-8 esterase and pyrrolidonyl peptidase. The enzyme substrates used are phenyl α-D-galactopyranoside, 2-chlorophenyl octanoate and L-pyrrollidonyl fluoroanilide respectively. All, except pyrrolidonyl peptidase, are known to give a positive response to Salmonella. This developed methodology was initially applied to pure cultures of S. stanley to evaluate the feasibility of the approach. The developed approach shows potential for future application in food samples to detect and identify Salmonella species in food samples of a level as low as 100 CFU/mL within a 5 h incubation at 37 ºC by the detection of the liberated VOCs. Subsequently the methodology was applied to a range of food samples (milk, cheese, eggs and chicken). It was found that all food samples were Salmonella free; however, false positive was detected due to the presence of other pathogens in the food samples. Inhibition of some of these pathogens in milk and cheese samples was achieved with the addition of 5 mg/L vancomycin and 10 mg/L of novobiocin. To improve the method specificity, it was necessary to deviate from the standard method and use Salmonella selective RVS broth in pre-enrichment step than using non selective one (BPW). This results in a successful detection of Salmonella contamination on milk samples and cheddar cheese samples. However, failed in detect Salmonella in other cheeses. Inhibition of resistant pathogens (Streptococcus salivarius ssp. Thermophilus, Lactobacillus rhamnosus and Enterococcus faecalis) using another combination of selective agents (vancomycin 10 mg/L, novobiocin 10 mg/L, erythromycin 0.75 mg/L and lithium chloride 15 g/L) failed. This study highlighted the benefits of the use of specific enzyme substrates along with antibiotics into Salmonella VOC analysis to improve the specificity of Salmonella detection method. The results of VOC analysis of specific enzymes inherent within Salmonella could be extended to develop a selective portable sensor approach to be used in food production.
Libros sobre el tema "Metaboliti volatili"
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Sayyed, R. Z. y Virgilio Gavicho Uarrota, eds. Secondary Metabolites and Volatiles of PGPR in Plant-Growth Promotion. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07559-9.
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Smith, Neil A. Metabolism of dimethyl disulphide, carbon disulphide and other volatile sulphur compounds by chemolithoautotrophic sulphur bacteria. [s.l.]: typescript, 1988.
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H, Cummings John, Rombeau John L y Sakata Takashi, eds. Physiological and clinical aspects of short-chain fatty acids. Cambridge: Cambridge University Press, 1995.
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Krupke, Oliver A. The significance of volatile antifungal metabolites produced by trichomerma harzianum biotype Th4, in green-mould disease of commercial mushroom crops. St. Catharines, Ont: Brock University, Dept. of Biological Sciences, 2001.
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Volatiles and Metabolites of Microbes. Elsevier, 2021. http://dx.doi.org/10.1016/c2020-0-00302-6.
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Volatiles and Metabolites of Microbes. Elsevier Science & Technology, 2021.
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Singh, Joginder, Ajay Kumar y Jastin Samuel. Volatiles and Metabolites of Microbes. Elsevier Science & Technology Books, 2021.
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Secondary Metabolites and Volatiles of PGPRs in Plant-Growth Promotion. Springer International Publishing AG, 2022.
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Traul, David E. y Rachel Diehl. Supratentorial Tumors. Editado por David E. Traul y Irene P. Osborn. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190850036.003.0001.
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Surgical resection of supratentorial brain tumors presents a unique set of challenges to the anesthesiologist. While symptoms from these lesions vary in presentation, increased intracranial pressure (ICP) is frequently part of the constellation and an important piece of anesthetic management. Along with maintenance of ICP, the goals of induction, maintenance, and emergence from these resections are to maintain cerebral blood flow (CBF) and cerebral metabolic rate and optimize neuroprotection. There is no single technique that is agreed upon in literature to encompass these goals, however a combination of IV anesthetics with low-dose volatile agents (0.5 MAC) is common in practice. Management of ICP is the hallmark of these cases since increased ICP may lead to ischemia, poor surgical visualization, and catastrophic herniation.
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Vairappan, Charles S. Ecological Chemicals as Ecosystem Function Mediaters and Potential Lead Pharmaceuticals. UMS Press, 2021. http://dx.doi.org/10.51200/ecologicalchemicalsumspress2021-978-967-2962-94-6.
