Literatura académica sobre el tema "Triacylglycerol (TAG)"
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Artículos de revistas sobre el tema "Triacylglycerol (TAG)"
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GANGAR, Akanksha, Sumana RAYCHAUDHURI y Ram RAJASEKHARAN. "Alteration in the cytosolic triacylglycerol biosynthetic machinery leads to decreased cell growth and triacylglycerol synthesis in oleaginous yeast". Biochemical Journal 365, n.º 3 (1 de agosto de 2002): 577–89. http://dx.doi.org/10.1042/bj20011654.
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Altered nutrient content (levels of glucose) caused a drastic reduction in cell growth and triacylglycerol (TAG) production in the wild-type (WT) Rhodotorula glutinis. This was due to the decreased level of synthesis of TAG biosynthetic enzymes, reflected by a reduction in enzyme activity. A similar observation was made in the case of non-lethal mutants of TAG-deficient oleaginous yeast, namely TAG1 and TAG2, which were generated by ethyl methane sulphonate mutagenesis. Metabolic labelling of TAG-deficient cells with [14C]acetate, [32P]orthophosphate and [14C]mevalonate showed a negligible TAG formation with minimal alterations in phospholipid and sterol compositions. Assays on the activities of cytosolic TAG biosynthetic enzymes revealed that lysophosphatidic acid and diacylglycerol acyltransferases (ATs) were defective in TAG1 and TAG2 respectively. The activity of membrane-bound isoforms of TAG biosynthetic enzymes remains unaltered in the mutants. Analysis of cytosolic TAG biosynthetic enzymes by immunoblotting and immunoprecipitation indicated that the defective ATs were a part of the TAG biosynthetic multienzyme complex. Quantitatively, the cytosolic lysophosphatidic acid-AT was comparable between TAG1 and the WT. However, diacylglycerol-AT was relatively less in TAG2 than the WT. These results demonstrated that either by decreasing the nutrient content or mutating the enzymes of the soluble TAG biosynthetic pathway, TAG production was decreased with concomitant reduction in the cell growth.
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Roche, Helen M. "Dietary carbohydrates and triacylglycerol metabolism". Proceedings of the Nutrition Society 58, n.º 1 (febrero de 1999): 201–7. http://dx.doi.org/10.1079/pns19990026.
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There is a growing body of scientific evidence which demonstrates that plasma triacylglycerol (TAG) concentration, especially in the postprandial state, is an important risk factor in relation to the development of CHD. Postprandial hypertriacylglycerolaemia is associated with a number of adverse metabolic risk factors, including the preponderance of small dense LDL, low HDL-cholesterol concentrations and elevated factor VII activity. Traditionally, a low-fat high-carbohydrate diet was used to prevent CHD because it effectively reduces plasma cholesterol concentrations, but this dietary regimen increases plasma TAG concentrations and reduces HDL-cholesterol concentrations. There is substantial epidemiological evidence which demonstrates that high plasma TAG and low plasma HDL concentrations are associated with an increased risk of CHD. Thus, there is reason for concern that the adverse effects of low-fat high-carbohydrate diets on TAG and HDL may counteract or negate the beneficial effect of reducing LDL-cholesterol concentrations. Although there have been no prospective studies to investigate whether reduced fat intake has an adverse effect on CHD, there is strong epidemiological evidence that reducing total fat intake is not protective against CHD. On the other hand, high-fat diets predispose to obesity, and central obesity adversely affects TAG metabolism. There is substantial evidence that in free-living situations low-fat high-carbohydrate diets lead to weight loss, which in turn will correct insulin resistance and plasma TAG metabolism. Clearly there is a need for prospective studies to resolve the issue as to whether low-fat high-carbohydrate diets play an adverse or beneficial role in relation to the development of CHD.
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Zárubová, M., V. Filip, J. Šmidrkal, T. Kůtek y I. Piska. "The separation of triacylglycerols using unpolar and medium polar capillary columns". Czech Journal of Food Sciences 22, SI - Chem. Reactions in Foods V (1 de enero de 2004): S123—S126. http://dx.doi.org/10.17221/10633-cjfs.
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Commercial by supplied triacylglycerols and synthesized triacylglycerols were used in this project. Analysed triacylglycerols with the range of carbon number (CN) 24–54 consisted of saturated and unsaturated fatty acids. Two capillary columns were used in the analyses of triacylglycerols, namely non-polar (Optima<sup>®</sup>-1-TG) and medium polar (Optima<sup>®</sup>-17-TG) types. In this study the effectiveness of separation (A) of triacylglycerols with different carbon number values, (B) of triacylglycerols with different unsaturation degree, (C) of positional isomers were determined and further possibilities to separate another lipid compounds were analysed. The column Optima<sup>®</sup>-17-TG separates TAG according to the degree of unsaturation while the column Optima<sup>®</sup>-1-TG separates saturated and unsaturated TAG. High temperature capillary gas chromatography was used to determine changes in triacylglycerol composition during the transesterification of structured fats.
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Whyte, Martin B., Fariba Shojaee-Moradie, Sharaf E. Sharaf, Nicola C. Jackson, Barbara Fielding, Roman Hovorka, Jeewaka Mendis, David Russell-Jones y A. Margot Umpleby. "Lixisenatide Reduces Chylomicron Triacylglycerol by Increased Clearance". Journal of Clinical Endocrinology & Metabolism 104, n.º 2 (11 de septiembre de 2018): 359–68. http://dx.doi.org/10.1210/jc.2018-01176.
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Abstract Context Glucagon-like peptide-1 (GLP-1) agonists control postprandial glucose and lipid excursion in type 2 diabetes; however, the mechanisms are unclear. Objective To determine the mechanisms of postprandial lipid and glucose control with lixisenatide (GLP-1 analog) in type 2 diabetes. Design Randomized, double-blind, cross-over study. Setting Centre for Diabetes, Endocrinology, and Research, Royal Surrey County Hospital, Guildford, United Kingdom. Patients Eight obese men with type 2 diabetes [age, 57.3 ± 1.9 years; body mass index, 30.3 ± 1.0 kg/m2; glycosylated hemoglobin, 66.5 ± 2.6 mmol/mol (8.2% ± 0.3%)]. Interventions Two metabolic studies, 4 weeks after lixisenatide or placebo, with cross-over and repetition of studies. Main Outcome Measures Study one: very-low-density lipoprotein (VLDL) and chylomicron (CM) triacylglycerol (TAG) kinetics were measured with an IV bolus of [2H5]glycerol in a 12-hour study, with hourly feeding. Oral [13C]triolein, in a single meal, labeled enterally derived TAG. Study two: glucose kinetics were measured with [U-13C]glucose in a mixed-meal (plus acetaminophen to measure gastric emptying) and variable IV [6,6-2H2]glucose infusion. Results Study one: CM-TAG (but not VLDL-TAG) pool-size was lower with lixisenatide (P = 0.046). Lixisenatide reduced CM [13C]oleate area under the curve (AUC)60–480min concentration (P = 0.048) and increased CM-TAG clearance, with no effect on CM-TAG production rate. Study two: postprandial glucose and insulin AUC0–240min were reduced with lixisenatide (P = 0.0051; P < 0.05). Total glucose production (P = 0.015), rate of glucose appearance from the meal (P = 0.0098), and acetaminophen AUC0–360min (P = 0.006) were lower with lixisenatide than with placebo. Conclusions Lixisenatide reduced [13C]oleate concentrations, derived from a single meal in CM-TAG and glucose rate of appearance from the meal through delayed gastric emptying. However, day-long CM production, measured with repeated meal feeding, was not reduced by lixisenatide and decreased CM-TAG concentration resulted from increased CM-TAG clearance.
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Gibbons, G. F., D. Wiggins, A. M. Brown y A. M. Hebbachi. "Synthesis and function of hepatic very-low-density lipoprotein". Biochemical Society Transactions 32, n.º 1 (1 de febrero de 2004): 59–64. http://dx.doi.org/10.1042/bst0320059.
