钝顶螺旋藻干粉叶绿素a提取方法探讨

采用正交实验对超声法提取钝顶螺旋藻叶绿素a技术进行优化,研究固液比、超声功率、超声时间对叶绿素a提取率的影响。结果表明,优化条件为:固液比1∶500(g/m L),超声功率80%,超声时间20 min。在此条件下,钝顶螺旋藻叶绿素a提取率达1.545%。     

从钝顶螺旋藻提取色素的初步探讨

本文初步研究了从螺旋藻中提取藻蓝素、叶绿素a和β-胡萝卜素的方法,并将叶绿素a制成它的铜钠盐。     

响应面法优化螺旋藻中叶绿素的超声提取工艺

Chlorophylls were extracted by using ultrasonic from Spirulina platensis. Single factor examination and response surface analysis experiments were adopted to investigate the effects of extraction time, extraction solvent, solvent concentration, ratio of liquid to solid and extraction grade. The results showed that the optimal process parameters for this method were: extraction time of 56.5 min, ethanol concentration of 48.3% (vol) of ethanol/acetone solvent, and ratio of liquid to solid of 7. 9 ml·g^-1. The optimized chlorophylls extraction yield was 1.28%. The comparison experimental results indicated that the yield of chlorophylls by ultrasonic extraction was higher than that obtained from conventional solvent extraction.     

钝顶螺旋藻中γ-亚麻酸甲酯的提取研究

用１∶２∶０８（Ｖ／Ｖ）的氯仿 甲醇 水溶剂系统提取螺旋藻中总类脂,总类脂在硅胶柱上经氯仿、丙酮、甲醇依次洗脱,分离得到中性脂、总脂肪酸半乳糖脂、磷脂。总脂肪酸半乳糖脂与５∶９５（Ｖ／Ｖ）的氯乙酰 甲醇作用转变为总脂肪酸甲酯,再通过多次与尿素形成复合物,可从总脂肪酸甲酯中分离、纯化出 亚麻酸甲酯,其纯度达到了９６５％。     

地表水中叶绿素a的提取方法探讨

环境检测水中叶绿素a的标准方法为丙酮为萃取溶剂的分光光度法,存在检测结果误差较大,重复测定精密度较差,同时在研磨过程中,分析者暴露在高浓度的丙酮环境中,有损身体健康,加之研磨和转移过程致使叶绿素a损失,使得检测结果偏低。改进后方法以热乙醇作溶剂,滤膜置于低温冰箱冷冻后,再以匀浆器和超声波仪辅助,热乙醇多次提取,提高了叶绿素a的提取效率。研究建立的方法在水中叶绿素a的快速和应急测定方面值得推广使用。     

钝顶螺旋藻中藻蓝蛋白提取纯化新工艺

用０３ｍｍｏｌ／Ｌ的十二烷基苯磺酸钠提取钝顶螺旋藻中的藻蓝蛋白,提取率达到了９８％。再在硅藻土５４５柱上分级洗脱,进一步经ＤＥＡＥ—纤维素柱纯化,其纯度达到了４１（指可见区最大吸收与２８０ｎｍ处之比）,最大吸收峰在６１９ｎｍ,室温荧光发射峰在６４３ｎｍ。     

测定叶绿素a方法探讨

叶绿素测定是生物监测水质及评价中估算藻类生物量的重要指标.对测定生产力中叶绿素a的方法进行了探讨与改进,并进行了方法的验证.实验证明,本方法具有简单、快速、准确等优点.     

钝顶螺旋藻中藻胆蛋白体的分离纯化

用 0 .3m mol· L- 1的十二烷基苯磺酸钠提取钝顶螺旋藻中的藻蓝蛋白和别藻蓝蛋白 ,再在硅藻土5 4 5柱上分级洗脱 ,进一步经 DEAE-纤维素柱纯化 ,藻蓝蛋白纯度达到了 4 .1(指可见区最大吸收与 2 80 nm处之比 ) ,最大吸收峰在 6 19nm,室温荧光发射峰在 6 4 3nm。别藻蓝蛋白纯度达到了 4 .7(指可见区最大吸收与 2 80 nm处之比 ) ,最大吸收峰在 6 5 2 nm,室温荧光发射峰在 6 6 7nm     

钝顶螺旋藻超氧化物歧化酶的原核表达及纯化

目的原核表达并纯化钝顶螺旋藻超氧化物歧化酶(superoxide dismutase,SOD)。方法利用PCR技术扩增钝顶螺旋藻sod基因,克隆入原核表达载体pGEX-4T-1,构建重组表达质粒pGEX-4T-sod,转化大肠埃希菌BL21(DE3)pLysS,IPTG诱导表达。表达的重组融合蛋白SOD-GST利用蛋白纯化树脂Glutathione SepharoseTM4 Fast Flow纯化后,采用改进的邻苯三酚自氧化法测定重组SOD的活性。结果重组表达质粒pGEX-4T-sod经双酶切和测序证实构建正确;表达的融合蛋白SOD-GST的相对分子质量约为49 000,表达量占菌体总蛋白的30.2%,在重组菌裂解上清和沉淀中均有融合蛋白的表达;纯化的融合蛋白纯度为82.4%,浓度为2.8 mg/ml,从可溶性表达产物中纯化的酶的比活性为1 440 U/mg。结论在大肠埃希菌中成功表达并纯化了具有生物学活性的钝顶螺旋藻SOD,为其产业化生产奠定了基础。     

螺旋藻中类脂提取方法的研究

介绍了螺旋藻中类脂的两种提取方法即甲醇一氯仿溶剂冷提法和丙酮－水系统热提法,并且就各个因素对提取效果的影响进行了详细研究。     

铵盐对螺旋藻生长的影响

研究了不同浓度的硫酸铵[(NH4)2SO4]和乙酸铵(CH3COONH4)对螺旋藻生长的影响. 实验结果表明,从实验设计的浓度梯度来看,螺旋藻能耐受的硫酸铵和乙酸铵浓度分别为0.5和0.6 g/L,相应的铵氮含量分别为212和109 mg/L. 培养结束时硫酸铵和乙酸铵的去除率分别为85.38%和99.7%. 添加的乙酸铵几乎全部被螺旋藻利用,并且蛋白质含量明显提高.     