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Relationship between functioning ecosystem services and human wellbeing has been established as a bridge connecting nature and society. It has also become central pillar of sustainability science and dictates the paradigms of sustainable development. But, conceptual frameworks that systematically integrates the important roles played by natural ecological chemicals by establishing empirical links between the nature and ecology not only varies, but lacks clear support. The value of ecological chemicals as ecosystem derived natural products warrants explicit acknowledgement, only then trade-offs between services and prioritization of policy can be realised. In the last 20 years, important roles played by the ecological chemicals in Bornean terrestrial and marine ecosystems were investigated and reported. Terrestrial plants produce Volatile Organic Chemicals (VOCs) and structurally interesting secondary metabolites that facilitate their ecological processes that are aimed to establish communication such as defence, attraction, deterrent and territorial marking. Some of the most commonly utilized herbs and plants of traditional medicine importance showed very interesting chemical constituents, that justify their traditional utilization for human wellbeing. The role of VOCs that originated from animal diet and emitted through decomposition of faeces, was traced back to their important role as attractants of insects, particularly dung beetles that facilitates the remineralization of faeces and returns C and N to soil as to replenish global C and N-sink. Marine flora and fauna are perhaps the most vivid producers of structurally interesting secondary metabolites with more than one ecological functions. Halogenated secondary metabolites produced by red algae Laurencia are unique in their structural design and exhibited multiple biological potentials. Similarly, soft corals in the Sulu-Sulawesi Coral Triangle produced a huge diversity of terpenoids and functions as feeding deterrents of these soft bodied invertebrates. Ecological chemicals obtained from the Bornean biodiversity also exhibited a wide array of medically important biological activities such as anti-microbial, anti-inflammation, anti-anticancer and serves an important array of lead pharmaceuticals. Some of these compounds are very potent and have been patented as lead-pharmaceutical candidates from Bornean natural products. Hence, ecological chemicals are important natural products that regulate ecological processes that ensures ecological balance in tropical ecosystems. Humans who are the custodians of natural ecosystem, stand to benefit directly and indirectly when we practice sustainable utilization and regulation of our natural resources.
Capítulos de libros sobre el tema "Metaboliti volatili"
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Blanck, T. J. J. y E. S. Casella. "Interaction of Volatile Anesthetics with Calcium-Sensitive Sites in the Myocardium". En Cell Calcium Metabolism, 581–91. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-5598-4_60.
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Salwan, Richa, Nidhi Rialch y Vivek Sharma. "Bioactive Volatile Metabolites of Trichoderma: An overview". En Secondary Metabolites of Plant Growth Promoting Rhizomicroorganisms, 87–111. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-5862-3_5.
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Hempel, V., W. Heipertz, H.-V. Gärtner y M. Schmelzle. "Metabolism and Acute Toxicity of Volatile Anesthetics". En Inhalation Anesthetics, 41–44. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-71232-6_6.
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Liu, Yu, Li Zou y Choon Nam Ong. "Untargeted Metabolomic Analysis of Nonvolatile and Volatile Glucosinolates in Brassicaceae". En Plant Secondary Metabolism Engineering, 219–29. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2185-1_18.
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Lauritsen, F. R. y D. Lloyd. "Direct Detection of Volatile Metabolites Produced by Microorganisms". En Mass Spectrometry for the Characterization of Microorganisms, 91–106. Washington, DC: American Chemical Society, 1993. http://dx.doi.org/10.1021/bk-1994-0541.ch007.
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Wüst, Matthias. "Advances in the Analysis of Volatile Isoprenoid Metabolites". En Biotechnology of Isoprenoids, 201–13. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/10_2014_278.
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Wheatley, Ron E. "The Role of Soil Microbial Volatile Products in Community Functional Interactions". En Secondary Metabolites in Soil Ecology, 269–88. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-74543-3_13.
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Roze, Ludmila V., Randolph M. Beaudry y John E. Linz. "Analysis of Volatile Compounds Emitted by Filamentous Fungi Using Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry". En Fungal Secondary Metabolism, 133–42. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-122-6_9.
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Lemfack, Marie-Chantal, Hubert Bahl, Birgit Piechulla y Nancy Magnus. "The Domain of Bacteria and Their Volatile Metabolic Potential". En Bacterial Volatile Compounds as Mediators of Airborne Interactions, 1–38. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-7293-7_1.
