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探究不同富里酸质量浓度对三角褐指藻二十碳五烯酸(EPA)合成积累的影响。结果表明,在质量浓度20 mg/L富里酸诱导下,三角褐指藻EPA含量和产量均达到最大值,为19.81 g/100 g和738.91 mg/L,较无富里酸诱导EPA含量和产量分别提高1.12和1.50倍。外源富里酸作用提高了三角褐指藻胞内过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的酶活,使色素(叶绿素、类胡萝卜素)和总多酚抗氧化组分比例增加,活性氧(ROS)和丙二醛(MDA)水平降低,整体抗氧化能力获得显著提升,有效阻抑EPA的氧化分解;富里酸作用同时还上调了EPA合成通路去饱和酶(Δ5-FADS、Δ6-FADS、Δ12-FADS、Δ15-FADS、Δ17-FADS)和延长酶(Δ6-ELOVL)等系列关键酶,使其上调表达量较无富里酸作用分别增加0.33、0.94、0.33、0.58、1.15和0.70倍,为EPA高效合成积累提供前驱物和能量。 相似文献
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营养元素对三角褐指藻生长和脂类积累的影响 总被引:1,自引:0,他引:1
研究了不同营养元素(氮、磷、硅、铁)在不同培养浓度条件下,对三角褐指藻生长以及细胞脂类积累的影响作用。结果显示:藻细胞生长随氮含量的增加而增加,但超过一定浓度后作用不明显,最适合三角褐指藻生长的氮含量为 1.76 mmol/L。缺氮和低氮(0.22~0.44 mmol/L)培养能够明显提高藻细胞脂类含量。缺磷培养能有效促进藻株脂类积累,但是藻细胞生长受到明显抑制。缺硅导致藻细胞的生长减缓,但是对藻细胞的油脂积累影响不显著。在缺铁和高铁(0.048 mmol/L)条件下,藻的总脂含量均高于正常的培养条件。实验证明通过两步培养的方法,先在营养充足的培养基中进行藻细胞生长,然后将藻细胞转移到海水中培养,可以明显提高藻细胞的油脂含量。最终本实验确定海水为诱导三角褐指藻脂类积累的最佳诱导培养基。 相似文献
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以优良藻株胶球藻Coccomyxa subellipsoidea C-169为受试对象,探究不同二乙醇胺(DEA)浓度对胶球藻固定CO2及积累油脂的影响。结果表明,适宜浓度DEA可显著提高胶球藻固定CO2和积累油脂效率。在40mg/L DEA条件下,胶球藻生物量、CO2固定效率、油脂含量、油脂产率均达到最大值为0.97g/L、225.98mg/(L·d)、64.33%、59.9mg/(L·d),分别较无DEA对照提高了1.64倍、1.64倍、1.15倍和1.27倍。外源DEA作用提高了体系气液传质系数,增强CO2传质效率,使得胶球藻可用无机碳源比例增加,同时上调固碳路径Rubisco和CA加强胶球藻固定CO2,上调脂肪酸路径ACCase以及下调ACCase竞争路径PEPC为油脂合成积累提供前体和能量,从而协同强化了胶球藻固定CO2和积累油脂。本文研究结果为工业化胶球藻CO2生物减排及可再生能源开发提供依据。 相似文献
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二十碳五烯酸(eicosapentaenoic acid,EPA)因具有调节血脂、降低纤维蛋白、预防心血管疾病以及抗炎抗过敏的生理功能,被广泛应用于食品、医疗、化妆品以及饲料添加等领域。目前,EPA的需求日益增加,但是富含多不饱和脂肪酸(polyunsaturated fatty acids,PUFAs)的鱼油等自然资源逐渐匮乏,利用改造的微生物菌种发酵生产EPA的方式成为主要趋势。本研究利用同源重组技术将Shewanella sp. SCRC2738的烯酰还原酶基因(enoyl-reductase,sh-ER)分别敲入Schizochytrium limacinum SR21的ORFB-ER和ORFC-ER基因中,调控多不饱和脂肪酸合成的偏好性以提高EPA的产量。研究表明,sh-ER替换ORFB-ER基因的重组菌株(B-sh-ER)中EPA含量提高了85.7%,聚酮合酶(polyketide synthases,PKS)途径相关基因转录水平明显上调。而sh-ER替换ORFC-ER基因的重组菌株(C-sh-ER) 中PUFAs合成基本不变。在5 L发酵罐中放大培养后,B-sh-ER重组菌株总油脂提高28.7%,达到73.2 g/L;EPA产量提高71.6%,达到732.4 mg/L。本研究为促进裂殖壶菌PUFAs高产提供了新的策略,同时也为调控裂殖壶菌合成EPA提供了新的视角。 相似文献
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通气量和CO2对Nannochloropsis sp.在光生物反应器中的生长和EPA合成的影响 总被引:4,自引:0,他引:4
实验考察了在气升式内环流光生物反应器中通气量、CO2含量等培养条件对Nannochloropsis sp.生长及EPA合成的影响. 结果表明,在气升式内环流光生物反应器中培养,Nannochloropsis sp.生长速率显著提高. 培养8 d,Nannochloropsis sp.生物量(干重)可达857 mg/L,是摇床培养的2倍. 在一定范围内,Nannochloropsis sp.的生长速率随通气量的增加而增加,在本实验条件下,通气量为500 mL/min时生长最快,而过高的通气量则对Nannochloropsis sp.的生长没有促进作用. 在通气中含1%(j) CO2时,可加快藻细胞的生长,最大生长速率可达不配加CO2时的1.8倍. 通气量和CO2对Nannochloropsis sp.细胞内总脂肪酸及EPA的积累有显著影响. 在通气量为400 mL/min及CO2含量为0.5%时,培养液中EPA产量最高,达到39.0 mg/L. 相似文献
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简要介绍了皮肤羰基化反应的诱因,重点从皮肤中蛋白质羰基化产生机理分析了其对人体肌肤产生的不良反应.讨论了蛋白质的降解系统,最后根据蛋白质的羰基化产生机理以及降解方式,提出建议解决方案:二葡糖基棓酸、玫瑰茄花提取物、欧洲酸樱桃花提取物可以通过降低ROS含量和三角褐指藻提取物提高20S酶体活性加速羰基化蛋白质水解水平降低人... 相似文献
