Letteratura scientifica selezionata sul tema "Acid-Selection"
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Articoli di riviste sul tema "Acid-Selection":
1
Massingham, Tim, e Nick Goldman. "Detecting Amino Acid Sites Under Positive Selection and Purifying Selection". Genetics 169, n. 3 (16 gennaio 2005): 1753–62. http://dx.doi.org/10.1534/genetics.104.032144.
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Silva, Jack da. "ANTIBODY SELECTION AND AMINO ACID REVERSIONS". Evolution 66, n. 10 (21 maggio 2012): 3079–87. http://dx.doi.org/10.1111/j.1558-5646.2012.01686.x.
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Howieson, J. G., M. A. Ewing e M. F. D'Antuono. "Selection for acid tolerance inRhizobium meliloti". Plant and Soil 105, n. 2 (settembre 1988): 179–88. http://dx.doi.org/10.1007/bf02376781.
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Krištofíková, L., M. Rosenberg, A. Vlnová, J. Šajbidor e M. Čertík. "Selection ofRhizopus strains forl(+)-lactic acid andγ-linolenic acid production". Folia Microbiologica 36, n. 5 (ottobre 1991): 451–55. http://dx.doi.org/10.1007/bf02884065.
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Váchová, A., Z. Panovská e D. Lukešová. "The Selection of the Optimal Rate of Acid and Sweet Taste for Lemon Flavoured Drops". Czech Journal of Food Sciences 27, Special Issue 1 (24 giugno 2009): S330—S332. http://dx.doi.org/10.17221/942-cjfs.
Abstract (sommario):
The objective of this work was to choose an optimal rate of citric acid and sweeteners for lemon flavoured drops. Two model samples with defined concentrations of citric acid and two commercial samples were evaluated with using instrumental and sensory methods. Concentrations of sweetening agents and citric acid in the samples were determined using HPLC with a RI detector and isotachophoresis, respectively. The general pleasantness of taste and the intensity of acid and sweet tastes of four lemon drops were evaluated using sensory analysis. General pleasantness was evaluated using a ranking test. Intensities of acid and sweet tastes were evaluated using unstructured graphic scales. The best tasting lemon drops contained 11 g/kg of citric acid and 691 g/kg sweeteners related to the sweet potency of sucrose. The sample with an extremely acid taste was considered unpleasant for most assessors (Friedman, α= 0.05). Generally, the assessors preferred the lemon drops with well-balanced acid and sweet tastes.
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Asehraou, A., N. Ghabbour, Z. Lamzira, P. Thonart, P. Cidalia e M. Markaoui. "Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives". Grasas y Aceites 62, n. 1 (17 febbraio 2011): 84–89. http://dx.doi.org/10.3989/gya.055510.
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Ha, Thi Quyen, e Thi Minh Tu Hoa. "Selection of lactic acid bacteria producing bacteriocin". Journal of Vietnamese Environment 8, n. 5 (17 gennaio 2017): 271–76. http://dx.doi.org/10.13141/jve.vol8.no5.pp271-276.
Abstract (sommario):
Lactic acid bacteria were isolated from 10 samples of the traditionally fermented foods (5 samples of Vietnamese fermented pork roll and 5 samples of the salted field cabbage) and 5 samples of fresh cow milks collected from households in Vietnam. 22 strains of lactic acid bacteria were isolated for inhibition to Lactobacillus plantarum JCM 1149. Of these, only 2 strains including DC1.8 and NC1.2 have rod shape, the others have coccus shape. 7 strains showing higher antibacterial activity were selected for checking spectrum of antibacteria with indicator bacteria consistting of Bacillus subtilis ATCC 6633, Enterococcus faecium JCM 5804 and Staphylococcus aureus TLU. By which, 3 strains including NC3.5 (from Vietnamese fermented pork roll), DC1.8 (from salted field cabbage) and MC3.19 (from fresh cow milk) were selected because of their higher antibacterial ability. However, the antibacterial activity of the lactic acid bacteria can be based on their disposable compounds and some other antibacterial compounds produced during their growth (such as lactic acid, H2O2, bacteriocins, etc.). For seeking lactic acid bacteria with capability of producing bacteriocins, antibacterial compounds with protein nature, 3 above strains were checked sensitiveness to proteases (including protease K, papain, α – chymotrypsin and trypsin). Because bacteriocins are proteinaceous antibacterial compounds, so their antibacterial activity will be reduced if proteases are added. The result showed DC1.8 and MC3.19 were capable of producing bacteriocin during culture process. They were identified as Lactobacillus acidophilus and Lactococcus lactis and classified, respectively, based on analysis chemical characterisitcs by standard API 50 CHL kit and phylogeny relationship by 16s rRNA sequences.
Các chủng vi khuẩn lactic được phân lập từ 10 mẫu thực phẩm lên men truyền thống (5 mẫu nem chua, 5 mẫu dưa cải bẹ muối) và 5 mẫu sữa bò tươi được thu thập từ các hộ gia đình ở Việt Nam. 22 chủng vi khuẩn lactic đã được phân lập với tiêu chí có khả năng kháng lại vi khuẩn kiểm định Lactobacillus plantarum JCM 1149. Trong số đó, 2 chủng DC1.8 và NC1.2 có tế bào hình que, các chủng còn lại có tế bào hình cầu. 7 chủng thể hiện hoạt tính kháng khuẩn cao được lựa chọn để xác định phổ kháng khuẩn rộng hơn với ba loài vi khuẩn kiểm định Bacillus subtilis ATCC 6633, Enterococcus faecium JCM 5804 và Staphylococcus aureus TLU. Từ đó lựa chọn được 3 chủng có hoạt tính kháng khuẩn cao hơn hẳn. Các chủng này gồm NC3.5 phân lập từ nem chua, DC1.8 phân lập từ dưa cải bẹ muối và MC3.19 phân lập từ sữa bò tươi. Tuy nhiên, hoạt tính kháng khuẩn của vi khuẩn lactic bao gồm những hợp chất nội tại có trong nó và cả những hợp chất được sinh ra trong quá trình phát triển của nó (như axit lactic, H2O2, bacteriocin, …). Với định hướng tìm chủng vi khuẩn lactic có khả năng sinh bacteriocin, chất kháng khuẩn có bản chất protein, 3 chủng trên được kiểm tra độ nhạy cảm với các protease (gồm protease K, papain, α – chymotrypsin và trypsin). Do bacteriocin là chất kháng khuẩn có bản chất protein nên hoạt tính kháng khuẩn của chúng sẽ bị giảm nếu protease được bổ xung vào. Kết quả lựa chọn được chủng DC1.8 và MC3.19 có khả năng sinh bacteriocin. Hai chủng này được phân loại đến loài nhờ vào phân tích đặc điểm sinh hóa bằng kit API 50 CHL và mối quan hệ di truyền thông qua trình tự gen 16s rRNA. Kết quả phân loại đã xác định chủng DC1.8 thuộc loài Lactobacillus acidophilus và chủng MC3.19 thuộc loài Lactococcus lactis.
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Mart�nez-Force, Enrique, e Tah�a Ben�tez. "Selection of amino-acid overproducer yeast mutants". Current Genetics 21, n. 3 (marzo 1992): 191–96. http://dx.doi.org/10.1007/bf00336840.
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Parmegiani, Lodovico, Graciela Estela Cognigni, Walter Ciampaglia, Patrizia Pocognoli, Francesca Marchi e Marco Filicori. "Efficiency of hyaluronic acid (HA) sperm selection". Journal of Assisted Reproduction and Genetics 27, n. 1 (30 dicembre 2009): 13–16. http://dx.doi.org/10.1007/s10815-009-9380-0.
10
Foxe, J. P., V. u. N. Dar, H. Zheng, M. Nordborg, B. S. Gaut e S. I. Wright. "Selection on Amino Acid Substitutions in Arabidopsis". Molecular Biology and Evolution 25, n. 7 (3 aprile 2008): 1375–83. http://dx.doi.org/10.1093/molbev/msn079.
Tesi sul tema "Acid-Selection":
1
Ha, Thi Quyen, e Thi Minh Tu Hoa. "Selection of lactic acid bacteria producing bacteriocin". Technische Universität Dresden, 2016. https://tud.qucosa.de/id/qucosa%3A32636.