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Ibdah, Mwafaq, Andrew Muchlinski, Mossab Yahyaa, Bhagwat Nawade y Dorothea Tholl. "Carrot Volatile Terpene Metabolism: Terpene Diversity and Biosynthetic Genes". En The Carrot Genome, 279–93. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-03389-7_16.
Texto completoActas de conferencias sobre el tema "Metaboliti volatili"
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Jurjevic, Z., G. Rains, D. Wilson, M. Tertuliano, J. Tomberlin y W. Lewis. "86. Volatile Metabolites Associated with Aflatoxigenic and Nontoxigenic Strains of". En AIHce 2006. AIHA, 2006. http://dx.doi.org/10.3320/1.2758993.
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Vrignaud, Marjorie, Zoe Buniazet, Pierre R. Marcoux, Jean Hue, Isabelle Texier-Nogues y Florence Ricoul. "Functionalized nanoporous materials for volatile metabolites monitoring with direct optical transduction". En 2014 IEEE Sensors. IEEE, 2014. http://dx.doi.org/10.1109/icsens.2014.6985154.
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Abdullah, Azian Azamimi, Nur Najwa Amrahuddin y Shigehiko Kanaya. "In silico prediction of biological activity of volatile metabolite using deep learning algorithm". En INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING (ICoBE 2021). AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0111582.
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Martin, J. y P. Gao. "145. Volatile Metabolites Produced by Stachybotrys Chartarum on Rice and Gypsum Board". En AIHce 2000. AIHA, 2000. http://dx.doi.org/10.3320/1.2763472.
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Chaskes, Mark B., Young E. Lee, Elina Toskala, Gurston Nyquist, Bruce Kimball y Mindy Rabinowitz. "Unique Volatile Metabolite Signature of Sinonasal Inverted Papilloma Detectible in Plasma and Nasal Secretions". En 31st Annual Meeting North American Skull Base Society. Georg Thieme Verlag KG, 2022. http://dx.doi.org/10.1055/s-0042-1743698.
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Vashisht, Gaurav, Kantida Koysombat, Rachael Hough, Lauren Lett, Sherry Browne, Naomi Lloyd y Chris Probert. "PWE-125 Effect of turmeric on the faecal volatile organic metabolites in healthy individuals". En British Society of Gastroenterology, Annual General Meeting, 4–7 June 2018, Abstracts. BMJ Publishing Group Ltd and British Society of Gastroenterology, 2018. http://dx.doi.org/10.1136/gutjnl-2018-bsgabstracts.359.
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Finnegan, Jason, Bridget Peterkin, Hee-Chan Han, Jennifer M. Yentes, Stephen I. Rennard y Eric J. Markvicka. "Wireless, Battery Free Wearable Electronic Nose". En 2022 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/dmd2022-1038.
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Abstract Volatile organic compounds (VOCs) are excreted through the skin or exhaled breath. They are end products of human metabolism, metabolism of gut microflora, and ingested or inhaled substances. VOCs can be noninvasively sampled and could be a useful marker for disease. However, medical diagnostics rarely considers the VOCs that are expelled from the body. Here, we introduce a miniature, low-cost, and battery-free electronic nose (e-nose) sensor for passively identifying chemical patterns that are excreted from the human skin or exhaled breath. The platform is composed of an array of conductive polymer filaments created with a two-layer system of multi-walled carbon nanotubes and four different, solution processable polymers. The “breathprint” signature–consisting of the resistance of each filament–can be read from the sensor using a near-field communication-enabled device, such as a smartphone. The e-nose sensor contains a system on a chip with near-field communication (NFC) functionality and a radio frequency antenna to harvest power. The sensor was tested against six common VOCs that are released from the human body.
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Kistenev, Yu V., A. V. Shapovalov, A. V. Borisov y A. I. Knyazkova. "Possibilities of laser spectroscopy for monitoring the profile dynamics of the volatile metabolite in exhaled air". En XXII International Symposium Atmospheric and Ocean Optics. Atmospheric Physics, editado por Gennadii G. Matvienko y Oleg A. Romanovskii. SPIE, 2016. http://dx.doi.org/10.1117/12.2249144.
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Calalb, Tatiana, Cornelia Fursenco, Maria Gonceariuc y Violeta Butnaras. "Studiul microscopic al trihomilor glandulari și nonglandulari la genotipuri de Lavandula Angustifolia Mill. ssp. Angustifolia". En International Scientific Symposium "Plant Protection – Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975347204.63.