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Most of the triacylglycerol (TAG) utilized for the assembly of very-low-density lipoprotein (VLDL) in the secretory apparatus of the hepatocyte is mobilized by lipolysis of the cytosolic TAG pool, followed by re-esterification. The lipases involved include arylacetamide deacetylase and/or triacylglycerol hydrolase. Some of the re-esterified products of lipolysis gain access to an apolipoprotein-B-rich VLDL precursor to form mature VLDL. Some, however, are returned to the cytosolic pool in a process that is stimulated by insulin and inhibited by microsomal triacylglycerol transfer protein (MTP). Phospholipids also contribute to VLDL TAG in a process which involves ADP-ribosylation factor-1 (ARF-1)-mediated activation of phospholipase D. The temporary storage of TAG in the liver, followed by its mobilization and secretion as VLDL, form part of a process by which the liver protects vulnerable body tissues from excess lipotoxic non-esterified (‘free’) fatty acids in the plasma.
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Razul, M. Shajahan G., Colin J. MacDougall, Charles B. Hanna, Alejandro G. Marangoni, Fernanda Peyronel, Erzsebet Papp-Szabo y David A. Pink. "Oil binding capacities of triacylglycerol crystalline nanoplatelets: nanoscale models of tristearin solids in liquid triolein". Food Funct. 5, n.º 10 (2014): 2501–8. http://dx.doi.org/10.1039/c3fo60654f.
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Lu, Junhao, Yang Xu, Juli Wang, Stacy D. Singer y Guanqun Chen. "The Role of Triacylglycerol in Plant Stress Response". Plants 9, n.º 4 (8 de abril de 2020): 472. http://dx.doi.org/10.3390/plants9040472.
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Vegetable oil is mainly composed of triacylglycerol (TAG), a storage lipid that serves as a major commodity for food and industrial purposes, as well as an alternative biofuel source. While TAG is typically not produced at significant levels in vegetative tissues, emerging evidence suggests that its accumulation in such tissues may provide one mechanism by which plants cope with abiotic stress. Different types of abiotic stress induce lipid remodeling through the action of specific lipases, which results in various alterations in membrane lipid composition. This response induces the formation of toxic lipid intermediates that cause membrane damage or cell death. However, increased levels of TAG under stress conditions are believed to function, at least in part, as a means of sequestering these toxic lipid intermediates. Moreover, the lipid droplets (LDs) in which TAG is enclosed also function as a subcellular factory to provide binding sites and substrates for the biosynthesis of bioactive compounds that protect against insects and fungi. Though our knowledge concerning the role of TAG in stress tolerance is expanding, many gaps in our understanding of the mechanisms driving these processes are still evident. In this review, we highlight progress that has been made to decipher the role of TAG in plant stress response, and we discuss possible ways in which this information could be utilized to improve crops in the future.
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Menon, Jesudas E., David J. Stensel, Keith Tolfrey y Stephen F. Burns. "Increased Meal Frequency With Exercise Mitigates Postprandial Triacylglycerol". Journal of Physical Activity and Health 16, n.º 8 (1 de agosto de 2019): 589–94. http://dx.doi.org/10.1123/jpah.2018-0696.
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Purpose: This study examined how manipulating meal frequency, with and without exercise, affects postprandial triacylglycerol (TAG). Methods: Fourteen sedentary men completed four 2-day trials in a noncounterbalanced random cross-over order: (1) consumption of 1 large high-fat milkshake without exercise (1-CON), (2) consumption of 2 smaller high-fat milkshakes without exercise (2-CON), (3) consumption of 1 large high-fat milkshake with exercise (1-EX), and (4) consumption of 2 small high-fat milkshakes with exercise (2-EX)—total energy intake was standardized across trials. On day 1, participants rested (1-CON and 2-CON) or walked briskly for 60 minutes (1-EX and 2-EX). On day 2, participants consumed either a single large high-fat milkshake (75% fat; 1-CON and 1-EX) for breakfast or 2 smaller isoenergetic milkshakes (2-CON and 2-EX) for breakfast and lunch. Plasma TAG were measured fasting and for 7 hours after breakfast. Results: Peak incremental TAG was 30% lower on 2-EX than 1-CON (P = .04, d = 0.38). Postprandial TAG increased more rapidly in the first 4 hours in 1-CON than other trials; but at 6 hours, TAG was exaggerated in 2-CON compared with 1-CON. Conclusions: Increasing meal frequency after exercise, without altering overall fat intake, attenuates postprandial TAG.
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Lee, Ju-Young, Kwang-Hyeon Liu, Yunhi Cho y Kun-Pyo Kim. "Enhanced Triacylglycerol Content and Gene Expression for Triacylglycerol Metabolism, Acyl-Ceramide Synthesis, and Corneocyte Lipid Formation in the Epidermis of Borage Oil Fed Guinea Pigs". Nutrients 11, n.º 11 (18 de noviembre de 2019): 2818. http://dx.doi.org/10.3390/nu11112818.
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Triacylglycerol (TAG) metabolism is related to the acyl-ceramide (Cer) synthesis and corneocyte lipid envelope (CLE) formation involved in maintaining the epidermal barrier. Prompted by the recovery of a disrupted epidermal barrier with dietary borage oil (BO: 40.9% linoleic acid (LNA) and 24.0% γ-linolenic acid (GLA)) in essential fatty acid (EFA) deficiency, lipidomic and transcriptome analyses and subsequent quantitative RT-PCR were performed to determine the effects of borage oil (BO) on TAG content and species, and the gene expression related to overall lipid metabolism. Dietary BO for 2 weeks in EFA-deficient guinea pigs increased the total TAG content, including the TAG species esterified LNA, GLA, and their C20 metabolized fatty acids. Moreover, the expression levels of genes in the monoacylglycerol and glycerol-3-phosphate pathways, two major pathways of TAG synthesis, increased, along with those of TAG lipase, acyl-Cer synthesis, and CLE formation. Dietary BO enhanced TAG content, the gene expression of TAG metabolism, acyl-Cer synthesis, and CLE formation.
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Cossignani, L., D. Montesano, M. S. Simonetti y F. Blasi. "Authentication ofCoffea arabicaaccording to Triacylglycerol Stereospecific Composition". Journal of Analytical Methods in Chemistry 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/7482620.
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Stereospecific analysis is an important tool for the characterization of lipid fraction of food products. In the present research, an approach to characterizearabicaandrobustavarieties by structural analysis of the triacylglycerol (TAG) fraction is reported. The lipids were Soxhlet extracted from ground roasted coffee beans with petroleum ether, and the fatty acids (FA) were determined as their corresponding methyl esters. The results of a chemical-enzymatic-chromatographic method were elaborated by a chemometric procedure, Linear Discriminant Analysis (LDA). According to the total and intrapositional FA composition of TAG fraction, the obtained results were able to characterize roasted pure coffee samples and coffee mixtures with 10%robustacoffee added toarabicacoffee. Totally correct classified samples were obtained when the TAG stereospecific results of the considered coffee mixture (90 : 10arabica/robusta) were elaborated by LDA procedure.
Tesis sobre el tema "Triacylglycerol (TAG)"
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Zallot, Rémi. "Identification et caractérisation d'une lipase exprimée pendant l'hydrolyse des réserves chez Arabidopsis thaliana". Thesis, Bordeaux 2, 2011. http://www.theses.fr/2011BOR21840/document.
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Les réserves d’huile de la graine d’Arabidopsis thaliana sont hydrolysées par des lipases au cours de la croissance post-germinative de la plantule. Une protéine capable de fixer un inhibiteur de lipase a été identifiée à partir d’un extrait de plantules de colza. La séquence de cette protéine ressemble à celles de lipases connues. L’expression transitoire du gène orthologue d’Arabidopsis chez Nicotiana benthamiana induit l’apparition d’une activité lipase. Ces données suggèrent que cette protéine est une lipase. Une étude de la localisation in vivo de cette enzyme chez Nicotiana benthamiana indique qu’elle est localisée au niveau des peroxysomes. Chez Arabidopsis, le gène codant pour cette lipase est exprimé essentiellement lors de la croissance des plantules, quand l’hydrolyse de l’huile est maximale. L’analyse d’un mutant montre que ce gène est responsable de l’essentiel de l’activité lipase mesurée pendant la mobilisation de l’huile de réserve. Ces données suggèrent que cette lipase pourrait être impliquée dans la mobilisation des réserves lipidiques pendant la croissance post-germinative. Néanmoins, l’hydrolyse des réserves n’est pas diminuée chez le mutant. Cela pourrait être lié à une compensation par d’autres lipasesIn germinating seedlings of Arabidopsis thaliana, fat storage breakdown is initiated by lipases. A protein capable to bind to a lipase inhibitor was identified from an extract of rape seedlings and its amino acid sequence found to resemble that of known lipases. Transient expression of the Arabidopsis orthologous gene led to a 100-fold increase in lipase activity in Nicotiana bethamiana leaves. Taken together, these data strongly suggest that this protein is indeed a lipase. In vivo localization studies using a GFP fusion protein in Nicotiana benthamiana as a transcient expression host showed a peroxisomal localization. In Arabidopsis, the gene coding for this lipase was found to be mainly expressed in seedlings during fat storage breakdown. Most lipase activity was abolished in germinating seedlings of an Arabidopsis mutant for this gene. These data suggest that this lipase is likely involved in the breakdown of fat storage in germinating seedlings of Arabidopsis. However, oil mobilization was not affected in Arabidopsis mutant plants. This might suggest that the effect of the mutation could be compensated for by other lipases
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Rahman, Md Mahbubur. "Characterization of Acyltransferases and WRINKLED Orthologs Involved in TAG Biosynthesis in Avocado". Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3519.