Abstract (sommario):
Lactic acid bacteria were isolated from 10 samples of the traditionally fermented foods (5 samples of Vietnamese fermented pork roll and 5 samples of the salted field cabbage) and 5 samples of fresh cow milks collected from households in Vietnam. 22 strains of lactic acid bacteria were isolated for inhibition to Lactobacillus plantarum JCM 1149. Of these, only 2 strains including DC1.8 and NC1.2 have rod shape, the others have coccus shape. 7 strains showing higher antibacterial activity
were selected for checking spectrum of antibacteria with indicator bacteria consistting of Bacillus subtilis ATCC 6633, Enterococcus faecium JCM 5804 and Staphylococcus aureus TLU. By which, 3 strains including NC3.5 (from Vietnamese fermented pork roll), DC1.8 (from salted field cabbage) and MC3.19 (from fresh cow milk) were selected because of their higher antibacterial ability. However, the antibacterial activity of the lactic acid bacteria can be based on their disposable compounds and some other antibacterial compounds produced during their growth (such as lactic acid, H2O2, bacteriocins, etc.). For seeking lactic acid bacteria with capability of producing bacteriocins, antibacterial compounds with protein nature, 3 above strains were checked sensitiveness to proteases (including protease K, papain, α – chymotrypsin and trypsin). Because bacteriocins are proteinaceous antibacterial compounds, so their antibacterial activity will be reduced if proteases are added. The result showed DC1.8 and MC3.19 were capable of producing bacteriocin during culture process. They were identified as Lactobacillus acidophilus and Lactococcus lactis and classified, respectively, based on analysis chemical characterisitcs by standard API 50 CHL kit and phylogeny relationship by 16s rRNA sequences.Các chủng vi khuẩn lactic được phân lập từ 10 mẫu thực phẩm lên men truyền thống (5 mẫu nem chua, 5 mẫu dưa cải bẹ muối) và 5 mẫu sữa bò tươi được thu thập từ các hộ gia đình ở Việt Nam. 22 chủng vi khuẩn lactic đã được phân lập với tiêu chí có khả năng kháng lại vi khuẩn kiểm định Lactobacillus plantarum JCM 1149. Trong số đó, 2 chủng DC1.8 và NC1.2 có tế bào hình que, các chủng còn lại có tế bào hình cầu. 7 chủng thể hiện hoạt tính kháng khuẩn cao được lựa chọn để xác định phổ kháng khuẩn rộng hơn với ba loài vi khuẩn kiểm định Bacillus subtilis ATCC 6633, Enterococcus faecium JCM 5804 và Staphylococcus aureus TLU. Từ đó lựa chọn được 3 chủng có hoạt tính kháng khuẩn cao hơn hẳn. Các chủng này gồm NC3.5 phân lập từ nem chua, DC1.8 phân lập từ dưa cải bẹ muối và MC3.19 phân lập từ sữa bò tươi. Tuy nhiên, hoạt tính kháng khuẩn của vi khuẩn lactic bao gồm những hợp chất nội tại có trong nó và cả những hợp chất được sinh ra trong quá trình phát triển của nó (như axit lactic, H2O2, bacteriocin, …). Với định hướng tìm chủng vi khuẩn lactic có khả năng sinh bacteriocin, chất kháng khuẩn có bản chất protein, 3 chủng trên được kiểm tra độ nhạy cảm với các protease (gồm protease K, papain, α – chymotrypsin và trypsin). Do bacteriocin là chất kháng khuẩn có bản chất protein nên hoạt tính kháng khuẩn của chúng sẽ bị giảm nếu protease được bổ xung vào. Kết quả lựa chọn được chủng DC1.8 và MC3.19 có khả năng sinh bacteriocin. Hai chủng này được phân loại đến loài nhờ vào phân tích đặc điểm sinh hóa bằng kit API 50 CHL và mối quan hệ di truyền thông qua trình tự gen 16s rRNA. Kết quả phân loại đã xác định chủng DC1.8 thuộc loài Lactobacillus acidophilus và chủng MC3.19 thuộc loài Lactococcus lactis.
2
Sainz, Perez Florencia. "Selection and optimization of acetic acid bacteria for d-gluconic acid production". Doctoral thesis, Universitat Rovira i Virgili, 2016. http://hdl.handle.net/10803/401541.
Abstract (sommario):
En aquesta tesi doctoral, es va realitzar la selecció de bacteris acètics (BA) per a dur a terme una fermentació selectiva de D-glucosa en àcid D-glucònic, sense consum de fructosa. Es seleccionaren tres soques de BA, dues pertanyents al gènere Gluconobacter i una altre del gènere Acetobacter, sent les soques de Gluconobacter les millors preparades per a aquesta oxidació. Es va mesurar l'activitat de les deshidrogenases de membrana que participen en l'oxidació completa de la D-glucosa. A més, es van seqüenciar els gens que codifiquen per aquests enzims i es van utilitzar per construir arbres filogenètics, obtenint com a resultat que els gèneres Acetobacter i Gluconobacter queden separats en diferents grups. També es van estudiar els requeriments nutricionals de les BA, centrant-se principalment en la utilització de nitrogen. El creixement d'aquests bacteris va ser millor en els medis amb una combinació completa d'aminoàcids i d'amoni. Les soques seleccionades es van seqüenciar per millorar els protocols de seguiment d'aquests bacteris durant el procésEn esta tesis doctoral, se realizó la selección de bacterias acéticas (BA) para llevar a cabo una fermentación selectiva de D-glucosa en ácido D-glucónico, sin consumo de fructosa. Se seleccionaron tres cepas de BA, dos de ellas pertenecientes al género Gluconobacter y otra del género Acetobacter, siendo las cepas de Gluconobacter las mejor preparadas para esta oxidación. Se midió la actividad de las deshidrogenasas de membrana que participan en la oxidación completa de la D-glucosa. Además, se secuenciaron los genes que codifican para estas enzimas y se utilizaron para construir árboles filogenéticos, obteniendo como resultado que los géneros Acetobacter y Gluconobacter quedan separados en diferentes grupos. También se estudiaron los requerimientos nutricionales de las BA, centrándose principalmente en la utilización de nitrógeno. El crecimiento de estas bacterias fue mejor en los medios con una combinación completa de aminoácidos y de amonio. Las cepas seleccionadas se secuenciaron para mejorar los protocolos de seguimiento de estas bacterias durante el proceso
In this PhD thesis, the selection of Acetic acid bacteria (AAB) was carried out to perform a selective fermentation of D-glucose into D-gluconic acid, without consuming fructose. Three AAB strains were selected, two of them belonging to the Gluconobacter genus and another to Acetobacter, being the Gluconobacter strains better prepared for this oxidation. The activities of the membrane-bound dehydrogenases involved in the complete oxidation of D-glucose were measured. Furthermore, the genes encoding for these enzymes were sequenced and used to construct phylogenetic trees, obtaining as a result that Acetobacter and Gluconobacter genera grouped into different clusters. The nutritional requirements, mainly focused on nitrogen, for AAB were also studied. The growth of these bacteria was better in media with a complete combination of amino acids and ammonium. The selected strains were sequenced to improve the monitoring protocols for these bacteria in the process.
3
Šinkūnienė, Dovilė. "Lipase selection and application for fatty acid ester synthesis". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140210_082745-97488.
Abstract (sommario):
Lipases are widely researched enzyme group because of their ability to catalyze a wide range of synthesis reactions. The aim of this doctoral thesis was to study and optimize fatty acid ester synthesis using lipases. The influence of enzyme choice, its preparation (immobilization), choice of substrates and reaction conditions on fat hydrolysis, biodiesel and phenethyloctanoate (flavour ester) synthesis reaction course and yield was studied. Enterobacter aerogenes lipase, which was developed in Lithuania, was immobilized and its properties were determined for the first time. Commercial lipases were used for hydrolysis and synthesis reactions, the influence of reaction parameters was determined using response surface methodology, and so the yield was optimized. Silica gel was found to be a promising reaction additive for acyl group migration catalysis in biodiesel synthesis reaction. Different lipase specificities towards different acylglycerol classes and regioisomers varied greatly; on the basis of this knowledge two-step biodiesel synthesis catalysis was proposed.Lipazių atranka ir taikymas riebalų rūgščių esterių sintezei Lipazės yra intensyviai tiriama fermentų grupė dėl jų gebos katalizuoti platų spektrą sintezės reakcijų. Disertacinio darbo tikslas buvo ištirti ir optimizuoti riebalų rūgščių esterių sintezės, panaudojant lipazes, būdus. Tirta fermento preparato paruošimo (imobilizavimo), fermento bei substratų pasirinkimo bei reakcijos sąlygų ir priedų įtaka riebalų hidrolizės, biodyzelino, fenetiloktanoato (kvapiojo esterio) sintezės reakcijų eigai ir išeigai. Pirmą kartą ištirtos Lietuvoje paruoštos Enterobacter aerogenes lipazės savybės, ji imobilizuota ant gamtinės kilmės nešiklių. Komercinių lipazių katalizuojamų reakcijų sąlygų įtakai nustatyti ir reakcijos išeigai optimizuoti naudota atsako paviršiaus metodologija. Tiriant reakcijos priedų įtaką acilgrupės migracijai ir biodyzelino sintezės reakcijai, nustatyta, kad perspektyvus priedas yra silikagelis. Lipazių specifiškumas ženkliai skiriasi skirtingoms acilglicerolių klasėms ir regioizomerams, šių žinių pagrindu buvo pasiūlyta dviejų etapų biodyzelino sintezės katalizė.
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Teramoto, Naozumi. "Synthesis of Novel Functional Nucleic Acid Derivatives by In Vitro Selection". Kyoto University, 2000. http://hdl.handle.net/2433/180977.
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Piao, Xijun. "Bifacial PNA in Nucleic Acid Folding, Peptide Ligation and in vitro Selection". The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1468585976.
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McGilchrist, Peter. "Selection for muscling affects carbohydrate and fatty acid metabolism in beef cattle". Thesis, McGilchrist, Peter (2011) Selection for muscling affects carbohydrate and fatty acid metabolism in beef cattle. PhD thesis, Murdoch University, 2011. https://researchrepository.murdoch.edu.au/id/eprint/14808/.
Abstract (sommario):
Genetic selection to enhance muscularity in beef cattle is desirable to increase retail beef yield and the profitability of the beef industry. However it is unknown how selection for greater muscling will impact on intermediary and muscle energy metabolism which may influence certain attributes of meat quality. In order to assess these impacts of selection for greater muscling in cattle, the physiological mechanisms that underpin the increase in retail beef yield must be identified. This thesis examined the impact of selection for greater muscling on: retail beef yield; muscle glycogen; whole body insulin responsiveness; adrenaline responsiveness of muscle, adipose and liver tissue; and proportion of glycolytic and oxidative myofibres and enzyme activities. This study used 11 high (High), 10 low (Low) and 3 high muscled steers with a myostatin mutation (HighHet) from an Angus herd which had been visually selected for divergence in muscling over 15 years.
The results of the yield test performed at bone-out showed that the HighHet and High muscled steers were the highest yielding with the lowest proportion of fat, while the Low muscling animals were the lowest yielding with the highest proportion of fat. Muscle glycogen and lactate concentration were analysed from four muscle biopsies, taken between 18 and 24 months of age, from the m. semimembranosus (SM), m. semitendinosus (ST) and m. longissimus thoracis et lumborum (LTL) of each animal. The muscle glycogen concentrations which were 6.1% higher in the High steers compared to the Low animals while the HighHet did not differ from either group.