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The microscopic and citochemistry study denotes 3 types of glandular trichomes (peltate, capitates type I and type II), implicated in the synthesis of the metabolites, including volatile oils (with biological and protective role) and one type of non-glandular trichomes with the potential adaptive role to stressors in 7 new genotypes (4 cultivars – Moldoveanca 4, Vis Magic 10, Alba 7, Aroma Unica and 3 hybrids – Fr.5S8-24, Fr.8-5-15V and Cr.13S-6-7) of sp. Lavandula angustifolia Mill., spp. angustifolia. The degree of development and distribution mode of both types of trichomes (glandular and non-glandular) varies according organs (stem, leaf, bract, flower calyx and corolla) and genotype.
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Mitsubayashi, Kohji, Po-Jen Chien, Ming Ye, Takuma Suzuki, Koji Toma y Takahiro Arakawa. "Fluorometric biosniffer (biochemical gas sensor) for breath acetone as a volatile indicator of lipid metabolism". En SPIE BioPhotonics Australasia, editado por Mark R. Hutchinson y Ewa M. Goldys. SPIE, 2016. http://dx.doi.org/10.1117/12.2244660.
Texto completoInformes sobre el tema "Metaboliti volatili"
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Galili, Gad, Harry J. Klee y Asaph Aharoni. Elucidating the impact of enhanced conversion of primary to secondary metabolism on phenylpropanoids secondary metabolites associated with flavor, aroma and health in tomato fruits. United States Department of Agriculture, enero de 2012. http://dx.doi.org/10.32747/2012.7597920.bard.
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• Targeted manipulating Phenylalanine (Phe) synthesis is one of the most powerful strategies to boost the biologically and economically important secondary metabolites, including phenylpropaniods, aromatic volatiles and specialized secondary metabolites. • Over-expression of the petunia MYB transcript factor, ODORANT1 (ODO1), results in significant alterations of the levels of specific phenylpropanoid compounds in plants. • Our previous studies indicated that ectopic expression of the feedback-insensitive AroG could break the bottleneck between primary and secondary metabolisms in tomato, thereby aiding in producing new tomato composition and identifying the unknown roles of multiple key regulators in specialized metabolism. Therefore, combining the AroG and ODO1 is of particular interest for elucidating the combined regulatory role of both of these genes in the Phe metabolic pathway, as well as generating tomato fruits that contain higher levels of secondary metabolites. • Here, we performed the LC-MS and GC-MS analyses on fruits of four tomato genotypes, namely, wild type tomato fruits as well as tomato fruits expressing the AroG, ODO1 and the combination of AroG plus ODO1 (AO) genotypes. Our results elaborated that the levels of many of the Phe-derived metabolites were predominately altered in fruits of the AO genotype, compared to tomato fruits expressing either AroG or ODO1 individually. The levels of most of these metabolites were significantly stimulated, such as Tyrosine (Tyr), coumaric acid and ferulic acid derived metabolites, but the levels of some important secondary metabolites were reduced in the AO transgenic genotypes as compared to either AroG or ODO1 lines. Nevertheless, our results also revealed that the levels of aromatic volatiles were obviously down regulated in the AO, compared to that in AroG transgenic fruits, but were boosted while compared to the wild type and ODO1 transgenic fruits. • Our results suggest that ODO1 expression may also have a negative effect on the production of some of the aromatic volatiles in tomato fruits, indicating that ODO1 acts as an important regulator of the shikimate pathway, which leads to the production of the aromatic amino acids and secondary metabolites derived from them. Key words: AroG, ODO1, tomato, metabolism, shikimate pathway
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Aharoni, Asaph, Zhangjun Fei, Efraim Lewinsohn, Arthur Schaffer y Yaakov Tadmor. System Approach to Understanding the Metabolic Diversity in Melon. United States Department of Agriculture, julio de 2013. http://dx.doi.org/10.32747/2013.7593400.bard.