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Triacylglycerols (TAG) or storage oils in plants are utilized by humans for nutrition, production of biomaterials and fuels. Since nonseed tissues comprise the bulk biomass, it is pertinent to understand how to improve their TAG content. Typically, the final step in TAG biosynthesis is catalyzed by diacylglycerol (DAG) acyltransferases (DGAT) and/or phospholipid: diacylglycerol acyltransferases (PDAT), which also determine the content and composition of TAG. Besides enzymatic regulation of TAG synthesis, transcription factors such as WRINKLED1 (WRI1) play a critical role during fatty acid synthesis. In this study, mesocarp of Persea americana, with > 60% TAG by dry weight and oleic acid as the major constituent was used as a model system to explore TAG synthesis in nonseed tissues. Based on the transcriptome data of avocado, it was hypothesized that both DGAT and PDAT are likely to catalyze the conversion of DAG to TAG, and orthologs of WRI1 transcription factors regulate fatty acid biosynthesis. Here, with comprehensive in silico analyses, putative PamDGAT1 and 2 (Pam; Persea americana), PamPDAT1, and PamWRI1 and 2 were identified. When acyltransferases were expressed into TAG-deficient mutant yeast strain (H1246), only DGAT1 restored TAG synthesis capacity, with a preference for oleic acid. However, in planta, when transiently expressed in Nicotiana benthamiana leaves, PamDGAT1, PamPDAT1, PamWRI1, and PamWRI2 increased lipid contents, PamDGAT2 remained inactive. The data reveals that putative PamDGAT1, PamPDAT1 are functional and preferred acyltransferases in avocado and both PamWRI1 and 2 regulate fatty acid synthesis. In conclusion, while nonseed tissue of a basal angiosperm has certain distinct regulatory features, DAG to TAG conversion remains highly conserved.
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Millán, Oropeza Aarón. "Comparative study of the proteome of S. coelicolor M145 and S. lividans TK24, two phylogenetically closely related strains with very different abilities to accumulate TAG and produce antibiotics". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS160/document.
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Les Streptomyces sont des bactéries filamenteuses du sol à Gram +. Elles sont connues pour leur capacité à produire des métabolites secondaires utiles en médecine et en agriculture. S. coelicolor et S. lividans sont des souches modèles phylogénétiquement proches. Elles ont cependant des capacités contrastées à accumuler des lipides de réserve de la famille des triacylglycérol (TAG) et produire des métabolites secondaires alors qu’elles possèdent des voies de biosynthèse similaires pour ces deux types de molécules. En présence de glucose, S. coelicolor produit des niveaux élevés de métabolites secondaires spécifiques et son contenu en TAG est faible alors que c'est le contraire chez S. lividans. En revanche, en présence de glycérol, les deux souches accumulent une quantité de TAG similaire mais S. coelicolor produit aussi des métabolites secondaires. Le but de la présente thèse était de déterminer les caractéristiques métaboliques différentielles qui sous-tendent les différentes capacités biosynthétiques de ces deux souches modèles. Pour ce faire, une analyse protéomique comparative sans marquage des souches cultivées en milieu R2YE liquide ou solide en présence de glucose ou de glycérol comme principales sources de carbone a été réalisée en utilisant la technique de chromatographie liquide couplée à de la Spectrométrie de Masse en tandem (LC-MS / MS). Au total, 2024 et 4372 protéines ont été identifiées à partir des cultures liquides et solides, représentant 24% et 50% du protéome théorique. Les études en liquide ont révélé que le métabolisme de S. lividans était principalement glycolytique alors que le métabolisme de S. coelicolor était principalement oxydatif. Elles ont également indiqué que ces caractéristiques pourraient être liées au catabolisme préférentiel des acides aminés par rapport au glucose chez S. coelicolor par rapport à S. lividans. De plus, cette thèse constitue la première analyse protéomique du métabolisme de ces deux souches modèles en présence de glycérolStreptomyces are filamentous Gram+ soil bacteria well known for their ability to produce secondary metabolites useful in medicine and agriculture. S. coelicolor and S. lividans are phylogenetically closely-related model strains but they have contrasted abilities to accumulate storage lipids of the TriAcylGlycerol (TAG) family and to produce secondary metabolites whereas they possess similar pathways for the biosynthesis of these molecules. In the presence of glucose, S. coelicolor produces high levels of specific secondary metabolites and its TAG content is low whereas it is the opposite for S. lividans. In contrast, in the presence of glycerol, the two strains accumulated similar amount of TAG but S. coelicolor still produces secondary metabolites. The aim of the present thesis was to determine the differential metabolic features supporting such different biosynthetic abilities. To do so, a comparative label-free shotgun proteomic analysis of the strains grown in liquid or solid R2YE media with glucose or glycerol as main carbon sources was carried out using Liquid chromatography−tandem mass spectrometry (LC−MS/MS). A total of 2024 and 4372 proteins were identified in liquid and solid cultures, representing 24% and 50% of the theoretical proteome, respectively. These studies revealed that S. lividans metabolism was mainly glycolytic whereas S. coelicolor metabolism was mainly oxidative. They also suggested that these features might be related to the preferential catabolism of amino acids over glucose of S. coelicolor compared to S. lividans. Furthermore, this thesis constituted the first proteomic analysis of the metabolism of these two model strains in the presence of glycerol
Streptomyces es un género de bacterias filamentosas Gram+ provenientes del suelo que son conocidas por su capacidad para producir metabolitos secundarios útiles en la medicina y agricultura. S. coelicolor y S. lividans son cepas modelo filogenéticamente próximas que presentan capacidades opuestas para acumular lípidos de reserva de la familia de los triglicéridos (TAG) y para producir metabolitos secundarios en tanto que ambas cepas poseen rutas metabólicas idénticas para la biosíntesis de éstas moléculas. En presencia de glucosa, S. coelicolor produce altos niveles de metabolitos secundarios específicos y su contenido de TAG es bajo mientras que en S. lividans el comportamiento es opuesto. Sin embargo, en presencia de glicerol, ambas cepas acumulan cantidades similares de TAG y S. coelicolor produce metabolitos secundarios. El objetivo de ésta tesis fue de determinar las características metabólicas que distinguen las diferentes capacidades biosintéticas mencionadas previamente. Por esto, un análisis protéomico comparativo sin marcaje de tipo “shotgun” fue realizado con las dos cepas cultivadas en medio R2YE líquido y sólido usando glucosa o glicerol como fuentes principales de carbono mediante Cromatografía Líquida en “tándem” acoplada a Espectrometría de Masas (LC-MS/MS). Un total de 2024 y 4372 proteínas fueron identificadas en cultivos en medio líquido y sólido, representando 24% y 50% del proteoma teórico, respectivamente. El presente estudio demostró que el metabolismo de S. lividans fue principalmente glicolítico mientras que el metabolismo de S. coelicolor fue principalmente oxidativo. También se sugiere que éstas características pueden estar relacionadas con la preferencia catabólica de aminoácidos sobre el catabolismo de glucosa de S. coelicolor comparada con S. lividans. Además, la presente tesis constituye el primer análisis proteómico del metabolismo de éstas dos cepas modelo en presencia de glicerol
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Hizbai, Biniam T. "Comparative Mapping of QTLs Affecting Oil Content, Oil Composition, and other Agronomically Important Traits in Oat (Avena sativa L.)". Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23481.