The effect of selection for muscling on whole body insulin responsiveness was measured using the hyperinsulineamic-euglyceamic clamp technique. Insulin was constantly infused at 2 levels, glucose was concurrently infused to maintain euglyceamia, and the steady-state glucose infusion rate (SSGIR) indicated insulin responsiveness. At the low insulin infusion rate of 0.6 mU/kg/min, the SSGIR was 73% higher for the High muscling genotype animals when compared to the Low. At the high insulin infusion rate of 6.0 mU/kg/min, these differences were proportionately less with the High and the HighHet genotypes having only 27% and 34% higher SSGIR than the Low muscled genotype. The High muscled cattle also had 30% higher plasma IGF-1 concentrations compared to the Low muscled cattle. The increased whole body insulin responsiveness in combination with higher IGF-1 concentrations in the High muscled steers is likely to initiate a greater level of protein synthesis, which may partially explain the increased muscle accretion in these animals. Increased insulin responsiveness in the High steers would also increase glycogenesis in the muscle, aligning with the glycogen results.
The effect of selection for muscling on adrenaline responsiveness was measured using 7 adrenaline challenges ranging between 0.2 to 3.0 μg/kg liveweight. Plasma was analysed for NEFA, lactate, glucose and growth hormone concentration and area under curve (AUC) over time was calculated to reflect the tissue responses to adrenaline. The High steers had 30% lower lactate AUC than the Low steers at challenges greater than 2 μg/kg live weight, indicating lower muscle responsiveness at the highest adrenaline doses causing less glycogenolysis. This result also aligns with these animals having more muscle glycogen, thus more muscular animals may reduce the incidence of dark, firm, dry meat that is caused by low levels of glycogen at slaughter. At all levels of adrenaline challenge the High steers had at least 30% greater NEFA AUC, indicating that their adipose tissue was more responsive to adrenaline, resulting in greater lipolysis. In agreement with this response, the High steers had a higher plasma growth hormone concentration, which is likely to have contributed to the increased lipolysis evident in these animals in response to adrenaline. This difference in lipolysis may in part explain the reduced fatness of muscular cattle. There was no effect of selection for muscling on liver responsiveness to adrenaline.
Contrary to our initial hypotheses, the High steers had less glycolytic type IIX myofibres in the LTL and larger average cross-sectional area of myofibres in the SM and ST than their Low muscled counterparts. This suggests that myofibre hypertrophy may be a possible mechanism leading to greater muscle mass of these High muscled animals. This also indicates that breeding for more muscular cattle can actually maintain the oxidative capacity of the muscle, a finding supported by the enzymatic results showing that the High muscled steers had lower activity of lactate dehydrogenase and higher activity of citrate synthase and isocitrate dehydrogenase. The High muscled cattle also had a higher concentration of iron in the LTL, and selection for increased muscling had no impact on pH decline or retail colour stability, factors which both affect meat quality.
The aim of the second experiment was to determine if phenotypic measurements taken at the time of grading for Meat Standards Australia (MSA) could explain variance in ultimate pH (pHu) of carcasses and the probability of a carcass complying with MSA standards for pHu (≤5.7). Analyses of 204,072 carcass records collated by MSA at a Western Australian processor confirmed that more muscular cattle have a higher compliance rate for pHu. An increase in eye muscle area from 40 to 80 cm2, increased pHu compliance by approximately 14%. Therefore animals with greater muscularity had a lower incidence of dark, firm, dry beef supporting the results that High muscled cattle have increased insulin responsiveness, and reduced adrenaline responsiveness, leading to increased glycogen storage at slaughter. Thus, breeding more muscular cattle with eye muscle area greater than 70 cm2 may help alleviate the problem of dark, firm, dry beef. As rib fat depth increased from 0 to 20mm, pHu compliance increased by around 10%. Heavier cattle also had higher compliance than lighter cattle, and younger cattle also had higher compliance rates. This highlights the importance of good nutrition and high muscle glycogen storage prior to slaughter to maximise compliance rates.
The final study examined 81 commercially managed High and Low muscled steers and showed that the effects of muscularity on muscle glycogen were variable as pasture quality and availability changed however there were no negative effects of selection for greater muscling on muscle glycogen, glycogenolysis pre-slaughter, or on the incidence of dark, firm and dry carcasses. Animal temperament assessed using crush score and flight speed measurements did however affect muscle glycogen with the more flighty animals having lower muscle glycogen concentrations.
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Ros, Freixedes Roger. "Genetic analysis and selection for intramuscular fat and oleic acid content in pigs". Doctoral thesis, Universitat de Lleida, 2014. http://hdl.handle.net/10803/285933.
Abstract (sommario):
El contingut i la composició en àcids grassos del greix intramuscular (GIM) afecten la qualitat de la carn de porc. En particular, augmentar el contingut d’àcid oleic (C18:1) milloraria la seva qualitat pel que fa a atributs organolèptics i tecnològics i propietats nutricionals. Aquesta tesi doctoral forma part d’una línia de recerca del Grup de Millora Genètica del Porcí de la Universitat de Lleida, amb l’objectiu final de trobar estratègies per millorar genèticament la qualitat de la carn de porc a través de GIM i C18:1. Es divideix en tres parts. La Part 1 discuteix les implicacions d’aplicar un enfocament estadístic específic per a dades composicionals per analitzar aquests caràcters. Es va mostrar que, com que la variabilitat de la composició del greix de la carn de porc és baixa, les tècniques estadístiques estàndards sobre percentatges bruts són suficientment robustes per la majoria d’anàlisis, incloent les que es realitzen a continuació. En la Part 2, en una línia Duroc, es va estimar que GIM i C18:1 tenen una heretabilitat alta similar (0.51−0.56, per a GIM, i 0.44−0.50, per a C18:1) i una correlació favorable entre ells (0.47). A més, existeixen escenaris de selecció en què aquests caràcters i el creixement magre es poden millorar simultàniament. Es va demostrar experimentalment que (1) GIM i C18:1 responen a la selecció basada en valors de millora a partir de dades fenotípiques de parents, i (2) l’espessor de greix dorsal es pot modificar independentment de GIM i C18:1. No obstant, la selecció per GIM i C18:1 basada en dades preses en un múscul té respostes correlacionades desiguals en altres músculs i teixits adiposos. En la Part 3 es van analitzar les variacions de la seqüència del gen estearoil-CoA desaturasa (SCD), que codifica l’enzim limitant en la biosíntesi de C18:1. Es va mostrar que hi ha una variant funcional en el gen SCD amb un efecte additiu de +0.75% en C18:1 i +1.00% en contingut total d’àcids grassos monoinsaturats, però sense efecte en GIM o engreixament de la canal. Aquesta associació es va confirmar en un estudi d’associació genòmica que també va revelar variacions de nucleòtids en el locus del gen del receptor de la leptina (LEPR) que afecten el nivell d’engreixament i, en conseqüència, la composició del greix. L’ús de marcadors en aquests dos loci va millorar substancialment la precisió en les prediccions de GIM i C18:1. Es conclou que és possible seleccionar amb èxit per GIM i C18:1 en carn de porc i es discuteixen diversos escenaris sobre com implementar aquesta selecció a la pràctica.El contenido y la composición en ácidos grasos de la grasa intramuscular (GIM) afectan la calidad de la carne de cerdo. En particular, aumentar el contenido de ácido oleico (C18:1) mejoraría su calidad en cuanto a atributos organolépticos y tecnológicos y propiedades nutricionales. Esta tesis doctoral forma parte de una línea de investigación del Grupo de Mejora Genética del Porcino de la Universitat de Lleida, con el objetivo final de encontrar estrategias para mejorar genéticamente la calidad de la carne de cerdo a través de GIM y C18:1. Se divide en tres partes. La Parte 1 discute las implicaciones de aplicar un enfoque estadístico específico para datos composicionales para analizar estos caracteres. Se mostró que, como la variabilidad de la composición de la grasa de la carne de cerdo es baja, las técnicas estadísticas estándares sobre porcentajes brutos son suficientemente robustas para la mayoría de análisis, incluyendo los que se realizan a continuación. En la Parte 2, en una línea Duroc, se estimó que GIM y C18:1 tienen una heredabilidad alta similar (0.51−0.56, para GIM, y 0.44−0.50, para C18:1) y una correlación favorable entre ellos (0.47). Además, existen escenarios de selección en que estos caracteres y el crecimiento magro se pueden mejorar simultáneamente. Se demostró experimentalmente que (1) GIM y C18:1 responden a la selección basada en valores de mejora a partir de datos fenotípicos de parientes, y (2) el espesor de grasa dorsal se puede modificar independientemente de GIM y C18:1. No obstante, la selección por GIM y C18:1 basada en datos tomados en un músculo tiene respuestas correlacionadas desiguales en otros músculos y tejidos adiposos. En la Parte 3 se analizaron las variaciones de la secuencia del gen estearoil-CoA desaturasa (SCD), que codifica el enzima limitante en la biosíntesis de C18:1. Se mostró que hay una variante funcional en el gen SCD con un efecto aditivo de +0.75% en C18:1 y +1.00% en contenido total de ácidos grasos monoinsaturados, pero sin efecto en GIM o engrasamiento de la canal. Esta asociación se confirmó en un estudio de asociación genómica que también reveló variaciones de nucleótidos en el locus del gen del receptor de la leptina (LEPR) que afectan el nivel de engrasamiento y, en consecuencia, la composición de la grasa. El uso marcadores en estos dos loci mejoró substancialmente la precisión en las predicciones de GIM y C18:1. Se concluye que es posible seleccionar con éxito por GIM y C18:1 en carne de cerdo y se discuten varios escenarios sobre como implementar esta selección en la práctica.
