http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/92 Sun, 12 Apr 2026 22:15:28 GMT 2026-04-12T22:15:28Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/88130 標題: 黑色素前驅物控制阿拉伯芥鐵的吸收; Melanin precursors control Arabidopsis Fe uptake 作者: 廖小惟; Siao-Wei Liao 摘要: 不論對於動物或是植物而言，鐵都是十分重要的金屬元素。缺鐵性貧血 (Iron Deficiency Anemia, IDA)是世界上很普遍的健康問題，造成IDA的其中一個重要原因是世界主要農作物中缺乏鐵。本研究目的旨在利用生物刺激素 (biostimulant) 提升植物吸收鐵的能力以及植物種子中的鐵含量，做為增加作物鐵吸收的前期試驗。本實驗研究的生物刺激素為黑色素的前驅物左旋多巴 ( L-3,4-dihydroxyphenylalanine, L-DOPA)。經過水耕試驗，可以發現L-DOPA雖然具有植物相剋物質 (allelopathic compound) 的特性，卻能有效的提升阿拉伯芥根部吸收鐵的能力，並且能力提升隨著施用濃度而上升。不過，完全氧化的L-DOPA在水耕環境中並不能促進根部鐵吸收。另一方面，土耕試驗結果顯示，澆灌3 mM的 L-DOPA時阿拉伯芥種子中的鐵含量可以達到控制組的三倍之多。此外，黑色素生成路徑中除了L-DOPA的其他的前驅物(皆為indolic compounds)也能夠影響阿拉伯芥的鐵吸收能力，其影響如下述：當適量供應這些indolic compounds且環境中的鐵充足時，阿拉伯芥的鐵吸收能力增加；反之在鐵缺乏時，阿拉伯芥的鐵吸收能力則會遭到抑制。這些結果顯示，黑色素生合成路徑上之各類化合物能顯著的影響阿拉伯芥體內鐵的動態平衡，於提升作物鐵含量之應用上具成為生物刺激素的發展潛力。; Fe is an important metallic element for both animals and plants. Fe deficiency anemia (IDA) is a common health problem worldwide, and one of the fundamental causes is the lack of Fe in the world's major crops. The purpose of this study is to use a biostimulant to enhance the ability of plants to absorb Fe and increase the Fe content in plant seeds as a preliminary test for increasing crop Fe absorption. The biostimulant studied in this thesis is L-3,4-dihydroxyphenylalanine (L-DOPA), the precursor of melanin. Through hydroponic experiments, it was found that although L-DOPA has allelopathic properties, it can effectively enhance the capability of Arabidopsis roots to absorb Fe, and the capability to absorb Fe increases with the concentration applied. However, fully oxidized L-DOPA cannot promote root Fe absorption in hydroponic environments. On the other hand, soil-based experiments showed that watering with 3 mM of L-DOPA increase the Fe content in Arabidopsis seeds to more than three folds that of the control group. In addition, other precursors of melanin in the melanin biosynthetic pathway (two of which are indolic compounds) can also affect the Fe absorption ability of Arabidopsis. When these indolic compounds are supplied in moderation with sufficient Fe in the environment, the Fe absorption ability of Arabidopsis increases; otherwise when Fe is lacked, the Fe absorption ability is inhibited. These results suggest that various compounds in the melanin biosynthetic pathway can significantly affect the homeostasis of Fe in Arabidopsis and have the potential to become a biostimulant for increasing crop Fe content. Sun, 01 Jan 2023 00:00:00 GMT http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/88130 2023-01-01T00:00:00Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/40982 標題: 麵粉性質對法國麵包烘焙品質之影響; Effects of Flour Quality on the Baking Characteristics of French Bread 作者: Kuen-Ho Shih; 施坤河 摘要: 本論文主要探討市售法國麵包專用麵粉與來自粉道配粉的麵粉之理化性質對法國麵包製作及產品品質的影響。試驗主要分為兩部分：首先探討四種市售法國麵包專用麵粉（麵粉A、B、C及D）的的理化性質及其烘焙品質，接著探討三種由粉道配粉而得之麵粉（麵粉H、M及L）的理化性質對法國麵包品質的影響。結果顯示，四種市售法國麵包專用粉中，麵粉A及B的蛋白質、濕筋及 F1*之含量、%UPP、Extensograph抗延展性（R）值較麵粉C及D高，Farinograph擴展時間及攪拌穩定性的時間亦較麵粉C及D長，攪拌耐受指數則較麵粉C及D低。麵粉A及B所製作之麵包，其比容積及形狀比（form ratio）較麵粉C及D大。