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Fruit quality is determined by numerous genetic factors that affect taste, aroma, color, texture, nutritional value and shelf life. To unravel the genetic components involved in the metabolic pathways behind these traits, the major goal of the project was to identify novel genes that are involved in, or that regulate, these pathways using correlation analysis between genotype, metabolite and gene expression data. The original and specific research objectives were: (1) Collection of replicated fruit from a population of 96 RI lines derived from parents distinguished by great diversity in fruit development and quality phenotypes, (2) Phenotypic and metabolic profiling of mature fruit from all 96 RI lines and their parents, (3) 454 pyrosequencing of cDNA representing mRNA of mature fruit from each line to facilitate gene expression analysis based on relative EST abundance, (4) Development of a database modeled after an existing database developed for tomato introgression lines (ILs) to facilitate online data analysis by members of this project and by researchers around the world. The main functions of the database will be to store and present metabolite and gene expression data so that correlations can be drawn between variation in target traits or metabolites across the RI population members and variation in gene expression to identify candidate genes which may impact phenotypic and chemical traits of interest, (5) Selection of RI lines for segregation and/or hybridization (crosses) analysis to ascertain whether or not genes associated with traits through gene expression/metabolite correlation analysis are indeed contributors to said traits. The overall research strategy was to utilize an available recombinant inbred population of melon (Cucumis melo L.) derived from phenotypically diverse parents and for which over 800 molecular markers have been mapped for the association of metabolic trait and gene expression QTLs. Transcriptomic data were obtained by high throughput sequencing using the Illumina platform instead of the originally planned 454 platform. The change was due to the fast advancement and proven advantages of the Illumina platform, as explained in the first annual scientific report. Metabolic data were collected using both targeted (sugars, organic acids, carotenoids) and non-targeted metabolomics analysis methodologies. Genes whose expression patterns were associated with variation of particular metabolites or fruit quality traits represent candidates for the molecular mechanisms that underlie them. Candidate genes that may encode enzymes catalyzingbiosynthetic steps in the production of volatile compounds of interest, downstream catabolic processes of aromatic amino acids and regulatory genes were selected and are in the process of functional analyses. Several of these are genes represent unanticipated effectors of compound accumulation that could not be identified using traditional approaches. According to the original plan, the Cucurbit Genomics Network (http://www.icugi.org/), developed through an earlier BARD project (IS-3333-02), was expanded to serve as a public portal for the extensive metabolomics and transcriptomic data resulting from the current project. Importantly, this database was also expanded to include genomic and metabolomic resources of all the cucurbit crops, including genomes of cucumber and watermelon, EST collections, genetic maps, metabolite data and additional information. In addition, the database provides tools enabling researchers to identify genes, the expression patterns of which correlate with traits of interest. The project has significantly expanded the existing EST resource for melon and provides new molecular tools for marker-assisted selection. This information will be opened to the public by the end of 2013, upon the first publication describing the transcriptomic and metabolomics resources developed through the project. In addition, well-characterized RI lines are available to enable targeted breeding for genes of interest. Segregation of the RI lines for specific metabolites of interest has been shown, demonstrating the utility in these lines and our new molecular and metabolic data as a basis for selection targeting specific flavor, quality, nutritional and/or defensive compounds. To summarize, all the specific goals of the project have been achieved and in many cases exceeded. Large scale trascriptomic and metabolomic resources have been developed for melon and will soon become available to the community. The usefulness of these has been validated. A number of novel genes involved in fruit ripening have been selected and are currently being functionally analyzed. We thus fully addressed our obligations to the project. In our view, however, the potential value of the project outcomes as ultimately manifested may be far greater than originally anticipated. The resources developed and expanded under this project, and the tools created for using them will enable us, and others, to continue to employ resulting data and discoveries in future studies with benefits both in basic and applied agricultural - scientific research.
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Ibdah, Mwafaq, Dorothea Tholl y Philipp W. Simon. How temperature stress changes carrot flavor: Elucidating the genetic determinants of undesired taste in carrots. United States Department of Agriculture, enero de 2014. http://dx.doi.org/10.32747/2014.7598171.bard.