Intramuscular fat (IMF) content and fatty acid composition affect the quality of pork. In particular, increasing oleic acid (C18:1) content would improve pork quality in terms of organoleptic and technological attributes and also of nutritional properties. This thesis dissertation is part of a line of research conducted by the Pig Breeding and Genetics Group of the University of Lleida, with the aim of finding strategies to genetically improve pork quality by increasing IMF and C18:1. It is divided into three parts. Part 1 discusses the implications of applying a specific statistical approach for compositional data to analyze these traits. It is shown that, because of the low variability of fatty acid composition in pork, the standard statistical techniques on raw percentages are robust enough for most genetic analyses, including those performed next. In Part 2, the genetic parameters associated to IMF and C18:1 were estimated in a purebred Duroc line. Both traits have a similar high heritability (0.51−0.56, for IMF, and 0.44−0.50, for C18:1) and a favorable genetic correlation between them (0.47). Furthermore, there exist selection scenarios where these traits and lean growth can be improved simultaneously. It was proved experimentally that (1) IMF and C18:1 respond effectively to selection on estimated breeding values based on phenotypic data of relatives, and (2) backfat thickness can be modified independently of IMF and C18:1. However, selection for IMF and C18:1 based on records from one muscle has unequal correlated responses on other muscles and fat tissues. In Part 3, the sequence variation of the stearoyl- CoA desaturase (SCD) gene, the gene producing the rate-limiting enzyme in the biosynthesis of C18:1, was analyzed. It was shown that there is a functional variant in the promoter of the SCD gene with an average additive effect of +0.75% and +1.00% on C18:1 and total monounsaturated fatty acids, respectively, but no effect on IMF or carcass fatness. This was confirmed in a genome-wide association study which also revealed nucleotide variations in the leptin receptor (LEPR) gene locus affecting overall fatness and, as a result, fat composition. The use markers at both loci substantially enhanced the accuracy of prediction of IMF and C18:1. It is concluded that it is possible to successfully select for increased IMF and C18:1 in pork. In light of the results obtained several scenarios are discussed on how to implement such selection in practice.
8
Bale, S. J. "The selection of haloaliphatic acid dehalogenases in continuous-flow cultures of Pseudomonas putida". Thesis, Cardiff University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384225.
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Benjamin, Yuda L. "Sugarcane cultivar selection for ethanol production using dilute acid pretreatment, enzymatic hydrolysis and fermentation". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86525.
Abstract (sommario):
Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: The development of ―energycane‖ varieties of sugarcane for ethanol production is underway, targeting the use of both sugar juice (first generation ethanol) and bagasse (second generation ethanol). Nevertheless, identification of the preferred varieties represents the biggest challenge to the development of energycane due to large number of samples produced during breeding. In the present study, dilute acid pretreatment, enzymatic hydrolysis and fermentation processes were used to evaluate the processability of bagasse (fibrous residue generated after juice sugar extraction) from different varieties of sugarcane to select preferred varieties with the properties of improving combined ethanol yield (ethanol from juice and bagasse) per hectare. The impact of variety selection on combined ethanol yield (ethanol from juice and bagasse) per hectare was also assessed. In the first part of this study, 115 varieties of sugarcane originated from classical breeding and precision breeding (genetic engineering) were screened based on agronomic data and experimental data from biochemical processes (dilute acid pretreatment and enzymatic hydrolysis) applied to the bagasse fraction of each variety. The results showed wide variations in the chemical composition of bagasse between the varieties. Structural carbohydrates and lignin content ranged from 66.6 to 77.6% dry matter (DM) and 14.4 to 23.1% DM, respectively. The majority of precision breeding varieties showed higher arabinoxylan, lower lignin and lower ash content than most of classical breeding varieties. Combined sugar yield from the bagasse after pretreatment and enzymatic hydrolysis also varied significantly among the varieties. Up to 27.9 g/100g (dry bagasse) difference in combined sugar yield was observed. Combined sugar yield was inversely correlated with lignin as well as ash content, but it correlated positively with structural carbohydrates content. Total potential ethanol yields per hectare, calculated based on cane yield, soluble and non-soluble sugar content also differed significantly among the varieties (8,602−18,244 L/ha). Potential ethanol from bagasse contributed approximately one third of the total potential ethanol yield. Interestingly, some of the varieties had combined properties of high potential ethanol yield per hectare and improved bagasse convertibility. Thus, six varieties (3 from each breeding technology) were selected as preferred varieties for further investigation. To enhance sugar yield from bagasse, optimisation of pretreatment was conducted on the selected varieties. Industrial bagasse was included for comparison purposes. The pretreatment optimisation was based on maximising combined sugar yield from the combined pretreatment-hydrolysis process. A central composite design (CCD) was applied to investigate the effects of temperature, acid concentration and residence time on the responses and was later used to determine the maximum combined sugar yield. Pretreatment optimisation was conducted at gram scale (22.9 ml reactor) and at bench scale (1000 ml reactor). Significant differences in sugar yields (xylose, glucose, and combined sugar) between the varieties were observed. The combined sugar yields from the best performing varieties and industrial bagasse at optimal pretreatment-hydrolysis conditions differed by up to 34.1% and 33% at gram and bench scale, respectively. A high ratio of carbohydrates to lignin and low ash contents increased the release of sugar from the substrates. At mild pretreatment conditions, the differences in bioconversion efficiency between varieties were greater than at severe conditions. This observation suggests that under less severe conditions the conversion efficiency was largely determined by the properties of the biomass. Furthermore, it was demonstrated that the pretreatment conditions with temperature ranged from 184 to 200 °C and varying residence time to provide a severity factor between 3.51 and 3.96 was observed to be the area in common where 95% of maximum combined sugar yield could be obtained. Simultaneous Saccharification and Fermentation (SSF) was performed on the unwashed pressed-slurry from bagasse pretreatment at conditions for maximum combined sugar yield at bench scale. Batch and fed-batch SSF feeding strategy at different solid loadings and enzyme dosages were used aiming to reach an ethanol concentration of at least 40 g/L. The results revealed significant improvement in overall ethanol yield after SSF for the selected varieties (84.5–85.6%) compared to industrial bagasse (74.8%). The maximum ethanol concentration from the best performing varieties was 48.6−51.3 g/l and for poor performing varieties was 37.1−38.3 g/l. Ethanol concentration in the fermentation broth was inversely correlated with lignin content and the ratio of xylose to arabinose, but it showed positive correlation with glucose yield from pretreatment-enzymatic hydrolysis. The overall assessment of the varieties showed greater improvement in combined ethanol yields per hectare (71.1–90.7%) for the best performing varieties with respect to industrial sugarcane. The performance in terms of ethanol yields of selected varieties from a number harvest years was evaluated. The results showed considerable variations in ethanol yields across harvests. The results showed that the best variety in terms combined ethanol yield was not maintained across harvests. The differences in ethanol yields were greater among the varieties than across the harvests. Prolonged severe drought significantly affected the ethnol yields of all varieties represented by lower and intermediate lignin content for cane yield compared to that which had highest lignin content. However, carbohydrates content in the bagasse and sugar yield/recovery between the harvest years did not change for the most of the varieties. In summary, the present study provides evidence of the impact of cultivar selection and pretreatment optimisation in increasing conversion efficiency of bagasse. The results demonstrate that varieties with lower lignin and ash content, as well as highly substituted xylan resulted in higher sugar and ethanol yields. These results suggest that lower process requirements can be achieved without adversely affecting juice ethanol and cane yield per hectare. Nonetheless, an attempt to reduce lignin content in the bagasse, to reduce processing requirements for ethanol production, can also target the improvement of crop tolerance toward severe drought conditions.
AFRIKAANSE OPSOMMING: Die ontwikkeling van ―energie-riet‖ rasse vir etanol produksie is goed op dreef, waar beide die sap (eerste generasie etanol) en die bagasse (tweede generasie etanol) geteiken word. Die groot aantal monsters wat tydens teling geproduseer word, bied egter die grootste uitdaging vir die identifisering van nuwe rasse ten einde energie-riet te ontwikkel. In die huidige studie is verdunde suurvoorbehandeling, ensiematiese hidrolise en fermentasie-prosesse gebruik om die verwerkbaarheid van bagasse (veselagtige residu gegenereer na sap suiker ekstraksie) van verskillende suikerrietrasse te evalueer om nuwe variëteite te selekteer wat eienskappe van verbeterde gekombineerde etanolopbrengs (etanol van sap en bagasse) per hektaar toon. Die impak van variëteit-seleksie op gekombineerde etanol opbrengs (etanol van sap en bagasse) per hektaar is ook beoordeel. In die eerste deel van hierdie studie het uit ‗n siftingsproses van 115 suikerriet rasse bestaan wat deur klassieke en presisie (geneties gemodifiseerde) teling gegenereer is. Die sifting was op agronomiese data gebaseer, asook op data van verdunde suur voorafbehandeling en ensimatiese hidrolise eksperimente wat op die bagasse fraksie van elke ras uitgevoer is. Die resultate het op groot variasie in die chemiese samestelling van die bagasse van verskillende rasse gedui. Die strukturele koolhidrate het tussen 66.6 en 77.6% droë massa (DM) gewissel, terwyl die lignien inhoud ‗n variasie van 14.4 en 23.1% DM getoon het. Verder het meeste van die presisie-teling variëteite ‗n hoër arabinoxilaan, maar ‗n laer lignien en as-inhoud as meeste van die klassieke teling rasse gehad. Die gekombineerde suikeropbrengs (GSO) van die bagasse