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Groat oil content and composition are important quality traits in oats (Avena sativa L). These traits are controlled by many genes with additive effects. The chromosomal regions containing these genes, known as quantitative trait loci (QTL), can be discovered through their close association with markers. This study investigated total oil content and fatty acid components in an oat breeding population derived from a cross between high oil ('Dal') and low oil ('Exeter') parents. A genetic map consisting of 475 DArT (Diversity Array Technology) markers spanning 1271.8 cM across 40 linkage groups was constructed. QTL analysis for groat oil content and composition was conducted using grain samples grown at Aberdeen, ID in 1997. QTL analysis for multiple agronomic traits was also conducted using data collected from hill plots and field plots in Ottawa, ON in 2010. QTLs for oil content, palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) were identified. Two of the QTLs associated with oil content were also associated with all of the fatty acids examined in this study, and most oil-related QTL showed similar patterns of effect on the fatty acid profile. These results suggest the presence of pleiotropic effects on oil-related traits through influences at specific nodes of the oil synthesis pathway. In addition, 12 QTL-associated markers (likely representing nine unique regions) were associated with plant height, heading date, lodging, and protein content. The results of this study will provide information for molecular breeding as well as insight into the genetic mechanisms controlling oil biosynthesis in oat.
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Perry, James. "FIELD EVALUATION OF TOBACCO ENGINEERED FOR HIGH LEAF-OIL ACCUMULATION". UKnowledge, 2019. https://uknowledge.uky.edu/pss_etds/118.
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The biofuel market is dominated by ethanol and biodiesel derived from cellulosic and lipid-based biomass crops. This is largely due to the relatively low costs and reliability of production. At present, production of non-food plant-derived oils for biofuel production in the U.S. is minimal. A research team from the Commonwealth Scientific and Industrial Research Organization (CSIRO), an independent Australian federal government research institution, has developed an efficient transgenic system to engineer oil production in tobacco leaves. This novel system is comprised of multiple transgenes that direct the endogenous metabolic flux of oil precursors towards triacylglycerol (TAG) production. Additional genes were incorporated to store and protect the accumulated oil in vegetative tissues. Preliminary greenhouse tests by the CSIRO research group indicated an oil content of > 30% by dry weight (DW) in tobacco leaf lamina. Here we evaluated two transgenic lines against a non-transgenic control in 2017 and 2018 in greenhouse and field production systems. The 2017 pilot study showed that the high leaf-oil tobacco line was viable and will grow in the field in Kentucky. Chemical analyses revealed significantly higher oil content compared to the non-transgenic control despite several logistical setbacks. These promising discoveries prompted the deployment of additional transgenic line assessments and further data validation in 2018. Line evaluations in 2018 revealed that the LEC2:WRI1:DGAT:OLE transgenic line had the highest leaf oil content (≥ 19.3% DW-1) compared to both the WRI1:DGAT:OLE transgenic line (≤ 5.6% DW-1) and non-transgenic control (≤ 2.1% DW-1). The results of this research will contribute to the successful development of transgenic tobacco lines engineered to accumulate high concentrations of TAG in the leaves.
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Miller, Neidi. "Process design and modeling for the production of triacylglycerols (TAGs) in Rhodococcus opacus PD630". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70461.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012."February 2012." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 32-34).
The oleaginous microorganism Rhodococcus opacus PD630 was used to study the characteristics and kinetics of the accumulation of triacylglycerols (TAGs) in cells. In this process, accumulation of TAG is stimulated when a carbon source is present in the medium in excess and the nitrogen source is limiting growth. Under controlled fermentation conditions the organism Rhodococcus opacus PD630 has been shown to grow to high cell density, producing high yields of TAGs (above 50% of cell dry weight) in a relatively short period of time. In this study, the reaction stoichiometry was established and the carbon balance for the process has been effectively closed, accounting for approximately 91% of the total carbon in the system. Several fed-batch strategies were explored at the IL benchtop bioreactor scale. Feeding both carbon and ammonium sulfate as the nitrogen source can sustain cell growth but was found to significantly obstruct the accumulation of TAGs. While these fed-batch strategies did not lead to titer improvements, they did highlight the significance of TAG degradation for growth. To aid in future process design strategy optimization an unstructured kinetic model was developed to describe the dynamics of the fermentation of Rhodococcus opacus PD630 and its triacylglycerol (TAG) production. The kinetic parameters for this model were either measured from experimental data or estimated by fitting the experimental data using least-squares non-linear regression. Global minimum of the sum of squared errors (SSE) between the model prediction and various experimental data sets was found by an iterative process of parameter space exploration. The minimum SSE obtained was 91.229. The proposed model is the first step towards understanding and optimizing the process of lipid production and accumulation in oleaginous organisms.
by Neidi Miller.
S.M.
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Degraeve, Guilbault Charlotte. "Caractérisation des glycérolipides et de la dynamique de remodelage en chaines acyles chez Ostreococcus tauri". Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0825/document.
Texto completoResumen
La picoalgue verte marine Ostreococcus tauri est un eucaryote minimal développé en système modèle et qui a servi de ressource de gènes en biologie des lipides. Des informations détaillées sur ces caractéristiques lipidiques étaient cependant manquantes. Lors de ma thèse j’ai caractérisé le glycérolipidome d’O. tauri et ai cherché à déterminer quelles sont les cibles enzymatiques responsables de la dynamique des acides gras (FA) et de la régulation du métabolisme lipidique en réponse à des modifications de l’environnement (carences nutritives et refroidissement). O. tauri présente des caractéristiques uniques de composition en lipides et en FA mixtes entre les algues vertes et les Chromalveolates, et a été validé comme espèce modèle pour la classe des Mamiellophyceae. L’acide docosahexaénoïque (DHA) est confiné dans les lipides présumés extraplastidiaux : le phosphatidyldimethylpropanethiol (PDPT) et le bétaïne-lipide diacylglyceryl-hydroxymethyl-trimethyl-β-alanine (DGTA), tous deux marqueurs lipidiques des Chromalveolates. Les lipides plastidiaux de type procaryotique sont caractérisés par une prépondérance de FA polyinsaturés (PUFA) en C18 n-3, le 18:5 n-3 étant restreint aux galactolipides. Le 16:4 n-3, PUFA typique des galactolipides des microalgues vertes, est également un composant majoritaire des lipides extraplastidiaux chez O. tauri. Les triacylglycérols (TAG) présentent tout le panel d’acides gras d’O. tauri et leurs combinaisons moléculaires indiquent une origine plastidiale majoritaire. La carence azote provoque une forte accumulation de TAG, notamment des espèces présentant des combinaisons sn-1/sn-2 en 18:X/16:X et s'accompagne d'un transfert de carbone du phosphatidylglycérol (PG) et du monogalactosyldiacylglycérol (MGDG) aux TAG ce qui indique une contribution croissante de la voie plastidiale à la synthèse des TAG. Des expériences préliminaires de RT-qPCR sur des gènes du métabolisme des TAG révèlent une forte activation transcriptionnelle de certaines diacylglycérol acyltransférases (DAGT). Les carences nutritives répriment sévèrement l’activité Δ6 désaturase, générant une inversion du ratio 18:3/18:4 dans les lipides plastidiaux qui se répercute dans les TAG. La régulation fine et dynamique de ce ratio suggère un rôle important du 18:3 et du 18:4 dans les membranes plastidiales. Le refroidissement engendre une augmentation spécifique du 18:5 des galactolipides. La recherche active de la désaturase responsable de ce phénotype par une approche d'expression de gènes candidats en systèmes homologue et hétérologues (S. cerevisiae, N. Benthamiana) a conduit à l’indentification de deux Δ6 désaturases plastidiales jamais caractérisées dans d'autres systèmes. Celles-ci possèdent des spécificités non redondantes et originales entre elles et par rapport à l'acyl-CoA-Δ6 d'O. tauriThe marine green picoalga Ostreococcus tauri is a minimal eukaryote implemented as model system that has been used as gene resource for lipid biology. Detailed information about its lipidic features was however missing. During my PhD, I characterized O. tauri glycerolipidome and associated dynamics under environmental stresses such as nutrient starvations and chilling and investigated transcriptional variations of putative target enzymes responsible for these changes. O. tauri which could be validated as model for related species of the class Mamiellophyceae, was found to display unique lipidic features related to both green and Chromalveolates microalgae. Docosahexaenoic acid (DHA) is confined to presumed extraplastidial lipids i.e. phosphatidyldimethylpropanethiol (PDPT) and the betaine lipid diacylglyceryl-hydroxymethyl-trimethyl-β-alanine (DGTA); all of these compounds are hallmarks of Chromalveolates. Plastidial lipids found to be of prokaryotic type are characterized by the overwhelming presence of C18 n-3 polyunsaturated FA (PUFA), 18:5 n-3 being restricted to galactolipids. C16:4 n-3, an FA typical of green microalgae galactolipids, also was a major component of O. tauri extraplastidial lipids. Triacylglycerols (TAGs) display the complete panel of FAs, and their molecular combinations designate a major plastidial origin of DAG precursors. Nitrate starvation greatly increases TAG content, in particular 18:X/16:X (sn-1/sn-2) combinations, and was associated with the transfer of carbon from phosphatidylglycerol (PG) and monogalactosyldiacylglycerol (MGDG) to TAG indicating an increased contribution of the plastidial pathway to the TAG synthesis. Preliminary RT-qPCR experiments on TAG metabolism genes revealed an important transcriptional activation of some diacylglycerol acyltransferases (DGAT). Nutrient starvations severely repress Δ6 desaturase activity and result in the inversion of the 18:3/18:4 ratio in plastidial lipids that was feedback into TAG. The fine-tuning and dynamic regulation of the 18:3/18:4 ratio suggests an important physiological role of these FAs in photosynthetic membranes. Chilling generates an increase of 18:5 in galactolipids. The active quest for the desaturases responsible for this phenotype was achieved by expressing candidate genes in homologuous and heterologous (S. cerevisiae, N. Benthamiana) systems and led to the identification of two yet uncharacterized plastidial Δ6 desaturases. These desaturases display original and non-redundant specificity between each other and with the previously characterized in O. tauri Δ6 acyl-CoA desaturase
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Parthibane, V. "Oleosin, a Bifunctional Enzyme is Phosphoregulated by a Protein Kinase". Thesis, 2012. https://etd.iisc.ac.in/handle/2005/4583.