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Global climate change and warming temperatures represent the greatest future challenge for global food production and quality. In this project, we will define the genetic factors of climate-associated taste deficiencies in carrot. Carrot is considered one of the leading horticultural crops in the world in terms of its nutritional value, health benefits, and unique flavor based on its high content of carotenoids and volatile aroma compounds. In recent years, carrot genotypes of different color with improved nutraceutical attributes have been developed. When exposed to high growth temperatures, carrots develop an undesired harsh and bitter taste caused by the accumulation of terpene metabolites. This taste deficiency represents a quality defect to carrot breeders and large- scale growers and needs to be minimized for successful marketing of carrot crops. Surprisingly, the genetic determinants of bitter and harsh flavor in carrot and their response to temperature stress are not well characterized. We started to elucidate these factors in different carrot cultivars by investigating the biosynthesis of volatile terpenes, which represent the predominant flavor compounds in carrots. Also, up to date we identified and characterized two terpenesynthase enzymes, one of which produces (E)-β- caryophyllene, a major terpene component in carrot root. Both TPSs may contribute to the observed variation in volatile terpene formation.
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Kleman, Isabella. Onion storage diseases and their headspace volatiles. Faculty of Landscape Architecture, Horticulture and Crop Production Science, Swedish University of Agricultural Sciences, 2023. http://dx.doi.org/10.54612/a.602791tdo5.
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Onion, Allium cepa, is one of the world’s most commonly produced and consumed vegetables. In order to be available year round in temperate climates onions must be stored for several months. During this time parts of the harvested weight of bulbs are lost to storage diseases, sprouting and respiration leading to loss of carbohydrates and water. Diseases developing in storage may be difficult to spot at early stages as bulbs are typically stored in large bins. However, storage diseases can change the volatile metabolite profile of the infected onions. Electronic sensors that detect the concentration of specific volatile compounds in the air could be deployed in storage facilities to detect these changes. This would provide an early warning system that could detect diseases developing in storage bins before it becomes obvious to a human observer. In this way, some of the losses that occur during storage of onions could be prevented. This introductory paper discusses some of the available literature on the facets of onion production that are connected to storage disease development and the detection of said storage diseases using headspace sampling and analysis. The focus of the paper is mainly on onion production and storage of long day cultivars in relatively cold, temperate climates, as the use of short day cultivars and warm storage in warmer climates comes with different challenges and diseases.
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Dudareva, Natalia, Alexander Vainstein, Eran Pichersky y David Weiss. Integrating biochemical and genomic approaches to elucidate C6-C2 volatile production: improvement of floral scent and fruit aroma. United States Department of Agriculture, septiembre de 2007. http://dx.doi.org/10.32747/2007.7696514.bard.
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The specific objectives of approved proposal include to: 1. Elucidate the C6-C2 biochemical pathways leading to the biosynthesis of phenylacetaldehyde, phenylethyl alcohol and phenylethyl acetate in floral tissues of ornamentally important plants, pefunia and roses. 2. Isolate and characterrze genes responsible for the production of these C6-C2 compounds and those involved in the regulation of the pathway using genomic and transcriptomic tools. 3. Determine whether altering the expression of key genes of this pathway can result in changing the aroma characteristics of flowers. Aldehydes are intermediates in a variety of biochemical pathways including those involved in the metabolism of carbohydrates, vitamins, steroids, amino acids, benzylisoquinoline alkaloids, hormones, and lipids. In plants they are also synthesized in response to environmental stresses such as salinity, cold, and heat shock or as flavors and aromas in fruits and flowers. Phenylacetaldehyde along with 2-phenylethanol and its acetate ester, are important scent compounds in numerous flowers, including petunias and roses. However, little is known about the biosynthesis of these volatile compounds in plants. We have shown that the formation PHA and 2-phenylethanol from Phe does not occur via trans-cinnamic acid and instead competes with the key enzyme of phenypropanoid metabolism Pheammonia-lyase (PAL) for Phe utilization. Using functional genomic approach and comparative gene expression profiling, we have isolated and characterized a novel enzyme from petunia and rose flowers that catalyzes the formation of the Ca-Czcompound phenylacetaldehyde (PHA) from L-phenylalanine (Phe) by the removal of both the carboxyl and amino groups. This enzyme, designated as phenylacetaldehyde synthases (PAAS), is a bifunctional enzyme that catalyzes the unprecedented efficient coupling of phenylalanine decarboxylation to oxidation, generating phenylacetaldehyde, CO2, ammonia, and hydrogen peroxide in stoichiometric amounts. Down-regulation of PAAS expression via RNA interference-based (RNAi) technology in petunia resulted in no PHA emission when compared with controls. These plants also produced no 2-phenylethanol, supporting our conclusion that PHA is a precursor of 2-phenylethanol. To understand the regulation of scent formation in plants we have also generated transgenic petunia and tobacco plants expressing the rose alcohol acetyltransferase (RhAAT) gene under the control of a CaMV-35S promoter. Although the preferred substrate of RhAAT in vitro is geraniol, in transgenic petunia flowers, it used phenylethyl alcohol and benzyl alcohol to produce the corresponding acetate esters, not generated by control flowers. These results strongly point to the dependence of volatile production on substrate availability. Analysis of the diurnal regulation of scent production in rose flowers revealed that although the daily emission of most scent compounds is synchronized, various independently evolved mechanisms control the production, accumulation and release of different volatiles. This research resulted in a fundamental discovery of biochemical pathway, enzymes and genes involved in biosynthesis of C6-C2s compounds, and provided the knowledge for future engineering plants for improved scent quality.