na voorafbehandeling en ensimatiese hidrolise het ook beduidend tussen rasse gewissel, waar ‗n verskil van tot 27.9 g/100g (droë bagasse) waargeneem is. Daar was ‗n omgekeerde korrelasie tussen die gekombineerde suikeropbrengs en die lignien en as-inhoud gewees, maar die opbrengs het ‗n sterk positiewe korrelasie met die strukturele koolhidrate getoon. Die totale potensiële etanol opbrengs per hektaar wat vanaf die suikerriet se oplosbare en nie-oplosbare suikerinhoud bereken is, het ook beduidend tussen rasse verskil (8,602−18,244 L/ha), waar die potensiële etanol opbrengs van die bagasse gedeelte ongeveer een derde van die totale potensiële etanol opbrengs beslaan het. Interessante bevindinge het op sommige rasse met gekombineerde eienskappe van hoë potensiële opbrengs per hektaar asook ‗n hoë omskakelingsvermoë gedui. Derhalwe is ses variëteite (drie van elke telingstegnologie) as voorkeurvariëteite vir verdere studie gekies. Om die etanol opbrengs vanaf die bagasse te verbeter was voorafbehandeling van die voorkeurvariëteite geoptimeer, en waar industriële bagasse vir vergelykingsdoeleindes ingesluit was. Vir die optimering was dit ten doel gestel om die gekombineerde suikeropbrengs van die gekombineerde voorafbehandeling-hidrolise proses te maksimeer. ‗n Sentrale saamgestelde ontwerp (SSO) is gebruik om die effek van temperatuur, suurkonsentrasie en residensietyd op die responsveranderlikes vas te stel wat uiteindelik gebruik is om die maksimum gekombineerde suikeropbrengs te bepaal. Die optimering van die voorafbehandeling is op gram-skaal in ‗n 22.9 ml reaktor, asook op bank-skaal in ‗n 1000 ml reaktor uitgevoer. Beduidende verskille in die suikeropbrengs (xilose, glukose en gekombineerde suiker) is tussen die voorkeurrasse waargeneem. Tussen die rasse wat die beste gevaar het, asook die industriële bagasse, het die gekombineerde suikeropbrengs by optimale voorafbehandeling-hidrolise toestande onderskeidelik met tot 34.1% en 33% op gram-skaal en bank-skaal gevarieer. ‗n Hoë verhouding van koolhidrate tot lignien, asook ‗n lae as-inhoud het tot ‗n toename in die vrystelling van suiker uit die substraat gelei. By matige voorafbehandelingstoestande was die verskille in omskakelingseffektiwiteit tussen rasse groter as onder hewige toestande, wat daarop gedui het dat omskakelingseffektiwiteit grotendeels deur die eienskappe van die biomassa bepaal is. Verder is daar ook gedemonstreer dat die voorbehandelingsomstandighede met temperatuur tussen 184 en 200ºC en verandering van die residensietyd om 'n hewigheidsfaktor van tussen 3.51 en 3.96 te verskaf, 'n gemeenskaplike area gelewer het waar 95% van maksimum gekombineer suiker opbrengs (GSO) verkry kon word. Gelyktydige versuikering en fermentasie (GVF) is na voorafbehandeling op ongewaste, gepersde bagasse substraat by toestande vir die maksimum gekombineerde suikeropbrengs op bank-skaal uitgevoer. Bondel en voerbondel SSF voerstrategie by verskillende vaste ladings en ensiemdoserings is gebruik om 'n etanol konsentrasie van ten minste 40 g/L te bereik. Ná GVF was die algehele etanol opbrengs vir die voorkeurvariëteite (84.5–85.6%) beduidend beter relatief tot die industriële bagasse (74.8%). Die maksimum etanol opbrengs na SSF van die rasse met die beste prestasie was 48.6-51.3 g/L en 37.1-38.3 g/L vir rasse wat swak presteer het. Die etanol konsentrasie in die fermentasiesop was omgekeerd met lignien en die verhouding van xilose tot arabinose gekorreleer, maar was duidelik positief met die glukose opbrengs vanaf voorafbehandeling-hidrolise gekorreleer. ‗n Algemene assessering het op ‗n duidelike verbetering van die voorkeurvariëteite in terme van gekombineerde etanol opbrengs per hektaar gedui (71.1–90.7%), relatief tot die industriële suikerriet. Die prestasie in terme van etanol opbrengs van geselekteerde variëteite is oor 'n reeks oesjare ge-evalueer. Die resultate het aansienlike variasies in etanol opbrengs oor oesjare getoon. Die resultate het gewys dat die beste variëteite in terme van gekombineerde etanol opbrengs nie volhou is oor oeste nie. Die verskille in etanol opbrengste tussen variëteite was groter as die verskille oor oesjare. Verlengde ernstige droogte het die etanol opbrengs van alle variëteite met laer en intermediere lignien inhoud vir rietopbrengs aansienlik beinvloed, in vergelyking met dié wat die hoogste lignien inhoud gehad het. Die koolhidraatinhoud in die bagasse en suiker opbrengs/lewering tussen die oesjare het vir die meeste variëteite egter nie gewissel nie. Ter opsomming, die huidige studie verskaf bewyse van die impak van kultivarseleksie en voorbehandelings optimisering op die verhoging van die omskakelings-doeltreffendheid van bagasse. Die resultate wys dat variëteite met laer lignien- en asinhoud, en hoogs-gesubstitueerde xilaan hoër suiker- en etanol opbrengs gelewer het. Hierdie resultate stel voor dat verminderde voorbehandelingsvereistes bereik kan word sonder om die sap etanol en rietopbrengs per hektar te benadeel. Nieteenstaande, 'n poging om die lignien inhoud van die bagasse te verminder om die verwerkingsvereistes vir etanolproduksie te verminder, kan ook die verbetering van gewas-toleransie tov ernstige droogte-toestande teiken.
10
Burkett, Jeremy Lenn. "The effect of selection for intramuscular fat on fatty acid composition in Duroc pigs". [Ames, Iowa : Iowa State University], 2009.
Libri sul tema "Acid-Selection":
1
Schillmoller, C. M. Selection and use of stainless steels and nickel-bearing alloys in nitric acid. Toronto, Ont: Nickel Development Institute, 1992.
2
IEEE Standards Coordinating Committee 29 on Stationary Batteries., Institute of Electrical and Electronics Engineers. e IEEE Standards Board, a cura di. IEEE guide for selection of valve-regulated lead-acid (VRLA) batteries for stationary applications. New York, N.Y., USA: Institute of Electrical and Electronics Engineers, 1996.
3
Michael, Davies. Alloy selection for service in sulphuric acid: A guide to the use of nickel-containing alloys. Toronto, Ont: Nickel Institute, 2019.
4
Coudriet, L. Selection of turbojett mixer provides innovation and flexibility for a new acid mine drainage (AMD) treatment plant. S.l: s.n, 1987.
5
Hydro, Ontario. Report to the Lieutenant Governor in Council: Options available to meet acid gas limits and selection of preferred options. Toronto, Ont: Ontario Hydro, 1989.
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Dillon, C. P., e Davies Michael. Alloy selection for service in hydrogen fluoride, hydrofluoric acid and fluorine: A guide to the use of nickel-containing alloys. Toronto: Nickel Institute, 2019.
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Davies, Michael. Alloy selection for service in chlorine, hydrogen chloride and hydrochloric acid: A guide to the use of nickel-containing alloys. Toronto, Ont: Nickel Institute, 2018.
8
Nexant, Inc. Survey and down-selection of acid gas removal systems for the thermochemical conversion of biomass to ethanol with a detailed analysis of an MDEA system. Golden, CO: National Renewable Energy Laboratory, 2011.
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Simpson, J. C. Uncertainty in North American wet deposition isopleth maps: Effect of site selection and valid sample criteria. Research Triangle Park, NC: U.S. Environmental Protection Agency, Atmospheric Research and Exposure Assessment Laboratory, 1990.
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Simpson, J. C. Uncertainty in North American wet deposition isopleth maps: Effect of site selection and valid sample criteria. Research Triangle Park, NC: U.S. Environmental Protection Agency, Atmospheric Research and Exposure Assessment Laboratory, 1990.
Capitoli di libri sul tema "Acid-Selection":
1
Breaker, R. R., e M. Kurz. "In Vitro Selection of Nucleic Acid Enzymes". In Current Topics in Microbiology and Immunology, 137–58. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-60142-2_8.
2
Nasr-Esfahani, Mohammad Hossein, e Tavalaee Marziyeh. "Sperm Selection for ICSI Using the Hyaluronic Acid Binding Assay". In Methods in Molecular Biology, 263–68. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-038-0_24.
3
Horváth, Ilona Sárvári, Anders Sjöde, Nils-Olof Nilvebrant, Andrei Zagorodni e Leif J. Jönsson. "Selection of Anion Exchangers for Detoxification of Dilute-Acid Hydrolysates from Spruce". In Proceedings of the Twenty-Fifth Symposium on Biotechnology for Fuels and Chemicals Held May 4–7, 2003, in Breckenridge, CO, 525–38. Totowa, NJ: Humana Press, 2004. http://dx.doi.org/10.1007/978-1-59259-837-3_44.
4
Huszar, Gabor. "Sperm Testing and ICSI Selection by Hyaluronic Acid Binding: The Hyaluronic Acid-Coated Glass Slide and Petri Dish in the Andrology and IVF Laboratories". In Gamete Assessment, Selection and Micromanipulation in ART, 93–120. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-8360-1_7.
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Caradus, J. R. "Selection for improved adaptation of white clover to low phosphorus and acid soils". In Developments in Plant Breeding, 167–78. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0966-6_20.
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Tanous, Catherine, Agnieszka Kieronczyk, Sandra Helinck, Emilie Chambellon e Mireille Yvon. "Glutamate dehydrogenase activity: a major criterion for the selection of flavour-producing lactic acid bacteria strains". In Lactic Acid Bacteria: Genetics, Metabolism and Applications, 271–78. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-017-2029-8_17.
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Kuo, T. M., e T. Kaneshiro. "Selection of Saprophytic Bacteria and Characterization of Their Fatty Acid Bioconversions during Compost Formation". In ACS Symposium Series, 55–64. Washington, DC: American Chemical Society, 2001. http://dx.doi.org/10.1021/bk-2001-0776.ch004.
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Samizadeh, Souphiyeh, e Kyungkook Hong. "Poly-l-lactic Acid Cone Threads–Silhouette Soft Threads—Patient Selection and Treatment Procedure". In Thread Lifting Techniques for Facial Rejuvenation and Recontouring, 315–30. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-47954-0_17.
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Smith, John A., Zhuoru Liu, Kevin P. Williams, Daniel B. Kassel, Birgit Roellinger e Yie-Hwa Chang. "Single amino acid substitution alters T-cell determinant selection during antigen processing of staphylococcal nuclease". In Peptides 1990, 895–97. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3034-9_367.
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Russo, Pasquale, Nicola De Simone, Vittorio Capozzi, Mari Luz Mohedano, José Ángel Ruiz-Masó, Gloria del Solar, Paloma López e Giuseppe Spano. "Selection of Riboflavin Overproducing Strains of Lactic Acid Bacteria and Riboflavin Direct Quantification by Fluorescence". In Methods in Molecular Biology, 3–14. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1286-6_1.
Atti di convegni sul tema "Acid-Selection":
1
Mathis, Stephen P., e Sharon B. Malochee. "Improved Diverter Selection for Acid-Prepack Gravel Pack Completions". In SPE European Formation Damage Conference. Society of Petroleum Engineers, 1997. http://dx.doi.org/10.2118/38188-ms.