Texto completoResumen
In eukaryotic cells, lipids are indispensable principal components that vitiate biological
life. Lipids are classified into two major groups, polar and non-polar lipids. Polar lipids
are phospholipids, whereas non-polar lipids have broad classes such as sterols neutral
storage lipids, sphingolipids and glycolipids. Lipids can further be classified into two
major classes, functional lipids and non functional lipids. Functional lipids include
phospholipids that form the biological membrane bilayer giving protection to the cell
from various external stresses. Another molecule, the diacylglycerol acts as signaling
molecule for various signal transduction pathways involved in gene expression or
biological responses. Non-functional lipids, like triacylglycerol and steryl esters are
stored lipids and are retrieved upon energy crisis conditions in eukaryotic cells
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McNaughton, Amy J. M. "Evaluation of Genes Encoding the Enzymes of the Kennedy Pathway in Soybeans with Altered Fatty Acid Profiles". Thesis, 2012. http://hdl.handle.net/10214/3760.
Texto completoResumen
Soybean (Glycine max (L.) Merr) is the largest oil and protein crop in the world and it is grown for both oil and protein. To address the needs of both the edible oil market and industrial applications of soybean oil, fatty acid modification has been a focus of soybean breeding programs. Natural variation, mutagenesis and genetic engineering have been used to alter the fatty acid profile. Several genes, mostly desaturases, have been associated with altered fatty acid profiles but enzymes in the Kennedy Pathway have yet to be studied as another source of genetic variation for altering the fatty acid profiles. The Kennedy Pathway is also known as the oil producing pathway and consists of four enzymes: glycerol-3-phosphate acyltransferase (G3PAT); lysophosphatidic acid acyltransferase (LPAAT); phosphatidic acid phosphatase (PAP); and diacylglycerol acyltransferase 1 (DGAT1). The starting material for this pathway is glycerol-3-phosphate, which is produced from glycerol by glycerol kinase (GK), and the product of this pathway is triacylglycerol (TAG). The overall objective of this study was to elucidate the role that the Kennedy Pathway plays in determining the fatty acid profile in two ways: (1) sequencing the transcribed region of the genomic genes encoding the enzymes of GK, G3PAT, LPAAT, and DGAT1 in soybean genotypes with altered fatty acid profiles; and (2) studying their expression over seed development, across three growing temperatures. The genetic material for the study consisted of four soybean genotypes with altered fatty acid profile: RG2, RG7, RG10, and SV64-53. Results from sequencing showed that the mutations identified in G3PAT, LPAAT, and DGAT1 in the four soybean genotypes did not explain the differences in the fatty acid profiles. The expression of G3PAT, LPAAT, and DGAT1 over seed development showed that G3PAT had the lowest levels, followed by LPAAT, then DGAT1, across the growing temperatures. The differences in expression among genotypes corresponded to differences in fatty acid accumulation, suggesting that expression rather than genetic mutations in the transcribed region of the genes influenced the fatty acid profile of the genotypes in this study. In conclusion, the enzymes of the Kennedy Pathway appear to contribute to the altered fatty acid profiles observed in the soybean mutant genotypes.Ontario Ministry of Economic Development and Innovation (formerly Ontario Ministry of Research and Innovation), BioCar Initiative, Grain Farmers of Ontario, SeCan
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Alkotami, Linah. "Enhancing the production of acetyl-triacylglycerols through metabolic engineering of the oilseed crop Camelina sativa". Thesis, 2018. http://hdl.handle.net/2097/39300.
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Master of ScienceBiochemistry and Molecular Biophysics Interdepartmental Program
Timothy P. Durrett
Many Euonymus species express an acetyltransferase enzyme in their seeds which catalyzes the transfer of an acetyl group from acetyl-CoA to the sn-3 position of diacylglycerol (DAG) producing unusual acetyl-1,2-diacyl-sn-glycerols (acetyl-TAG). The presence of the sn-3 acetate group gives acetyl-TAG with unique physical properties over regular triacylglycerol (TAG) found in vegetable oils. The useful characteristics of acetyl-TAG oil offer advantages for its use as emulsifiers, lubricants, and 'drop-in' biofuels. One enzyme, Euonymus alatus diacylglycerol acetyltransferase (EaDAcT), responsible for acetyl-TAG synthesis in nature was previously isolated from the seeds of Euonymus alatus (burning bush) and expressed in the oilseed crop Camelina sativa. Expression of EaDAcT successfully led to production of high levels of acetyl-TAG in camelina seeds. To further increase acetyl-TAG accumulation in transgenic camelina seeds, multiple strategies were examined in this study. Expression of a new acetyltransferase enzyme (EfDAcT) isolated from the seeds of Euonymus fortunei, which was previously shown to possess higher in vitro activity and in vivo acetyl-TAG levels compared to EaDAcT, increased acetyl-TAG accumulation by 20 mol%. Suppression of the endogenous competing enzyme DGAT1 further enhanced acetyl-TAG accumulation to 90 mol% in selected transgenic line. Studying the regulation of EfDAcT transcript, protein, and acetyl-TAG levels during seed development further provided new insights on the factors limiting acetyl-TAG accumulation.
Capítulos de libros sobre el tema "Triacylglycerol (TAG)"
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Gogoi, Javin. "Estimation of Serum Triglycerides (TG) or Triacylglycerol (TAG)". En Simplified Practical Manual of Biochemistry, 115. Jaypee Brothers Medical Publishers (P) Ltd., 2015. http://dx.doi.org/10.5005/jp/books/12488_30.
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O'sullivan, Chloe, Nuria Acevedo, Fernanda Peyronel y Alejandro G. Marangoni. "Fat Nanostructure". En Edible Nanostructures, 6–40. The Royal Society of Chemistry, 2014. http://dx.doi.org/10.1039/bk9781849738958-00006.