較特殊的為麵粉D，其蛋白質含量最低，但麵筋指數卻最高，此與其麵粉中高分子量之麥穀蛋白(F1*及F1)含量較多有關，此亦反應出麵粉D麵糰於SMS D/R吹泡試驗時，其P及W值最高。因此，即使後發酵時間較長時，麵包形狀比、比容積均可以與蛋白質含量較高的麵粉A或B相似。感官品評試驗結果顯示，圓形硬式麵包及棒槌狀法國麵包分別以市售麵粉A及D之整體接受度為最佳。三種由粉道配粉而得之麵粉規格設定於灰分與蛋白質有明顯的區分，麵粉H之灰分含量最高（0.72%），其蛋白質及濕筋含量亦最高，但其%UPP含量、抗延展性則最低，擴展時間較短、攪拌穩定性較差；後發酵時間較長 (＞ 60 min) 時，麵包體積不增加且形狀比變小。麵粉L之灰分含量最低（0.33%），蛋白質及濕筋含量亦最低，但是麵筋指數、%UPP及抗延展性最高，擴展時間及攪拌穩定性的時間亦最長；但製作之麵包體積最小、形狀比最大。麵粉L之蛋白質之質及發酵耐性都很好，但需要較長的後發酵時間(＞ 90 min)，否則體積不大，麵包硬度高。麵粉M之理化性質介於麵粉H及L之間，其具有與市售麵粉A相近之濕筋含量、麵筋指數及%UPP，麵糰攪拌性質及產品形狀比亦接近於市售麵粉A之產品。本試驗中麵筋指數、F1* 、F1及% UPP可以作為麵粉蛋白質質的指標，與麵包製作之後發酵麵糰耐性及麵包體積有良好之相關性。; The purpose of this study was to investigate the physicochemical and baking properties of wheat flours obtained from 4 commercial French bread specialty flours (flour A, B, C, and D) and 3 flours blended from flour streams (flour H, M, and L). The results showed that the protein, wet gluten and F1* content, %UPP, Extensograph R value were higher in flour A and B than flour C and D. Breads made from flour A and B had higher specific volume and form ratio than those made from flour C and D. Among four commercial flours, flour D was unique in its high gluten index but low protein content. This was attributed to its high ratio of high molecular weight glutenin (F1* and F1). The unique protein quality of flour D contributed to the high P and W values of SMS D/R inflation test. This characteristic also reflected to the good specific volume and form ratio of bread made by long proofing time. The round hearth bread made form flour A and Baguette made from flour D had the highest scores in overall acceptance of sensory evaluation. The three flours obtained from stream-blended flours were significant different in their ash and protein contents. Flour H had high ash, protein and wet gluten content with low %UPP, less resistant and dough stability and short developing time. The breads made by long proofing time (> 60 min) had low volume and small form ratio. On the contrary, flour L contained low ash, protein and wet gluten, but high gluten index, %UPP, Farinograph and R valure. The flour L had long developing time and good dough stability, however, the breads made from this flour was small in volume and high in form ratio and hard in texture. The long proofing time (> 90 min) was required for improving the bread volume and texture made from flour L. Flour M owned the properties between flour L and H and had the similar chemical composition (wet gluten content, gluten index and %UPP), dough property (dough stability) and bread quality (form ratio) with flour A. According to the results in this study, the gluten index, F1*, F1 and %UPP values could be used as the protein quality index of wheat flour for hearth bread and French bread mainly. Tue, 01 Jan 2008 00:00:00 GMT http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/40982 2008-01-01T00:00:00Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/71227 標題: 麵包蟲中腸分離菌株Pseudomonas nitroreducens之酯酶特性分析 ; Characterization of an esterase of Pseudomonas nitroreducens from Tenebrio molitor mid-gut 作者: Jung-En Kuan; 關榮恩 摘要: 本研究取麵包蟲(Tenebrio molitor)中腸道段中的共生菌，以甘油三丁酸酯作為單一碳源培養，篩選出可能帶有脂肪酶之菌株，將所得之菌種用16s核醣體去氧核醣核酸(16s rDNA)作為鑑定標準，比對資料庫並使用比對分析後知其為Pseudomonas nitroreducens，再從物種Pseudomonas nitroreducens的蛋白質資料庫中尋找可能為脂肪酶之α/β水解酶，以帶有限制酶酵素的切位和組胺酸標記的候選引子進行聚合酶連鎖反應，經限制酵素、接合酵素反應，建構以pET21a質體為載體的重組質體，以轉型作用送入大腸桿菌BL21(DE3)中用異丙基-β-D-硫代辦乳糖苷(IPTG)誘導，續用親和性管柱進行純化，發現洗脫後重組蛋白質可在甘油三丁酸(tributyrin)洋菜膠盤上產生降解圈。