2
Baxa, Michael S., Richard A. Hamann e Richard J. Scarvaci. "Selection of Design Parameters for Sealed Lead-Acid Batteries". In INTELEC '86. IEEE, 1986. http://dx.doi.org/10.1109/intlec.1986.4794405.
3
Dusseault, M. B., B. C. Davidson e T. Spanos. "New Screening Criteria For Selection Of Acid-Foam Surfactants". In Technical Meeting / Petroleum Conference of The South Saskatchewan Section. Petroleum Society of Canada, 1999. http://dx.doi.org/10.2118/99-92.
4
"Pertinent Parameters Selection for Processing of Short Amino Acid Sequences". In International Workshop on Pattern Recognition in Information Systems. SciTePress - Science and and Technology Publications, 2010. http://dx.doi.org/10.5220/0003040600250032.
5
Westhof, Eric. "Isostericity, tautomerism and geometric selection of nucleic acid base pairs". In XVIth Symposium on Chemistry of Nucleic Acid Components. Prague: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 2014. http://dx.doi.org/10.1135/css201414056.
6
Hall-Thompson, Bryan, Arias Rommel Ernesto, Nutaifi Abdulrahman e Abdulaziz Alsuhaimi. "Acid Stimulation-Best Practices for Design, Selection and Testing of Acid Recipes in Low Permeability Carbonate Reservoirs". In International Petroleum Technology Conference. International Petroleum Technology Conference, 2020. http://dx.doi.org/10.2523/iptc-19690-ms.
7
Węcławski, Jakub, Stanisław Jankowski e Zbigniew Szymański. "Feature selection from short amino acid sequences in phosphorylation prediction problem". In Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments 2012, a cura di Ryszard S. Romaniuk. SPIE, 2012. http://dx.doi.org/10.1117/12.2001270.
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Khaeva, Oksana, Boris Tsugkiev e Larisa Ikoeva. "Isolation and Selection of Propionic Acid Bacteria Promising for Biotechnological Production". In Proceedings of the 1st International Symposium Innovations in Life Sciences (ISILS 2019). Paris, France: Atlantis Press, 2019. http://dx.doi.org/10.2991/isils-19.2019.33.
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Huifeng, Liu, Xu Ning, Liu Qi, Tian Hongzhao, Ming Yue e Chen Zhangxin. "Selection of Acid Types to Achieve Uniform Stimulation in Long Laterals of Horizontal Wells". In ADIPEC. SPE, 2023. http://dx.doi.org/10.2118/216067-ms.
Abstract (sommario):
Abstract Horizontal wells with long laterals are being used to develop low-permeability carbonate reservoirs in the world. After completion of a well, acidizing is usually conducted to remove the potential damage caused by drilling and completion. However, in bullheading acid injection, it is usually difficult for the acid to distribute evenly along a lateral due to quick consumption of acid along the wellbore, especially in MRC (Maximum Reservoir Contact) wells or wells with long laterals (>1000m). In many cases the toe area is even left un-stimulated at all. Different types of retarded acids are being developed in industry to reduce acid consumption rate in order to let them penetrate further, but the effective travelling distances of these acids are never systemically studied and compared, leaving field engineers a difficulty in selecting an acid for a specific well. In our work, the properties of different types of acids in industry are reviewed. A flow and reaction model with consideration of acid flow friction and acid-rock reaction kinetics is established and a method is found to solve it. Five typical cases are run based on the model and the results of an effective acid flowing distance, effective acid reacting distance and effective acid travelling distance are obtained and compared. Based on our study, two principles of selecting acid types for horizontal wells with long laterals are proposed: "flow to the toe" and "react to the toe", which mean the friction of an acid as well as the leak off rate of the acid should be small enough to let the fluid reach the toe under a given injection rate; the diffusion rate of H+ and the acid-rock reaction rate must be small enough to ensure that the acid is still active when it reaches the toe. Four key considerations are proposed regarding acid type selection: acid flow friction, acid leak off rate, mass transfer of H+, and acid-rock reaction rate. A general guideline for the key parameter control and acid type selection to achieve a good acid distribution in the wellbore under different conditions is also shown. Field engineers can use our guideline to select acid candidates initially, and then use our model and program to quantitatively evaluate if the acid can effectively cover the whole lateral length.
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Hartman, R. L., B. Lecerf, W. Frenier, M. Ziauddin e H. S. Fogler. "Acid Sensitive Aluminosilicates: Dissolution Kinetics and Fluid Selection for Matrix Stimulation Treatments". In SPE European Formation Damage Conference. Society of Petroleum Engineers, 2003. http://dx.doi.org/10.2118/82267-ms.
Rapporti di organizzazioni sul tema "Acid-Selection":
1
Murphy, Mr Thomas F. PR-226-9315-R01 Effects of Phosphoric Acid Treatment on Fusion-Bonded Epoxy Coating Performance. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), ottobre 1994. http://dx.doi.org/10.55274/r0011905.
Abstract (sommario):
The objective of the research was to establish whether phosphoric acid treatment of line pipe should routinely be undertaken before the application of FBE coatings where chloride contamination is not present; to determine the levels of treatment which enhance or cause deterioration on the steel surface; to establish any synergism that may exist between specific FOE coatings and phosphoric acid treatment; to determine if coating performance correlates to residual phosphate on the steel surface, and to provide end-user companies with data to enable the proper selection of surface treatments for use with their selected FOE coating.
2
Burkett, Jeremy, Thomas J. Baas, Donald C. Beitz, Clint R. Schwab, Nick Berry e Shu Zhang. Correlated Response in Fatty Acid Composition after Five Generations of Selection for Intramuscular Fat in Duroc Pigs. Ames (Iowa): Iowa State University, gennaio 2008. http://dx.doi.org/10.31274/ans_air-180814-597.
3
Zlotkin, Eliahu, Shizuo G. Kamita, Nor Chejanovsky e S. Maeda. Targeting of an Expressed Insect Selective Neurotoxin by its Recombinant Baculovirus: Pharmacokinetic and Pharmacodynamic Aspects. United States Department of Agriculture, luglio 1995. http://dx.doi.org/10.32747/1995.7571354.bard.
Abstract (sommario):
Objectives: 1) Clarification of the mode of potentiation of an expressed insect selective neurotoxin (AaIT) by its recombinant baculovirus. 2) In vitro formation and/or modification of neuroactive polypeptides for the design of new improved recombinant baculoviruses. Results: 1) A combined utilization of bioassays, LM-cytochemistry, the highly resolutive EM immunogold and electrical recording from the CNS of baculovirus and AaIT - expressing – recombinant baculovirus infected larvae it has been shown that the recombinant virus potentiates the effect of the toxin. Potentiation is achieved through its continuous expression in the infected tracheal epithelia thus providing a: a) Local supply of freshly produced toxin in the vicinity of its traget sites; b) Translocation of the expressed toxin to the insect CNS. The latter exposes the recombinant toxin to new, critical, target sites which are inaccessible through the natural route of scorpion envenomation. 2) Subjecting a recombinant AaIT toxin to a newly designed system of random mutagenesis results in large numbers of new AaIT genes with amino acid substitutions. The new or modified toxin genes were inserted into a linear BmNPV expressed in silkworm cell culture and assayed on blowfly and silkworm larvae. Thus a system for mass formation and screening of neuroactive agents was developed. Contribution to agriculture: 1) Demonstration of the insecticidal mechanism, capacity and utility of the combination of neuroactive polypeptides and recombinant pathogens. 2) Development of a simple in vitro system for the formation and selection of new neuroactive polypeptides.
4
Harpaz, Sheenan, Steven G. Hughes e Pinhas Lindner. Optimization of Diet for Post Larvel/Juvenile Sea Bass and Hybrid Stripped Bass Based on Enzymatic Profiles of their Digestive Tracts. United States Department of Agriculture, dicembre 1995. http://dx.doi.org/10.32747/1995.7604924.bard.
Abstract (sommario):
The overall goal of this research work was to identify the main proteolytic activities which take place in the digestive tracts of young bass fish, and use the knowledge acquired in order to improve feed protein utilization in juvenile fish based on their digestive capacity. The results of the work clearly showed that the young fish possess the entire profile of proteolytic enzymes which is found in adult fish. Yet, in the young fish the level of activity is substantially lower per gram tissue (or gram protein) as compared with the activity found in the digestive tracts of the same fish at an older (larger) age. In addition it was found that the main proteolytic enzyme in these fish is chymotrypsin which accounts for almost 80% of the proteolytic activity. An effort aimed at enhancing this activity has lead to the interesting finding that alcohol substantially enhances the proteolytic activity of fish intestines. Fish intestinal homogenates were used in order to evaluate the suitability of various feeds for the fish. Potential feed proteins were subjected to the proteolytic activity of the fish enzymes in vitro, in a manner simulating the natural process. The proteolytic activity was monitored by the valuation of the products, i.e. amino acid released. This method has proven to be a powerful tool which enables us to predict with a very high degree of accuracy the potential of a feed to promote growth. Selection of feed based on the proteolytic capacity of the fish degestive tracts can now be implemented in feed formulation, as anticipated in the original research proposal.
5
Ginzberg, Idit, Richard E. Veilleux e James G. Tokuhisa. Identification and Allelic Variation of Genes Involved in the Potato Glycoalkaloid Biosynthetic Pathway. United States Department of Agriculture, agosto 2012. http://dx.doi.org/10.32747/2012.7593386.bard.