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Fat is made up of a mixture of triacylglycerol molecules (TAGs) – three fatty acids esterified to a glycerol backbone. The solid material is structured by a fraction of high melting point TAGs, which form a crystal network that traps the low melting TAGs within. Characterization of that crystal network is an important tool to understand fat properties and functionality. This chapter will cover fat crystal structure using a bottom-up approach, from TAG molecules to space-filling network. Emphasis will be on the fat crystal nanoscale, a level which was recently isolated and characterized, and how nano-sized crystalline structures fit into the larger network. Finally, the effect of composition and crystallization conditions on crystal structure and bulk physicochemical properties will be examined, to understand how processing conditions can be used to target functionality.
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Nazir, Yusuf, Pranesha Prabakaran, Tahira Naz, Hassan Mohamed, Shaista Nosheen, Abu Bakr Ahmad Fazili, Aidil Abdul Hamid y Yuanda Song. "Acylglycerols in Fungi". En Fungal Lipid Biochemistry, 106–22. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815123012123010008.
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Over the past decades, fungi have been increasingly recognized as the potential source of lipids that can be applied in various sectors, including nutraceutical and biofuel. Thus, many studies have been conducted to understand the structural and functional roles of lipid molecules, particularly in the potential oleaginous strains. Lipids produced by oleaginous fungi comprise different classes, and acylglycerol, which are esters formed from different fatty acids and alcohols such as glycerol, represent the major components of the lipid. The biosynthesis of acylglycerol in fungi involved a series of reactions involving the central carbon and glycerol-3-phosphate (G-3-P), while its catabolism in vivo generally involved the degradation of triacylglycerol (TAG) by intracellular lipase resulting in the release of fatty acids and glycerol. The resulting glycerol will be phosphorylated, oxygenated, and enter glycolysis, whereas the fatty acids will undergo β-oxidation into acetyl-CoA and be used for various physiological functions. On the other hand, several fungi species, particularly from the Mucoralles sp, have been documented to be able to utilize the oil and fat as the alternative substrate for growth and reproduction due to its capability to produce extracellular lipases which hydrolyze the ester bond of the TAG. This chapter will comprehensively discuss the functional role of acylglycerol in fungi, its biosynthesis, as well as in vivo and ex vivo degradation in fungi, which will be a bridge toward the development of the industrial application.
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"28 Abbau von Triacylglycerinen und Ketonkörpern Triacylglycerin (TAG) Ketonkörper". En Biochemie für die Tiermedizin, editado por Wilfried A. Kues y Maren von Köckritz-Blickwede. Stuttgart: Georg Thieme Verlag KG, 2021. http://dx.doi.org/10.1055/b-0040-179429.
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Kolpe, Sakshi, Shankar Mukundrao Khade y Shivraj Nile. "Macroalgae-Based Bioethanol". En Biomass and Bioenergy Solutions for Climate Change Mitigation and Sustainability, 206–16. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-5269-1.ch012.
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The chapter discusses the methods effective for the extraction of useful energy from the macroalgae biomass including liquefaction, anaerobic digestion, fermentation to biobutanol, trans-esterification to biodiesel, pyrolysis, direct combustion, fermentation to bioethanol, and gasification. However, if the algae are suited for the production of biodiesel, they can be studied from the content of their triacylglycerols (TAGs). Due to having high fatty acid content, they have a high conversion rate to biodiesel, and the lack of sulphur, phosphorus, and nitrogen also aids in the conversion. This chapter highlights the limitations and suitability of macroalgae for the conversion process in reference to chemical composition, process optimization, and cost effectiveness. It is concluded that bio-oils and bioethanol produced from wet macroalgae are considered over biodiesel production because of high lipid content of microalgae biomass. Moreover, the chapter considers electricity production from the dry mass as it would turn profitable, and this can be achieved from fast-growing macroalgae like “Ulva.”
Actas de conferencias sobre el tema "Triacylglycerol (TAG)"
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Kaya, Eda, Timothy Durrett, Scott Bean, Valentina Trinetta y Umut Yucel. "Effect of High Oleic Acetyl Triacylglycerol (acetyl-TAG) on Functional Properties of Biodegradable Sorghum DDGS Packaging Film". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/vrtb4074.
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Justification: Biodegradable packaging films from biodiverse resources have gained popularity around the world in recent years due to environmental and sustainability concerns. A general challenge with biopolymer-based films is resistance against moisture and mechanical strength. We hypothesized that the functional properties of films from biopolymers can be improved by the presence of the sn-3 acetyl group of TAG, obtained from transgenic Camelina sativa. Objective:The aim of this study was to investigate the effect of acetyl-TAG as a plasticizer on the physiochemical properties of sorghum DDGS films.Methods:The acetyl-TAG with high oleic fatty acid composition (ca.70%) was extracted from transgenic camelina seeds using hexane. The composition of the purified oils was characterized by thin layer chromatography (TLC) and LC-MS. Sorghum DDGS were pretreated via wet (Colloid mill) and dry milling (Udy mill), and co-dissolved with gum plasticizers in a mixture of organic (i.e., ethanol, chloroform) and aqueous solvents. The acetyl-TAG was added to the mixture as a plasticizer (0, 0.1, 0.2% w/v). Films were characterized for their thermal properties (DSC), tensile strength, elongation (texture analyzer), thickness (micro caliper) and color (Hunter LAB colorimeter). ResultsAddition of acetyl-TAG significantly affected the mechanical properties of the films. Tensile strength significantly (p< 0.05) increased to 39.54 ± 0.04 MPa when acetyl-TAG (0.2% w/v) was added as compared to 20.77 ± 0.03 MPa of films without ace-TAG. The plasticizing resistance increased with the highest enthalpy of melting (2.51 J) for the films with 0.2% (w/v) ace-TAG. Physical properties, such as color, were significantly improved by addition of acetyl-TAG (i.e., the maximum lightness L* (66.7) obtained in with 0.2% ace-TAG).Significance:High oleic acetyl-TAG from engineered Camelina seeds can be used to improve the physicochemical properties of sorghum DDGS films as a novel and high-yield plasticizer.
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Park, Mi Soon, Yu Jin Lee y In-Hwan Kim. "Synthesis of Pinolenic Acid Enriched Triacylglycerol from Pine Nut Oil via a Two-step Consecutive Enzyme Reaction". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/jlcw3538.
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Pinolenic acid (PLA), Δ‐5,9,12‐octadecatrienoic acid-C18:3, is a plant origin polyunsaturated fatty acid and is contained abundantly in pine nut oil. PLA has several health benefits, such as the reduction of atherosclerosis, inflammation, and blood pressure. In addition, PLA may work as an appetite suppressant by increasing the effect of satiety hormones, such as cholecystokinin and glucagon-like peptide-1. The aim of this study was to synthesize PLA-enriched TAG from pine nut oil via a two-step lipase-catalyzed reaction, which is ethanolysis and esterification. In the first step, PLA was enriched up to ca. 42% as ethyl ester form, from 14% in pine nut oil by Lipozyme 435-catalyzed ethanolysis with an excess amount of ethanol. In the second step, PLA-enriched TAG was synthesized with glycerol and two different acyl donors, PLA-enriched fatty acid and PLA-enriched ethyl ester via Lipozyme 435-catalyzed esterification under vacuum condition. The TAG conversion and reaction rate with fatty acid form were significantly higher than those with ethyl ester form. Thus, the effect of temperature and vacuum on the synthesis of PLA-enriched TAG were investigated with fatty acid form as an acyl donor. The optimum temperature and vacuum were 60 oC and 5 torr, respectively. The TAG conversion of approximately 95% was achieved after 12 h under the optimum conditions. In addition, fatty acid compositions of TAG synthesized at different reaction times were also explored.
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Yoon, Hui su y In-Hwan Kim. "Lipozyme TL IM-catalyzed synthesis of γ-linolenic acid rich triacylglycerol from borage oil as a novel strategy". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/sgec7971.