將純化過後的重組蛋白質進行酵素活性測試，以具有不同碳鍊長度的對─硝基苯酚酯類 (p-nitrophenyl ester)作為受質，偵測波長405 nm的吸光值來計算受質的分解狀況，藉此推估酵素活性。經實驗數據，重組蛋白質在溫度40℃、pH 8 時具有最高活性，且對於丁酸對─硝基苯酚酯 (p-nitrophenyl butyrate)分解效率最佳，在熱穩定性實驗中，當處理溫度大於50℃時，其活性下降劇烈。離子對活性影響分析中發現MgCl2和NH4Cl可提高酵素活性，MnSO4、NiSO4、CaCl2、ZnSO4、CoCl2、CuSO4、FeSO4、FeCl3 則會使活性降低，NaCl 則對於活性沒有顯著性的影響。有機溶劑和界面活性劑的添加方面，發現DMSO (Dimethyl sulfoxide)可幫助提升酵素活性，正己烷 (Hexane)、甲醇 (Methanol)、乙醇 (Ethanol)、丙酮 (Acetone)、異丙醇 (Isopropanol)、三氯甲烷 (Chloroform)、乙酸乙酯 (Ethyl acetate)會降低酵素活性，而甘油 (Glycerol)則不會對酵素有顯著的影響，界面活性劑方面，Triton x-100、Tween 80、 Tween 20、Brij35等界面活性劑皆會使酵素活性減少。經Lineweaver-Burk雙倒數作圖法，可得出之Km 值為0.488 (mM)，Vmax為0.0644 (mM/min)， kcat為3.01 (s-1)，kcat / Km為6.17 (mM-1/s-1)。之後，經脂肪酶親緣性分析，LipD為第四型脂肪酶，為此蛋白質的分類依據，並探討其所具有之獨特的特性。; In this study, a symbiotic bacteria from yellow mealworm’s (Tenebrio molitor) mid-gut was isolated with characteristics of growth on minimal-tributyrin medium. After a PCR-amplification of its 16s rDNA, the resultant nucleotide sequences were then analyzed by schemes of the phylogeny trees. Accordingly, it was designated as Pseudomonas nitroreducens D-01. Next, by searching the lipolytic enzymes in its protein data bank, one of those potential lipolytic α/β hydrolases was identified, again using PCR-amplification and nucleotide-sequencing methods. To construct an expression of this lipolytic gene in plasmids, the target-gene primers were then designed, carrying the C-terminal his-tag sequences. Using the vector pET21a, a recombinant lipolytic hydrolase D gene with his-tag nucleotides was successfully cloned into it, of which the lipolytic D gene is under a control of the T7 promoter. After transformation of the resultant plasmids into Eescherichia coli BL21 (DE3), an IPTG inducer was used for the induction of the recombinant proteins. The protein products were then purified by metal-ion affinity column and the purified proteins were found capable of forming a clear zone on tributyrin agar plate. Shortly, its enzyme activities were determined by degradation of p-nitrophenyl ester(s) and the substantial yellow end-product, p-nitrophenol, was measured at O.D.405 nm. Specifically, this lipolytic enzyme efficiently targets p-nitrophenyl butyrate. As well, it shows the most reactive activities at 40℃, pH 8 in potassium phosphate buffer. In thermal stability assays, the activities of this enzyme dramatically drop when the temperature is above 50℃. In metal ion assays, MgCl2 and NH4Cl induce the enzyme activities while MnSO4, NiSO4, CaCl2, ZnSO4, CoCl2, CuSO4, FeSO4, and FeCl3 reduce its activities. Besides, NaCl has no effects on its enzyme activities. Most organic solvents decrease the activities of this enzyme such as hexane, methanol, ethanol, acetone, isopropanol, chloroform and ethyl