Abstract (sommario):
Steroidal glycoalkaloids (SGAs) are secondary metabolites being part of the plant defense response. The two major SGAs in cultivated potato (Solanum tuberosum) are α-chaconine and α-solanine, which exhibit strong cellular lytic properties and inhibit acetylcholinesterase activity, and are poisonous at high concentrations for humans. As SGAs are not destroyed during cooking and frying commercial cultivars have been bred to contain low levels, and their content in tubers should not exceed 20 mg/100 g fresh weight. However, environmental factors can increase tuber SGA content above the safe level. The focus of the proposed research was to apply genomic approaches to identify candidate genes that control potato SGA content in order to develop tools for potato improvement by marker-assisted selection and/or transgenic approaches. To this end, the objectives of the proposal included identification of genes, metabolic intermediates and allelic variations in the potato SGAbiosynthetic pathway. The SGAs are biosynthesized by the sterol branch of the mevalonic acid/isoprenoid pathway. Transgenic potato plants that overexpress 3-hydroxy-3-methylglutaryl-CoA reductase 1 (HMG1) or squalene synthase 1 (SQS1), key enzymes of the mevalonic acid/isoprenoid pathway, exhibited elevated levels of solanine and chaconine as well as induced expression of genes downstream the pathway. These results suggest of coordinated regulation of isoprenoid (primary) metabolism and SGA secondary metabolism. The transgenic plants were further used to identify new SGA-related candidate genes by cDNA-AFLP approach and a novel glycosyltransferase was isolated. In addition, genes involved in phytosterol biosynthesis may have dual role and synthesize defense-related steroidal metabolites, such as SGAs, via lanosterol pathway. Potato lanosterol synthase sequence (LAS) was isolated and used to prepare transgenic plants with overexpressing and silencing constructs. Plants are currently being analyzed for SGA content. The dynamics of SGA accumulation in the various organs of a potato species with high SGA content gave insights into the general regulation of SGA abundance. Leaf SGA levels in S. chacoense were 10 to 20-fold greater than those of S. tuberosum. The leptines, SGAs with strong antifeedant properties against Colorado potato beetles, were present in all aerial tissues except for early and mid-developmental stages of above ground stolons, and accounted for the high SGA content of S. chacoense. These results indicate the presence of regulatory mechanisms in most tissues except in stolons that limit the levels of α-solanine and α-chaconine and confine leptine accumulation to the aerial tissues. The genomes of cultivated and wild potato contain a 4-member gene family coding for SQS. Three orthologs were cloned as cDNAs from S. chacoense and heterologously expressed in E. coli. Squalene accumulated in all E. coli lines transformed with each of the three gene constructs. Differential transcript abundance in various organs and amino acid sequence differences in the conserved domains of three isoenzymes indicate subfunctionalization of SQS activity and triterpene/sterol metabolism. Because S. chacoense and S. phureja differ so greatly for presence and accumulation of SGAs, we selected four candidate genes from different points along the biosynthetic pathway to determine if chcor phuspecific alleles were associated with SGA expression in a segregating interspecific diploid population. For two of the four genes (HMG2 and SGT2) F2 plants with chcalleles expressed significantly greater total SGAs compared with heterozygotes and those with phualleles. Although there are other determinants of SGA biosynthesis and composition in potato, the ability of allelic states at two genes to affect SGA levels confirms some of the above transgenic work where chcalleles at two other loci altered SGA expression in Desiree. Present results reveal new opportunities to manipulate triterpene/sterol biosynthesis in more targeted ways with the objective of altering SGA content for both human health concerns and natural pesticide content without disrupting the essential metabolism and function of the phytosterol component of the membranes and the growth regulating brassinosteroids.
6
Sengupta-Gopalan, Champa, Shmuel Galili e Rachel Amir. Improving Methionine Content in Transgenic Forage Legumes. United States Department of Agriculture, febbraio 2001. http://dx.doi.org/10.32747/2001.7580671.bard.
Abstract (sommario):
Leguminous forage crops are high in proteins but deficient in S- amino acids. It has been shown that both wool quality and milk production can be limited by the post-ruminal supply of sulfur-containing amino acids. Efforts to use conventional plant breeding and cell selection techniques to increase the S-amino acid content of alfalfa have met with little success. With the objective to increase the S-amino acid content of forage legumes, the goal of this project was to co- express the methionine rich zein genes from corn along with a gene for a key enzyme in methionine biosynthesis, aspartate kinase(AK). The zeins are seed storage proteins from corn and are groupec into four distinct classes based on their amino acid sequence homologies. The b-zein (15kd) and the 6zein (10kD and 18kD) have proportionately high levels of methionine (10%, 22% and 28%, respectively). Initial studies from our lab had shown that while the 15kD zein accumulated to high levels in vegetative tissues of transgenic tobacco the l0kD zein did not. However, co-expression of the 10kD zein with the 15kD zein genes in tobacco showed stabilization of the 10kD zein and the co-localization of the 10kD and 15kD zein proteins in unique ER derived protein bodies. AK is the key enzyme for producing carbon skeletons for all amino acids of the aspartate family including methionine. It is, however, regulated by end-product feedback inhibition. The specific objectives of this proposal were: i. to co-express the 15kD zein with the 10/18kD zein genes in alfalfa in order to enhance the level of accumulation of the 10/18kD zein; ii. to increase methionine pools by expressing a feedback insensitive AK gene in transformants co-expressing the 15kD and 10/18kD zein genes. The Israeli partners were successful in expressing the AK gene in alfalfa which resulted in an increase in free and bound threonine but not in methionine (Galili et al., 2000). Since our target was to increase methionine pools, we changed our second objective to replace the AK gene with the gene for cystathionine gamma synthase (CGS) in the co-expression studies. The first methionine specific reaction is catalyzed by CGS. An additional objective was to develop a transformation system for Berseem clover, and to introduce the appropriate gene constructs into it with the goal of improving their methionine content. Genes for the 15kD zein along with the genes for either the 10kD or 18kD zein have been introduced into the same alfalfa plant both by sexual crosses and by re-transformation. Analysis of these zein co-expressors have shown that both the IOkD and 18kD zein levels go up 5 to 10 fold when co-expressed with the 15kD zein (Bagga et al., MS in preparation). Incubation of the leaves of transgenic alfalfa co-expressing the 15kD and 10kD zein genes, in the rumen of cows have shown that the zein proteins are stable in the rumen. To increase the level of zein accumulation in transgenic alfalfa different promoters have been used to drive the zein genes in alfalfa and we have concluded that the CaMV 35S promoter is superior to the other strong leaf -specific promoters. By feeding callus tissue of alfalfa plants co-expressing the 15kD and 10kD zein genes with methionine and its precursors, we have shown that the zein levels could be significantly enhanced by increasing the methionine pools. We have now introduced the CGS gene (from Arabidopsis; kindly provided to us by Dr. Leustek), into the 15kD zein transformants and experiments are in progress to check if the expression of the CGS gene indeed increases the level of zein accumulation in alfalfa. We were not successful in developing a transformation protocol for Berseem clover.
7
Locy, Robert D., Hillel Fromm, Joe H. Cherry e Narendra K. Singh. Regulation of Arabidopsis Glutamate Decarboxylase in Response to Heat Stress: Modulation of Enzyme Activity and Gene Expression. United States Department of Agriculture, gennaio 2001. http://dx.doi.org/10.32747/2001.7575288.bard.
Abstract (sommario):
Most plants accumulate the nonprotein amino acid, g-aminobutyric acid (GABA), in response to heat stress. GABA is made from glutamate in a reaction catalyzed by glutamate decarboxylase (GAD), an enzyme that has been shown by the Israeli PI to be a calmodulin (CaM) binding protein whose activity is regulated in vitro by calcium and CaM. In Arabidopsis there are at least 5 GAD genes, two isoforms of GAD, GAD1 and GAD2, are known to be expressed, both of which appear to be calmodulin-binding proteins. The role of GABA accumulation in stress tolerance remains unclear, and thus the objectives of the proposed work are intended to clarify the possible roles of GABA in stress tolerance by studying the factors which regulate the activity of GAD in vivo. Our intent was to demonstrate the factors that mediate the expression of GAD activity by analyzing the promoters of the GAD1 and GAD2 genes, to determine the role of stress induced calcium signaling in the regulation of GAD activity, to investigate the role of phosphorylation of the CaM-binding domain in the regulation of GAD activity, and to investigate whether ABA signaling could be involved in GAD regulation via the following set of original Project Objectives: 1. Construction of chimeric GAD1 and GAD2 promoter/reporter gene fusions and their utilization for determining cell-specific expression of GAD genes in Arabidopsis. 2. Utilizing transgenic plants harboring chimeric GAD1 promoter-luciferase constructs for isolating mutants in genes controlling GAD1 gene activation in response to heat shock. 3. Assess the role of Ca2+/CaM in the regulation of GAD activity in vivo in Arabidopsis. 4. Study the possible phosphorylation of GAD as a means of regulation of GAD activity. 5. Utilize ABA mutants of Arabidopsis to assess the involvement of this phytohormone in GAD activation by stress stimuli. The major conclusions of Objective 1 was that GAD1 was strongly expressed in the elongating region of the root, while GAD2 was mainly expressed along the phloem in both roots and shoots. In addition, GAD activity was found not to be transcriptionally regulated in response to heat stress. Subsequently, The Israeli side obtained a GAD1 knockout mutation, and in light of the objective 1 results it was determined that characterization of this knockout mutation would contribute more to the project than the proposed Objective 2. The major conclusion of Objective 3 is that heat-stress-induced changes in GAD activity can be explained by heat-stress-induced changes in cytosolic calcium levels. No evidence that GAD activity was transcriptionally or translationally regulated or that protein phosphorylation was involved in GAD regulation (objective 4) was obtained. Previously published data by others showing that in wheat roots ABA regulated GABA accumulation proved not to be the case in Arabidopsis (Objective 5). Consequently, we put the remaining effort in the project into the selection of mutants related to temperature adaptation and GABA utilization and attempting to characterize events resulting from GABA accumulation. A set of 3 heat sensitive mutants that appear to have GABA related mutations have been isolated and partially characterized, and a study linking GABA accumulation to growth stimulation and altered nitrate assimilation were conducted. By providing a better understanding of how GAD activity was and was not regulated in vivo, we have ruled out the use of certain genes for genetically engineering thermotolerance, and suggested other areas of endeavor related to the thrust of the project that may be more likely approaches to genetically engineering thermotolerance.
8
Rafaeli, Ada, e Russell Jurenka. Molecular Characterization of PBAN G-protein Coupled Receptors in Moth Pest Species: Design of Antagonists. United States Department of Agriculture, dicembre 2012. http://dx.doi.org/10.32747/2012.7593390.bard.