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Lipozyme TL IM from Thermomyces lanuginosus is widely employed for various enzymatic reactions such as esterification, hydrolysis, and alcoholysis. However, none of the publications is using Lipozyme TL IM as a biocatalyst to synthesize triacylglycerol (TAG) with fatty acid and glycerol because the silica gel carrier in Lipozyme TL IM aggregates with glycerol. Thus, most studies regarding the synthesis of TAG via lipase-catalyzed esterification have employed Novozym 435, one of the most expensive enzymes. In present study, we attempted to synthesize TAG using Lipozyme TL IM with glyceride, instead of glycerol, and fatty acid as a novel strategy; as a result, γ-linolenic acid (GLA) rich TAG was synthesized successfully via esterification using Lipozyme TL IM. In the first step, GLA was enriched into glyceride fraction from borage oil by C. rugosa lipase-catalyzed hydrolysis and the GLA rich glyceride was separated from the reaction mixture using short-path distillation. GLA was enriched up to 45.9% in glyceride fraction from an initial value of 20.6% under the optimum conditions, which are the temperature of 40 °C and the enzyme loading of 0.05% (based on the oil weight of the total substrate). In the second step, GLA rich TAG was synthesized with the GLA rich glyceride, instead of glycerol, and the fatty acid obtained from part of the GLA rich glyceride by saponification using Lipozyme TL IM as a biocatalyst. The optimum conditions were the temperature of 50 °C, the enzyme loading of 10%, and the vacuum level of 5 torr, respectively. Consequently, the maximum TAG conversion of ca. 93% was achieved after 24 h under the optimum condition.
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Kaya, Eda, Dallas Johnson, Timothy Durrett y Umut Yucel. "Response Surface Methodology Optimization of the Use of Acetyl-triacylglycerol for Improving the Structure of Whey Protein Foams". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/xirn5178.
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Foam stability, capacity and viscoelastic properties are essential for foods such as whipped cream and meringue and can be controlled using novel surface-active ingredients. The 3-acetyl-1,2-diacyl-sn-glycerols (acetyl-TAG) obtained from transgenic Camelina sativa with controlled fatty acid composition and purity at high yield, can serve as a suitable compound to improve foam properties for food applications.Objective: The study is aimed to decrease sucrose content in a model whipped cream formulated by whey protein isolate (WPI) and incorporation of a novel ingredient: acetyl-TAG.Methods:The foam was prepared by mixing WPI, sucrose and acetyl-TAG in deionized water (200 mL) by Box-Wilson design: whey protein isolate (WPI) (2, 4, 6, 8, 10%(w/v)), sucrose (10, 15, 20, 25, 30%(w/w)) and acetyl-TAG (ATC) (0, 0.25, 0.5, 0.75, 1 (w/v)). Foam was whipped using Hamilton Beach 6 speed mixer (Southern Pines, NC, USA) at the highest speed for 20 min with 5 min intervals. SAS software package (Version 9.4 TS Level 1M5) was used for response surface methodology and linear regression model fitting for each response. Foam overrun (FO), serum drainage (FD), dynamic interfacial elasticity (E'), complex modulus (|E|) and viscosity (E’’) were analyzed.Results: Acetyl-TAG was composed of palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2), α-linolenic acid (18:3) and eicosapentaenoic acid (EPA) (20:1) as analyzed by thin layer chromatography (TLC) and LC-MS. Foam overrun (max 1100%) was significantly maximized (P< 0.01) by WPI (10% (w/v)) and ATC (0.5% (w/w)), but not sucrose concentration. Viscoelastic properties and stability were significantly (P< 0.01) affected by all process variables. The highest |E| and E' (80 and 75 mN/m, respectively) were recorded with higher acetyl-TAG (above 0.5% w/w).Significance:Novel ingredient, acetyl-TAG, obtained from transgenic camelina seeds can serve as a potential foam stabilizer in reduced-sugar foam formulations, such as whipped cream.
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Lee, Yu Jin, Changhwan Ju y In-Hwan Kim. "Novel Strategy for Synthesis of Stearidonic Acid Enriched Triacylglycerol from Ahiflower Seed Oil via a Two-step Enzyme Reaction". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/uhjd7801.
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Stearidonic acid (SDA) is a plant-based n-3 polyunsaturated fatty acids (PUFAs) with several positive therapeutic effects on human health such as reducing risks of cardiovascular diseases, obesity, inflammation, and cancer. Moreover, the conversion efficiency of SDA to EPA is significantly higher than α-linolenic acid to EPA, in the human body. Plant oils with SDA, such as ahiflower seed oil and echium seed oil, exhibit substantially higher oxidative stability than fish oil with EPA and DHA, the most popular n-3 PUFA. The present study has successfully carried out the enrichment of SDA and the synthesis of triacylglycerol (TAG) consecutively via two lipase-catalyzed reactions, which are selective hydrolysis and esterification, while most of n-3 PUFAs studies have separately employed its enrichment and the synthesis of TAG. SDA was enriched into a glyceride fraction from ahiflower seed oil by Candida rugosa lipase-catalyzed selective hydrolysis, and the SDA-enriched glycerides were separated from the reaction mixture using molecular distillation. SDA was enriched up to 40.7 mol% in glyceride fraction from an initial value of 21.6 mol% under the optimum conditions of 35 oC, and 0.1% enzyme loading relative to the weight of the total substrate. Then, SDA-enriched TAG was synthesized from the SDA-enriched glycerides and the fatty acid obtained from part of the SDA-enriched glycerides by saponification via esterification using an in-house immobilized lipase as a biocatalyst. The in-house immobilized lipase was prepared from Eversa® Transform 2.0 (liquid form) using Lewatit VP OC 1600 as a carrier. The maximum TAG yield of ca. 94% was achieved after 12 h under the optimum conditions, which are the temperature of 50 oC, the enzyme loading of 10 % relative to the weight of the total substrate, and the vacuum of 10 torr."
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Kim, In-Hwan, Dongchan Oh y Suhyeon Choi. "Production of value-added oleochemicals via Eversa immobilized lipase-catalyzed esterification". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/lqbh2911.
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Eversa lipase (from Themomyces lanuginosus) as a liquid type was developed to produce biodiesel. In our previous study, diisononyl adipate was effectively synthesized with an immobilized lipase prepared from Eversa lipase using Lewatit VP OC 1600 as a carrier. In this study, two oleochemicals, palmitoleic acid rich triacylglycerol (TAG) and 2-ethylhexyl palmitate, were successfully synthesized by Eversa immobilized lipase-catalyzed esterification. The palmitoleic acid rich TAG was synthesized from macadamia nut oil via two-step enzymatic reactions, which are C. rugosa lipase-catalyzed hydrolysis and Eversa immobilized lipase-catalyzed esterification. 2-Ethylhexyl palmitate, which is widely used as a cosmetic ingredient, was synthesized from 2-ethylhexanol and palmitic acid in a solvent-free system via Eversa immobilized lipase-catalyzed esterification. In both studies, Eversa immobilized lipase exhibited significantly higher activity for the synthesis of 2-ethylhexyl palmitate than Novozym 435, which is known as a commercial lipase with substantially high activity for esterification. In addition, Eversa immobilized lipase exhibited similar activity for the synthesis of palmitoleic acid rich TAG compared to the Novozym 435.
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Golodnizky, Daniel, Carlos E. S. Bernardes, Maya Davidovich-Pinhas, Ronit Bitton y Yulia Shmidov. "Isotropic liquid state of triacylglycerols: The starting point of fats and oils crystallization". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/ggfh1118.
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Over the years, several models of triacylglycerol (TAG) molecular conformations and bulk arrangements in isotropic liquid state have been proposed and are still up for debate. This organization is the starting state, from which the molecules self-assemble and form the initial stable nucleus, which then grows to form the solid crystal. The current research aims to explore the isotropic liquid state, while focusing on its impact on nucleation and crystal formation. This aim was addressed by implementing experimental methods, such as X-ray diffraction and small-angle X-ray scattering coupled with a computational method, such as molecular dynamics simulation. These techniques were used to study tristearin and triolein as models for saturated and unsaturated TAGs, respectively. Four different conformations were suggested for the two TAGs, and the results showed conformation abundancy in the order: trident (Tr) > chair (Ch) > propeller (Pr) > tuning-fork (Tf). The existence of clusters was demonstrated, each of which exhibited a heterogeneous distribution of conformations. The preferability to find a specific pair of conformations next to each other was analyzed and, surprisingly, it was found that Tf will preferably pair only with Tr although Tf is the preferable conformation in most crystal polymorphs. High general conversion rates from any conformation to another, and high specific conversion rates from and to the Tf conformation were calculated. It is proposed that the high conversion rates observed enable the crystallization process, despite the low proportion of Tf molecules. Overall, the results confirm the formation of specific structures in the liquid state, which combine all previously suggested models and further expand the knowledge using experimental and computational tools.
