光纤荧光海藻浓度测量仪的研究

本文提出了一种检测海水中藻类浓度的新方法 ,在利用原有浓度检测原理的基础上 ,应用光纤和荧光技术 ,采用脉冲氙灯作为激发光源 ,并配合有效的微弱信号检测技术以实现藻类浓度的在线测量 .该系统具有结构简单、水下探头无源以及高精度、高灵敏度等特点 .实验证明 ,该系统用于海藻浓度的检测是可行的 ,也可应用此方法检测海水中其它物质的浓度 .

马铃薯蛋白高效提取分离技术优化

以市售马铃薯块茎为材料,用海藻酸钠法和酸碱沉淀法提取马铃薯蛋白质,采用Bradford法测定蛋白质浓度,同时采用SDS-聚丙烯酰胺凝胶电泳技术(SDS-PAGE)对马铃薯蛋白种类进行分析。结果表明:采用不同提取方法所得蛋白质含量差异显著。以海藻酸钠提取马铃薯蛋白质,随着海藻酸钠百分含量增加,蛋白含量先增加后减少,且以海藻酸钠浓度为0.15%,pH为4.2时蛋白含量最高。以酸碱沉淀法提取马铃薯蛋白,随着pH值增大,蛋白含量先增加后减少,且以碱沉淀pH=8.0、酸提取pH=4.6时蛋白含量最高。电泳结果分析表明:海藻酸钠法和酸碱沉淀法提取的蛋白种类无显著差异,为深入研究不同马铃薯中蛋白的种类差异奠定基础。

Optical Fiber Fluorometer for Algae Detection and Mapping

A simple instrument for the real-time measurement of algae concentration and mapping is described. The instrument uses a pulsed short arc xenon flashlamp as the excited light sources. Both the exciting light and the fluorescence from algae chlorophyll are transmitted along a fiber bundle. The measurement sensitivity is analyzed and the experiment result is given. The instrument is practical to in-situ measurement at sea.

Production of dimethylsulfide and acrylic acid from dimethylsulfoniopropionate during growth of three marine microalgae

We measured the concentrations of dimethylsulfide(DMS),acrylic acid(AA),and dimethylsulfoniopropionate(DMSP) during growth of three microalgae:Prorocentrum micans,Gephyrocapsa oceanica,and Platymonas subcordiformis.The DMSP,AA,and DMS concentrations in culture media varied significantly among algal growth stages,with the highest concentrations in the late stationary growth stage or the senescent stage.In the stationary growth stage,the average DMSP concentration per cell in P.micans(0.066 5 pmol/cell) was 1.3 times that in G.oceanica(0.049 5 pmol/cell) and 20.2 times that in P.subcordiformis(0.003 29 pmol/cell).The average concentrations of AA were0.044 6,0.026 9,and 0.003 05 pmol/cell in P.micans,G.oceanica,and P.subcordiformis,respectively,higher than the concentrations of DMS(0.272,0.497,and 0.086 2 fmol/cell,respectively).There were significant positive correlations between cell density and AA,DMSP,and DMS concentrations.The ratios of DMS/AA and AA/(DMSP+AA) in the three algae differed significantly over the growth cycle.In all three microalgae,the DMS/AA ratios were less than 25%during the growth period,suggesting that the enzymatic cleavage pathway,which generates DMS,was not the main DMSP degradation pathway.The changes in the DMS/AA ratio indicated that there was a higher rate of enzymatic breakdown of DMSP in the early growth period and a lower rate during senescence.In all three microalgae,the AA/(DMSP+AA) ratio(degradation ratio of DMSP) decreased during the exponential growth phase,and then increased.The variations in these ratios can approximately indicate the cleavage mechanism of DMSP at different stages of algal growth.

Effect of Fe^(3+) on the growth and lipid content of Isochrysis galbana

Inducing lipid accumulation in microalgae cells without suppressing cell growth is vital to the economical production ofbiodiesel from microalgae. In two experiments, we demonstrate that the eel1 concentration and lipid content of marine microalgae Isochrysis galbana depend upon the iron concentration in the growth media. In Experiment I, adding chelated FeC13 to the medium at the late exponential growth phase prolonged this phase and increased the lipid content in I. galbana cells. The final cell density and lipid content of I. galbana supplemented with chelated FeC13 was approximately 2 and 1.65 times higher than that of non-supplemented cultures, respectively. In Experiment II, I. galbana cells in the late exponential phase were collected and re-inoculated into new media containing Fe3＋ at various concentrations. The final cell concentration and lipid content were maximized at the highest iron concentration （38% biomass by dry weight at 1.2×10^-5 mol/L Fe3＋）. In this study, intracellular neutral lipid storage was evaluated by fluorescent spectrophotometry using fluorochrome Nile red, and the measurement conditions were optimized.

Anti-proliferative activity of phlorotannin extracts from brown algae Laminaria japonica Aresch

In this study, we evaluated the anti-proliferative activity of phlorotannins derived from brown algae Laminariajaponica Aresch extracts on the human hepatocellular carcinoma cell （BEL-7402） and on routine leukemic cells （P388） by MTT assay. Cells were incubated with 100 μg/mL of the phlorotannin extract （PE） for 48 h. The inhibitory rate of PE on BEL-7402 and P388 cells was 30.20±1.16% and 43.44±1.86%, respectively, and the half-inhibitory concentration of PE （IC50） on P388 and BEL-7402 cells was 120 μg/mL and 〉200 μg/mL, respectively. Microscopic observation shows that the morphologic features of tumor cells treated with PE and 5-fluorouracil are markedly different from the normal control group. The inhibitory rate of fraction A2 isolated from PE by sephadex LH-20 for BEL-7402 and P388 cells at the sample concentration of 70.42 μg/mL was 61.96±7.02% and 40.47±8.70%, respectively. The apoptosis peak for fraction A2 was the most profound of all fractions used in the flow cytometry assay. The results indicate that the anti-proliferative of this algal extract is associated with the total phlorotannin content.

用胡萝卜加工可食性蔬菜彩色纸

食品大量应用塑料来包装,由于塑料极难自然降解,塑料垃圾很难处理,因此一些发达国家已部分限制塑料包装的使用。开发应用可食性包装纸是减少垃圾、保护环境的有效途径之一。本文探讨的是以胡萝卜为基料,添加适当的增稠剂、增塑剂、抗水剂,利用胡萝卜天然色泽,制成价廉物美...

“酵母细胞固定化”实验的改进与教学优化

探索了海藻酸钠质量浓度及CaCl_(2)溶液浓度对固定化酵母细胞机械强度和发酵效果的影响,改进了制作凝胶珠的工具与发酵装置,缩短了实验所需时间,有效地优化了酵母细胞固定化实验教学。