Abstract (sommario):
The proposed research was directed at determining the activation/binding domains and gene regulation of the PBAN-R’s thereby providing information for the design and screening of potential PBAN-R-blockers and to indicate possible ways of preventing the process from proceeding to its completion. Our specific aims included: (1) The identification of the PBAN-R binding domain by a combination of: (a) in silico modeling studies for identifying specific amino-acid side chains that are likely to be involved in binding PBAN with the receptor and; (b) bioassays to verify the modeling studies using mutant receptors, cell lines and pheromone glands (at tissue and organism levels) against selected, designed compounds to confirm if compounds are agonists or antagonists. (2) The elucidation ofthemolecular regulationmechanisms of PBAN-R by:(a) age-dependence of gene expression; (b) the effect of hormones and; (c) PBAN-R characterization in male hair-pencil complexes. Background to the topic Insects have several closely related G protein-coupled receptors (GPCRs) belonging to the pyrokinin/PBAN family, one with the ligand pheromone biosynthesis activating neuropeptide or pyrokinin-2 and another with diapause hormone or pyrokinin-1 as a ligand. We were unable to identify the diapause hormone receptor from Helicoverpa zea despite considerable effort. A third, related receptor is activated by a product of the capa gene, periviscerokinins. The pyrokinin/PBAN family of GPCRs and their ligands has been identified in various insects, such as Drosophila, several moth species, mosquitoes, Triboliumcastaneum, Apis mellifera, Nasoniavitripennis, and Acyrthosiphon pisum. Physiological functions of pyrokinin peptides include muscle contraction, whereas PBAN regulates pheromone production in moths plus other functions indicating the pleiotropic nature of these ligands. Based on the alignment of annotated genomic sequences, the primary and secondary structures of the pyrokinin/PBAN family of receptors have similarity with the corresponding structures of the capa or periviscerokinin receptors of insects and the neuromedin U receptors found in vertebrates. Major conclusions, solutions, achievements Evolutionary trace analysisof receptor extracellular domains exhibited several class-specific amino acid residues, which could indicate putative domains for activation of these receptors by ligand recognition and binding. Through site-directed point mutations, the 3rd extracellular domain of PBAN-R was shown to be critical for ligand selection. We identified three receptors that belong to the PBAN family of GPCRs and a partial sequence for the periviscerokinin receptor from the European corn borer, Ostrinianubilalis. Functional expression studies confirmed that only the C-variant of the PBAN-R is active. We identified a non-peptide agonist that will activate the PBAN-receptor from H. zea. We determined that there is transcriptional control of the PBAN-R in two moth species during the development of the pupa to adult, and we demonstrated that this transcriptional regulation is independent of juvenile hormone biosynthesis. This transcriptional control also occurs in male hair-pencil gland complexes of both moth species indicating a regulatory role for PBAN in males. Ultimate confirmation for PBAN's function in the male tissue was revealed through knockdown of the PBAN-R using RNAi-mediated gene-silencing. Implications, both scientific and agricultural The identification of a non-peptide agonist can be exploited in the future for the design of additional compounds that will activate the receptor and to elucidate the binding properties of this receptor. The increase in expression levels of the PBAN-R transcript was delineated to occur at a critical period of 5 hours post-eclosion and its regulation can now be studied. The mysterious role of PBAN in the males was elucidated by using a combination of physiological, biochemical and molecular genetics techniques.
9
Fluhr, Robert, e Maor Bar-Peled. Novel Lectin Controls Wound-responses in Arabidopsis. United States Department of Agriculture, gennaio 2012. http://dx.doi.org/10.32747/2012.7697123.bard.
Abstract (sommario):
Innate immune responses in animals and plants involve receptors that recognize microbe-associated molecules. In plants, one set of this defense system is characterized by large families of TIR–nucleotide binding site–leucine-rich repeat (TIR-NBS-LRR) resistance genes. The direct interaction between plant proteins harboring the TIR domain with proteins that transmit and facilitate a signaling pathway has yet to be shown. The Arabidopsis genome encodes TIR-domain containing genes that lack NBS and LRR whose functions are unknown. Here we investigated the functional role of such protein, TLW1 (TIR LECTIN WOUNDRESPONSIVE1). The TLW1 gene encodes a protein with two domains: a TIR domain linked to a lectin-containing domain. Our specific aim in this proposal was to examine the ramifications of the TL1-glycan interaction by; A) The functional characterization of TL1 activity in the context of plant wound response and B) Examine the hypothesis that wounding induced specific polysaccharides and examine them as candidates for TL-1 interactive glycan compounds. The Weizmann group showed TLW1 transcripts are rapidly induced by wounding in a JA-independent pathway and T-DNA-tagged tlw1 mutants that lack TLW1 transcripts, fail to initiate the full systemic wound response. Transcriptome methodology analysis was set up and transcriptome analyses indicates a two-fold reduced level of JA-responsive but not JA-independent transcripts. The TIR domain of TLW1 was found to interact directly with the KAT2/PED1 gene product responsible for the final b-oxidation steps in peroxisomal-basedJA biosynthesis. To identify potential binding target(s) of TL1 in plant wound response, the CCRC group first expressed recombinant TL1 in bacterial cells and optimized conditions for the protein expression. TL1 was most highly expressed in ArcticExpress cell line. Different types of extraction buffers and extraction methods were used to prepare plant extracts for TL1 binding assay. Optimized condition for glycan labeling was determined, and 2-aminobenzamide was used to label plant extracts. Sensitivity of MALDI and LC-MS using standard glycans. THAP (2,4,6- Trihydroxyacetophenone) showed minimal background peaks at positive mode of MALDI, however, it was insensitive with a minimum detection level of 100 ng. Using LC-MS, sensitivity was highly increased enough to detect 30 pmol concentration. However, patterns of total glycans displayed no significant difference between different extraction conditions when samples were separated with Dionex ICS-2000 ion chromatography system. Transgenic plants over-expressing lectin domains were generated to obtain active lectin domain in plant cells. Insertion of the overexpression construct into the plant genome was confirmed by antibiotic selection and genomic DNA PCR. However, RT-PCR analysis was not able to detect increased level of the transcripts. Binding ability of azelaic acid to recombinant TL1. Azelaic acid was detected in GST-TL1 elution fraction, however, DHB matrix has the same mass in background signals, which needs to be further tested on other matrices. The major findings showed the importance of TLW1 in regulating wound response. The findings demonstrate completely novel and unexpected TIR domain interactions and reveal a control nexus and mechanism that contributes to the propagation of wound responses in Arabidopsis. The implications are to our understanding of the function of TIR domains and to the notion that early molecular events occur systemically within minutes of a plant sustaining a wound. A WEB site (http://genome.weizmann.ac.il/hormonometer/) was set up that enables scientists to interact with a collated plant hormone database.
10
Shpigel, Muki, Allen Place, William Koven, Oded (Odi) Zmora, Sheenan Harpaz e Mordechai Harel. Development of Sodium Alginate Encapsulation of Diatom Concentrates as a Nutrient Delivery System to Enhance Growth and Survival of Post-Larvae Abalone. United States Department of Agriculture, settembre 2001. http://dx.doi.org/10.32747/2001.7586480.bard.
Abstract (sommario):
The major bottlenecks in rearing the highly priced gastropod abalone (Haliotis spp.) are the slow growth rate and the high mortality during the first 8 to 12 weeks following metamorphosis and settling. The most likely reason flor these problems is related to nutritional deficiencies in the diatom diet on which the post larvae (PL) feed almost exclusively in captivity. Higher survival and improved growth rate will reduce the considerable expense of hatchery-nursery resisdence time and thereflore the production costs. BARD supported our research for one year only and the support was given to us in order to prove that "(1) Abalone PL feed on encapsulated diatoms, and (2) heterotrophic diatoms can be mass produced." In the course of this year we have developed a novel nutrient delivery system specifically designed to enhance growth and survival of post-larval abalone. This approach is based on the sodium-alginate encapsulation of heterotrophically grown diatoms or diatom extracts, including appetite-stimulating factors. Diatom species that attract the PL and promote the highest growth and survival have been identified. These were also tested by incorporating them (either intact cells or as cell extracts) into a sodium-alginate matrix while comparing the growth to that achieved when using diatoms (singel sp. or as a mixture). A number of potential chemoattractants to act as appetite-stimulating factors for abalone PL have been tested. Preliminary results show that the incorporation of the amino acid methionine at a level of 10-3M to the sodim alginate matrix leads to a marked enhancement of growth. The results ol these studies provided basic knowledge on the growth of abalone and showed that it is possible to obtain, on a regular basis, survival rates exceeding 10% for this stage. Prior to this study the survival rates ranged between 2-4%, less than half of the values achieved today. Several diatom species originated from the National Center for Mariculture (Nitzchia laevis, Navicula lenzi, Amphora T3, and Navicula tennerima) and Cylindrotheca fusiformis (2083, 2084, 2085, 2086 and 2087 UTEX strains, Austin TX) were tested for heterotrophic growth. Axenic colonies were initially obtained and following intensive selection cycles and mutagenesis treatments, Amphora T3, Navicula tennerima and Cylindrotheca fusiformis (2083 UTEX strain) were capable of growing under heterotrophic conditions and to sustain highly enriched mediums. A highly efficient selection procedure as well as cost effective matrix of media components were developed and optimized. Glucose was identified as the best carbon source for all diatom strains. Doubling times ranging from 20-40 h were observed, and stable heterotroph cultures at a densities range of 103-104 were achieved. Although current growth rates are not yet sufficient for full economical fermentation, we estimate that further selections and mutagenesis treatments cycles should result in much faster growing colonies suitable for a fermentor scale-up. As rightfully pointed out by one of the reviewers, "There would be no point in assessing the optimum levels of dietary inclusions into micro-capsules, if the post-larvae cannot be induced to consume those capsules in the first place." We believe that the results of the first year of research provide a foundationfor the continuation of this research following the objectives put forth in the original proposal. Future work should concentrate on the optimization of incorporation of intact cells and cell extracts of the developed heterotrophic strains in the alginate matrix, as well as improving this delivery system by including liposomes and chemoattractants to ensure food consumption and enhanced growth.