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Miyashita, Kazuo y Masashi Hosokawa. "Inhibitory effect of sphingoid bases on the oxidative flavor deterioration of fish oil." En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/wzfw6692.
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Sphingoid bases (SPG), a backbone of sphingolipids, are kind of amino alcohol containing long carbon chains. Although the importance of SPG as major component of sphingolipids is well-known, little attention has been paid to the nutritional and chemical properties of SPG itself. Recently, we have found that SPG supplementation to diet-induced obese animals significantly attenuated the abdominal adipose tissue weight gain and the hyperglycemia. Furthermore, we have reported the strong ability of SPG to inhibit the oxidative deterioration of EPA- and DHA-containing oils such as fish oil. Fish oil triacylglycerol (TAG) just after being refined by chromatographic separation has little to no flavor. However, the TAG shows an unpleasant smell less than 1 hr after leaving the chromatograph at room temperature. Although antioxidants and other methods such as microencapsulation in a matrix are used to control the fish oil oxidation, it is still difficult to completely prevent the formation of unpleasant fishy and rancid odors. On the contrary, we have found the effective prevention of the volatile formation in the fish oil TAG oxidation by SPG. The antioxidant activity of SPG synergistically increased in the presence of general antioxidants such as tocopherols. The most likely mechanism for the antioxidant activity of SPG is the formation of novel antioxidants by the amino-carbonyl reaction between the amine group of SPG and the carbonyl group of aldehydes, which are formed in a very early stage of the fish oil oxidation. At the same time, the reaction can result in the removal of aldehydes responsible for flavor deterioration.
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Li, Ye Ling y Amanda Wright. "Static in vitro Digestibility Impacted by Emulsion Crystallinity Under Different Experimental Conditions". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/iwtm4185.
Texto completoResumen
Understanding better how triacylglycerol (TAG) crystallinity alters lipid digestion should help to clarify the contributions of dietary lipids to postprandial lipemia. The static in vitro digestibility of o/w Span 60 emulsions with similarly sized (~ 500 nm in diameter) palm olein (PO) control or palm stearin (PS) droplets tempered to contain maximal (PS-SE) and partial (PS-SE-25 °C) crystallinity or to remain undercooled (PS-LE) at 37 °C was compared. With low shear and no preceding gastric phase, duodenal lipolysis quantified using a commercial enzymatic assay did not differ up to 10 minutes (p> 0.05) while particle size also did not differ (p> 0.05). Lipolysis then trended higher for the liquid emulsions (i.e., PO and PS-LE), but ultimately did not differ between samples. With low shear gastro-duodenal digestion, PO hydrolysis was unexpectedly lower compared to PS-SE and PS-LE throughout the duodenal phase potentially due to higher particle diameter and stabilizing effects of TAG crystallinity on colloidal properties. Higher shear in the gastro-duodenal digestion attenuated early lipolysis for all PS emulsions but not PO which was digested faster up to 60 minutes and differed from the other samples (p< 0.05). The results were related to differences in particle size such that the extra shear redispersed the acidic-flocculated PO droplets and this may have occurred to a lesser extent in the presence of crystalline TAG. The PS-LE sample, although liquid initially, experienced low level crystallization during digestion which led it to differ from the liquid control PO. Therefore, particle size measured during in vitro digestion indicated that TAG crystallinity differences affected colloidal behaviour and had an overall attenuating effect on lipid digestibility under the most physiologically relevant conditions. The work has relevance to postprandial lipemia since lipid digestibility may modulate lipemic response.
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Bukowski, Michael, Brij Singh, James Roemmich y Kate Larson. "Lipidomic analysis of TRPC1 Ca2+-permeable channel-knock out mouse demonstrates a vital role in placental tissue sphingolipid and triacylglycerol homeostasis under high-fat diet". En 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/tjdt4839.
Texto completoResumen
Placental function including oxygen delivery and nutrient transport are critical determinants of fetal growth, moderating the risks of obesity and metabolic diseases later in life. Previously, we demonstrated in a mouse model that parental diet and exercise play important roles in placental lipid content and inflammation. Transient receptor potential canonical channel 1 (TRPC1) is a Ca2+-permeable integral membrane protein. We have demonstrated that TRPC1 increases total body adiposity in mice by decreasing the efficacy of exercise to limit adipose accumulation under a high fat (HF) diet. Importantly, intracellular calcium may regulate total body adiposity and increased total body adiposity could promote placental lipid accumulation. Similarly, intracellular calcium regulates membrane lipid content via the activation of the protein kinase C. Membrane lipids such as sphingomyelin are key regulators of cell signaling. Maternal HF diets increase placental tissue lipid concentrations resulting in compromised nutrient transport to fetus. However, the specific lipid species that accumulate due to the absence of the placental TRPC1 gene under maternal HF diet feeding is not yet known. We hypothesized that placental tissue response to a maternal HF diet is disrupted in TRPC1 mice fed a maternal HF diet resulting in greater cellular sphingomyelin concentrations. Results showed placentae from TRPC1 KO mice fed high fat diet (45% en, HF) had increased sphingomyelin concentrations compared to control diet (16% en, NF). Placentae from WT mice fed HF diet exhibited diet-dependent increases in ceramide concentration with no concomitant increase in sphingomyelins compared to NF fed WT mice. Additionally, 11 placental triacylglycerol (TAG) species were different based on diet, 16 based on genotype, and 5 were affected by both diet and genotype. These results suggest that during a HF diet, loss of TRPC1 function reduces placental sphingomyelin hydrolysis into ceramide and that placental TAG concentrations respond in diet- and genotype-dependent manner.
Informes sobre el tema "Triacylglycerol (TAG)"
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Sukenik, Assaf, Paul Roessler y John Ohlrogge. Biochemical and Physiological Regulation of Lipid Synthesis in Unicellular Algae with Special Emphasis on W-3 Very Long Chain Lipids. United States Department of Agriculture, enero de 1995. http://dx.doi.org/10.32747/1995.7604932.bard.
Texto completoResumen
Various unicellular algae produce omega-3 (w3) very-long-chain polyunsaturated fatty acids (VLC-PUFA), which are rarely found in higher plants. In this research and other studies from our laboratories, it has been demonstrated that the marine unicellular alga Nannochloropsis (Eustigmatophyceae) can be used as a reliable and high quality source for the w3 VLC-PUFA eicosapentaenoic acid (EPA). This alga is widely used in mariculture systems as the primary component of the artificial food chain in fish larvae production, mainly due to its high EPA content. Furthermore, w3 fatty acids are essential for humans as dietary supplements and may have therapeutic benefits. The goal of this research proposal was to understand the physiological and biochemical mechanisms which regulate the synthesis and accumulation of glycerolipids enriched with w3 VLC-PUFA in Nannochloropsis. The results of our studies demonstrate various aspects of lipid synthesis and its regulation in the alga: 1. Variations in lipid class composition imposed by various environmental conditions were determined with special emphasis on the relative abundance of the molecular species of triacylglycerol (TAG) and monogalactosyl diacylglycerol (MGDG). 2. The relationships between the cellular content of major glycerolipids (TAG and MGDG) and the enzymes involved in their synthesis were studied. The results suggested the importance of UDP-galactose diacylglycerol galactosyl (UDGT) in regulation of the cellular level of MGDG. In a current effort we have purified UDGT several hundredfold from Nannochloropsis. It is our aim to purify this enzyme to near homogeneity and to produce antibodies against this enzyme in order to provide the tools for elucidation of the biochemical mechanisms that regulate this enzyme and carbon allocation into galactolipids. 3. Our in vitro and in vivo labeling studies indicated the possibility that phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are associated with desaturation of the structural lipids, whereas shorter chain saturated fatty acids are more likely to be incorporated into TAG. 4. Isolation of several putative mutants of Nannochloropsis which appear to have different lipid and fatty acid compositions than the wild type; a mutant of a special importance that is devoid of EPA was fully characterized. In addition, we could demonstrate the feasibility of Nannochloropsis biomass production for aquaculture and human health: 1) We demonstrated in semi-industrial scale the feasibility of mass production of Nannochloropsis biomass in collaboration with the algae plant NBT in Eilat; 2) Nutritional studies verified the importance algal w3 fatty acids for the development of rats and demonstrated that Nannochloropsis biomass fed to pregnant and lactating rats can benefit their offspring.