acetate. However, its enzyme activities increase when DMSO exists. All the surfactants like Triton X-100, Tween 80, Tween 20, and Brij35 decrease its lipolytic activities. Using Lineweaver-Burk double reciprocal methods, the function of the enzyme kinetics were determined such as Km = 0.488 (mM), Vmax = 0.0644 (mM/min), and kcat = 3.01 (s-1), as well the total efficiency of kcat / Km is 6.17 (mM-1/s-1). Afterwards, based on the phylogenetic analyses, this lipolytic protein is classified to type IV lipase by its homologous conserved region in this lipase family. Wed, 01 Jan 2020 00:00:00 GMT http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/71227 2020-01-01T00:00:00Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/78590 標題: 鹵素離子對光催化劑降解磺胺甲噁唑之影響與機制; The effect and mechanism of halide ions on the photocatalytic degradation of sulfamethoxazole by photocatalysts 作者: 歐明翰; Ming-Han Ou 摘要: 氧化鎢(tungsten trioxide, WO3)、二氧化鈦(titanium dioxide, TiO2)以及氧化鋅(zinc oxide, ZnO)奈米顆粒(nanoparticles, NPs)等均具無毒、高穩定性以及高反應性等優點，本篇以此三種顆粒作為光催化材料。磺胺甲噁唑(Sulfamethoxazole, SMZ)為一種臨床上常見的磺胺類抗生素，然而其廣泛使用導致SMZ流布至環境水體當中，且當前廢水處理與微生物降解SMZ均無法有效移除之，光催化降解被視為最快速有效移除SMZ的方法之一。水體中的常見鹵素離子對光降解可能有正向或負向的影響，本研究則關注於其與不同光催化劑的互動。隨著氯與溴離子濃度的提高，WO3、商用TiO2 (commercial TiO2, CTiO2)以及ZnO NPs聚集與沉降的現象逐步明顯。無鹽類情況下，三者降解SMZ之速率常數分別為0.0081、0.0065以及0.022 min-1。當系統中存在氯離子，其可能於過程中轉為自由基捕捉者，導致WO3與ZnO NPs對SMZ的降解能力減弱。然而CTiO2提供的酸性環境 (pH 4.4 to 4.6 )，可將其轉為活性鹵素物種，可於500 mM NaCl下提高降解速率至0.023 min-1。溴離子同樣使WO3對SMZ的降解能力減弱。然而在500 mM NaBr下，CTiO2與ZnO的降解速率明顯提高至0.21 min-1與0.056 min-1。此些促進的原因可能來自於活性鹵素物種的生成，其生成又與環境的酸鹼值、顆粒表面電荷以及光催化劑的量子產率等有關，故本研究目的為證明鹵素鹽類促進SMZ降解的原因與其機制。光致激發光譜中，高濃度NaBr下可明顯降低CTiO2與ZnO電子電洞對的重組，因而增加催化能力。以coumarin與courmain-3-carboxylic acid (CCA)分別測定溶液中與顆粒表面的•OH，在無鹽類的情況下均可測定到此二者。然而系統中含NaBr的情況下，則無法測得，顯示溴離子會與•OH發生反應。另外藉自由基捕捉的實驗顯示，在含有NaBr的情況下，不論系統是否有•OH清除劑 (methanol)，SMZ的降解均被提升，顯示•OH對其降解影響較小。但系統中具電洞清除劑 (sodium oxalate, Na2C2O4)的情況下，則均會明顯抑制SMZ的降解，顯示活性鹵素物種的形成與電洞息息相關。此外allyl alcohol (AA)作為顆粒表面活性物種(•OH、•Br等)的捕捉者，tert-butyl alcohol (t-BuOH)作為溶液中活性物種的捕捉者的實驗中，CTiO2與ZnO的光催化反應均會被抑制。然而當系統中含有NaBr時，加入AA組具有明顯的抑制，而t-BuOH組則無，證明活性物種應大量存在於顆粒表面。本篇中也藉由N,N-diethyl-p-phenylenediamine (DPD)實驗，證實CTiO2與ZnO於紫外光下可將溴離子反應為活性鹵素物種。而cyclohexene會與Br2反應形成dibromocyclohexane，同時也證實Br2會於系統中生成。在上述兩實驗中，若添加甲醇則會抑制活性溴物種的產量，顯示出其生成亦受到•OH的影響。最後以HPLC-MS分析降解副產物，發現兩種SMZ的溴化產物。分別為在苯環或胺基上接上一個溴，與在苯環位置接上兩個溴。此結果亦直接證明系統中的溴離子將被反應成為一高活性的物種，並具有攻擊SMZ的能力。; Tungsten trioxide (WO3), titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) are chosen as photocatalysts in this study. The widespread detection of antibiotics in aquatic environments is raising public health concerns. Sulfamethoxazole (SMZ) was chosen as a target compound because it is one antibiotic extensively applied in human and animals. Photocatalysis is regarded as a green technology to treat the wastewater with SMZ. The presence of halide anions which are common in the water body has both positive and negative influence on the photocatalytic performance. This study aims to investigate the photocatalytic degradation mechanism of SMZ by different photocatalysts with the presence of halide salts. With the increase of chloride or