Influence of pre-soaking conditions on ultrasonic extraction of Spirulina platensis proteins and its recovery using aqueous biphasic system

Ultrasonic aqueous extraction of proteins from dry Spirulina platensis at acidic (ACSU), alkali (ALSU), and neutral (NSU) conditions and its recovery using aqueous biphasic system (ABS) was studied. S. platensis was soaked in the solvent for 12 h prior to extraction. Neutral condition showed a higher protein release of 18.6 mg/ml at optimum conditions (solid–liquid ratio 1:20, 80% ultrasound amplitude, 100% ultrasound duty cycle, and 4ºC). The Box–Behnken design (BBD) suggested optimum conditions for ABS (PEG 6000, pH 8, and 5% NaCl) and gave 84.1% recovery. Although microscopic observations indicated structural changes, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier-transform infrared spectroscopy (FTIR) analyses confirmed that the proteins are intact.     

超声波辅助混合溶剂提取蚕沙中叶绿素的工艺研究

以石油醚-丙酮混合溶剂为提取剂,采用超声波辅助法提取蚕沙中叶绿素,以叶绿素提取率为目标,对超声时间、超声温度、超声功率、固液比、助剂(丙酮)含量和提取次数进行优选研究。结果表明,最佳提取工艺为提取次数4次,助剂(丙酮)含量20%,固液比1∶4(g/mL),超声时间50 min,超声功率90 W,超声温度45℃。在此优化条件下,蚕沙中叶绿素提取率为90.6%。     

Electrochemical behaviour of iron and copper in a culture solution for Spirulina platensis

Cyclic voltammograms of iron and copper electrodes were run in sodium hydroxide, carbonate–bicarbonate buffer and culture media for Spirulina platensis at 30°C. Potentiostatic steady state polarisation curves for both electrode surfaces in these electrolytes were performed in the presence and the absence of S. platensis at fixed temperature. Corrosion potential and corrosion current density values of iron and copper were obtained graphically from these curves. In all cases, the largest corrosion current density corresponded to the maximum biogenerated-oxygen concentrations, that is, illuminated culture media containing S. platensis. Corrosion potentials of iron electrodes shifted to positive values for increasing corrosion rates, whereas constant corrosion potentials were obtained for copper electrodes independently of the electrolyte.     

苦瓜叶绿素的提取和稳定性的研究

对苦瓜中叶绿素的提取方法及温度、pH、光照、氧化剂、还原剂、金属离子等对叶绿素稳定性的影响进行了研究.结果表明:选取丙酮:无水乙醇=1:1的混合溶剂为提取剂,浸提时间3h,液料比12:1,温度50℃作为苦瓜叶绿素的优化提取条件.该叶绿素具有较好的耐还原性,在pH=6～8的范围内稳定性较好,对常用的食品添加剂性质稳定,但热稳定性较差,只能在95℃范围内稳定,且在光照条件下会发生光降解现象.     

Supercritical CO2 Extraction of Chlorophyll a from Spirulina platensis with a Static Modifier

Supercritical CO₂ extraction with a static modifier was applied to extract chlorophyll a from Spirulina platensis. The effects of the process were investigated by single‐factor and response surface analysis experiments. The optimal process parameters for supercritical CO₂ extraction were determined to be: ethanol/water as the modifier, 40 vol.‐% water content in the modifier, 21.2 mL modifier volume, 1 h static soaking time, 2 h dynamic extraction time, 48.7 MPa extraction pressure, 326.4 K extraction temperature, and 10 g min^–1 CO₂ flow rate. The optimized chlorophyll a extraction yield was 6.84 mg g^–1. A comparison of the experimental results suggested that the yield of chlorophyll a by supercritical CO₂ extraction with modifier was higher than that obtained by conventional solvent extraction.     

The occurrence and biosynthesis of gamma-linolenic acid in a blue-green alga,Spirulina platensis

The acyl-lipid and fatty acid composition of six blue-green algae, namely,Spirulina platensis, Myxosarcina chroococcoides, Chlorogloea fritschii, Anabaena cylindrica, Anabaena flos-aquae, and Mastigocladus laminosus is reported. All contain major proportions of mono-and digalactosyl diglyceride, sulfoquinovosyl diglyceride, and phosphatidyl glycerol, but none possess lecithin, phophatidyl ethanolamine, or phosphatidyl inositol. Trans-3-hexadecenoic acid was absent from all extracts. The analyses provide further evidence that there is no general chemical or physical requirement for any specific fatty acid in photosynthesis. S. platensis is unique among photoautotrophic organisms so far studied, containing major quantities of γ-linolenic acid (6,9,12-octadecatrienoic acid). This acid is synthesized by the alga by direct desaturation of linoleic acid and is primarily located in the mono- and digalactosyl diglyceride fractions. The possible phylogenetic relationship betweenS. platensis and other plant forms is discussed.