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以不同粒度的白音华褐煤碱性煤浆为原料,5%(质量分数,下同)NaOH溶液和1 mol/L H2SO4溶液为pH值调节剂,制备胡敏酸和富里酸。通过容量法和紫外可见分光光度法分析胡敏酸和富里酸的含量、提取率、E4/E6值和DPPH(1,1-二苯基-2-三硝基苯肼)抗氧化活性,探讨褐煤粒度对胡敏酸和富里酸的影响规律。结果表明:当褐煤粒度减小到13.28μm时,胡敏酸和富里酸的总提取率为86.34%,胡敏酸与富里酸的分子量和芳香缩合度最为相似。该粒度条件下,富里酸的提取率可达62.28%,游离腐植酸质量分数为47.4%,DPPH自由基清除率为41.3%,富里酸的抗氧化活性显著。 相似文献
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《日用化学品科学》2004,(12)
仙婷(中国)有限公司代理的三角褐指藻提取物正式投放市场仙婷(中国)有限公司(SETHICCHINA)(www seth ic china.com)于2004年10月19日在广州正式宣布向市场投放三角褐指藻提取物(Thalassane) ,它是由克里斯汀 迪奥(ChristianDior)研究中心开发的微藻类提取物 ,其功效是使皮肤恢复到年轻时的状态。三角褐指藻提取物是通过一种新颖的作用机理发挥其功效的 ,那就是“泛素调节的蛋白质降解” ,也正是这个机理使其发现者(以色列科学家阿龙·切哈诺沃、阿夫拉姆·赫什科和美国科学家欧文·罗斯)在2004年10月6日获得了诺贝尔化学奖。在20世纪… 相似文献
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The oxidative stabilities of one canola oil and six soybean oils of various fatty acid compositions were compared in terms
of peroxide values, conjugated dienoic acid values and sensory evaluations. Two of the soybean oils (Hardin and BSR 101) were
from common commercial varieties. The other four soybean oils were from experimental lines developed in a mutation breeding
program at Iowa State University that included A17 with 1.5% linolenate and 15.2% palmitate; A16 with 2% linolenate and 10.8%
palmitate; A87-191039 with 2% linolenate and 29.6% oleate; and A6 with 27.5% stearate. Seed from the soybean genotypes was
cold pressed. Crude canola oil was obtained without additives. All oils were refined, bleached and deodorized under laboratory
conditions with no additives and stored at 60°C for 15 days. The A17, A16, A87-191039 and A6 oils were generally more stable
to oxidation than the commercial soybean varieties and canola oil as evaluated by chemical and sensory tests. Canola oil was
much less stable than Hardin and BSR 101 oils by both chemical and sensory tests. The peroxide values and flavor scores of
oils were highly correlated with the initial amounts of linolenate (r=0.95, P=0.001). Flavor quality and flavor intensity
had negative correlations with linolenate, (r=−0.89, P=0.007) and (r=−0.86, P=0.013), respectively. 相似文献
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生物柴油在精细化学品领域的应用 总被引:2,自引:0,他引:2
论述了生物柴油(即脂肪酸甲酯)代替脂肪酸在制造精细化工品上的优势,并列举了生物柴油在表面活性剂工业、塑料助剂、醇酸树脂、皮革化学品上的应用。指出了用生物柴油代替脂肪酸具有成本低廉、工艺简化的优点,并可提高生物柴油的应用价值,具有广阔的应用前景。 相似文献
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G. Márquez-Ruiz M. C. Pérez-Camino M. C. Dobarganes 《Journal of the American Oil Chemists' Society》1992,69(9):930-934
This study was designed to determine digestibilities of fatty acid monomers, dimers and polymers as components of diets containing
thermally oxidized oils. Male Wistar rats were fed semipurified diets supplemented with unheated, heated and a 1:1 mixture
of unheated/heated olive oils at 6, 12 and 20% w/w of diet. In a 14-d experimental period, fecal lipids were extracted and
analyzed by a combination of adsorption and high-performance size-exclusion chromatographies. Thus, it was possible to separate
and quantitate five groups of fatty acids—nonpolar monomers, oxidized monomers, nonpolar dimers, oxidized dimers and polymers.