bromide concentration, the aggregation and sedimentation of WO3, commercial TiO2 (CTiO2) and ZnO NPs become more significantly. In the condition without electrolytes, the rate constants of SMZ photodegradation were 0.0081, 0.0065 and 0.022 min-1, respectively. Chloride ions in the systems might scavenge active radicals during the photocatalytic reactions, hence the photodegradation efficiency of SMZ by WO3 and ZnO decreased. However, UV/CTiO2 system provided an acid condition (pH 4.4 to 4.6) to transform chloride ions to reactive halogen species (RHS), thus increased the removal rate constant to 0.023 min-1 in the presence of 500 mM NaCl. When there were bromide ions, the degradation rate of SMZ by WO3 decreased, while the rate constants in UV/CTiO2 and UV/ZnO systems enhanced to 0.21 and 0.056 min-1, respectively. The enhancement of degradation could be attributed to the generation of RHS which were relative to the pH in the systems, particle surface charges and quantum yields of photocatalyst. This study studied why the photodegradation of SMZ enhanced with halide ions. First, with a high NaBr concentration (≥100 mM), the decrease in the intensity of photoluminescence (PL) peaks was observed, which depicted less charge recombination in the presences of NaBr. Second, dissolved and surface hydroxyl radicals (•OH) measured by coumarin and coumarin-3-carboxylic acid, respectively, were both increased gradually during photocatalytic process, but were both totally suppressed with the addition of NaBr, elucidating that bromide ion could react with •OH. Third, after adding different oxidants scavengers, methanol (•OH scavenger), allyl alcohol (AA) (surface-bound oxidants scavenger) and tert-butyl alcohol (t-BuOH) (dissolved oxidants scavenger), the photodegradation of SMZ was inhibited in absence of NaBr; however, SMZ could be removed after NaBr addition, implying the existence of RHS that was generated more on the surface of CTiO2 or ZnO because the inhibition of degradation by AA was much more significant than t-BuOH. Besides, it was further confirmed that the creation of these RHS should be more relative to photogenerated hole than •OH because the degradation rate of SMZ significantly reduced in the presence of Na2C2O4, hole scavenger, whether there was NaBr or not. Furthermore, the results of N,N-diethyl-p-phenylenediamine tests depicted RHS generated in both UV/ CTiO2 and UV/ZnO systems with NaBr. By the cyclohexene test, the production of bromide on the surface of CTiO2 and ZnO with NaBr was confirmed by dibromocyclohexane. Moreover, RHS generation was influenced by the amount of •OH, hence RHS yields decreased in the presence of methanol. RHS can react with unsaturated bonds and electron-rich moieties such as aromatic rings to form halogenated products. There were two halogenated byproducts, mono- and di-brominated derivatives of SMZ in the photodegradation process of SMZ by CTiO2 and ZnO in the presence of NaBr, confirmed by HPLC-MS. Tue, 01 Jan 2019 00:00:00 GMT http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/78590 2019-01-01T00:00:00Z