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Eyal, Yoram, Gloria Moore y Efraim Lewinsohn. Study and Manipulation of the Flavanoid Biosynthetic Pathway in Citrus for Flavor Engineering and Seedless Fruit. United States Department of Agriculture, octubre de 2003. http://dx.doi.org/10.32747/2003.7570547.bard.
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The proposal was aimed to identify and functionally characterize key genes/enzymes in the citrus flavanone neohesperidoside biosynthetic pathway and to use them as tools for metabolic engineering to decrease bitterness levels in grapefruit. The proposed section on fruit seediness was dropped as suggested by the reviewers of the proposal. Citrus flavor and aroma is composed of complex combinations of soluble and volatile compounds. The former includes mainly sugars, acids and flavanones, a subgroup of flavonoids that includes bitter compounds responsible for the bitter flavor of grapefruit and pummelo. Bitter species contain mostly bitter flavanone neohesperidosides, while non-bitter species contain mostly tasteless flavanone rutinosides. Both flavanone versions are diglycosides consisting of a rhamnose-glucose oligosaccharide a-linked at position 7 to the flavanone skeleton. However, in the bitter neohesperidosides the rhamnose is attached at position 2 of the glucose moiety, while in the tasteless rutinosides the rhamnose is attached at position 6 of the glucose moiety. Thus, the position of the rhamnose moiety, determined by the specificity of the last enzymes in the pathway- rhamnosyltransferase (1,2 or 1,6 specificity), is the determinant of the bitter flavor. Flavanones, like all flavonoids are synthesized via one of the branches of the phenylpropanoid pathway; the first committed step is catalyzed by the enzyme Chalcone synthase (CHS) followed by Chalcone isomerase (CHI). During the course of the work a key gene/enzyme in the biosynthesis of the bitter flavanones, a 1,2 rhamnosyltransferase (1,2RT), was functionally characterized using a transgenic cell-culture biotransformation system, confirming that this gene is a prime candidate for metabolic engineering of the pathway. This is the first direct functional evidence for the activity of a plant recombinant rhamnosyltransferase, the first confirmed rhamnosyltransferase gene with 1,2 specificity and the second confirmed rhamnosyltransferase gene altogether in plants. Additional genes of the flavanone pathway that were isolated during this work and are potential tools for metabolic engineering include (I) A putative 1,6 rhamnosyltransferase (1,6RT) from oranges, that is presumed to catalyze the biosynthesis of the tasteless flavanones. This gene is a prime candidate for use in future metabolic engineering for decreased bitterness and is currently being functionally characterized using the biotransformation system developed for characterizing rhamnosyltransferases. (2) A putative 7-0-glucosyltransferase presumed to catalyze the first glycosylation step of the flavanone aglycones. Silencing of gene expression in grapefruit was attempted using three genes: (1) The "upstream" flavonoid biosynthesis genes CHS and CHI, by antisense and co-suppression; and (2) The "downstream" 1,2R T, by an RNAi approach. CHS and CHI silencing resulted in some plants with a dramatically decreased level of the bitter flavanone neohesperidoside naringin in leaves. We have yet to study the long-term effect of silencing these genes on tree physiology, and on the actual bitterness of fruit. The effect of 1,2RT silencing on naringin content in grapefruit has yet to be examined, but a slow growth phenotype for these plants was noted. We speculate that silencing of the final glycosylation step of the flavanones delays their evacuation to the vacuole, resulting in accumulation of flavanones in the cytoplasm, causing inhibitory effects on plant growth. This speculation is yet to be established at the product level. Future metabolic engineering experiments are planned with 1,6RT following functional characterization.