Nonpolar fatty acid monomers showed high digestibilities, although significantly influenced by the alteration level of the
dietary oil. The apparent absorption of oxidized fatty acid monomers averaged 76.6%. Among polymeric fatty acids, the lowest
digestibilities were found for nonpolar dimers (10.9% on average), whereas oxidized dimers and polymers possessed higher apparent
absorbability than expected, ranging from 22.7% to 49.6%. Chemical modifications prior to absorption, leading to less complex
products, may have contributed to enhanced digestibility of polymers. 相似文献
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Christina Borch-Jensen Jørgen Mollerup 《Journal of the American Oil Chemists' Society》1996,73(9):1161-1164
Determination of the content of vernolic acid (12,13-epoxy-9c-octadecenoic) in the oil ofEuphorbia lagascae has been performed by gas chromatography of the fatty acid methyl ester derivatives of the triacylglycerols in the oil and
by supercritical fluid chromatography (SFC) of the raw oil and the fatty acid derivatives of the oil. The content of vernolic
acid was found to be 55 wt%. The three methods were compared, and SFC analysis of the fatty acid derivatives was found to
be the most accurate method. 相似文献
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Ken'ichi Ichihara Chihiro Kohsaka Yoshihiro Yamamoto Takehiro Masumura 《Journal of the American Oil Chemists' Society》2021,98(2):149-155
Free fatty acids (FFA) in crude rice oil were selectively and stoichiometrically derivatized to fatty acid N,N-dimethylamides (FADMA) by catalytic condensation at 45 °C, and then esterified fatty acids (eFA) were directly converted to fatty acid methyl esters (FAME) at 37 °C. The mixture of FADMA and FAME formed in a single test tube was injected into the capillary column of a gas chromatograph (GC). No mutual contamination occurred between FFA and eFA, and reliability of the method was confirmed by comparison between GC data obtained by this method and by a conventional isolation method. The advantages of the present method are that no FFA isolation procedures are required, the reactions proceed under mild temperature conditions, and FFA and eFA can be analyzed simultaneously by GC. 相似文献
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Yinqi Wu Dr. Caroline E. Paul Prof. Frank Hollmann 《Chembiochem : a European journal of chemical biology》2021,22(14):2420-2423
The fatty acid photodecarboxylase from Chlorella variabilis NC64 A (CvFAP) catalyses the light-dependent decarboxylation of fatty acids. Photoinactivation of CvFAP still represents one of the major limitations of this interesting enzyme en route to practical application. In this study we demonstrate that the photostability of CvFAP can easily be improved by the administration of medium-chain length carboxylic acids such as caprylic acid indicating that the best way of maintaining CvFAP stability is ‘to keep the enzyme busy’. 相似文献