藻类对微量元素的生物富集及其机理探讨

介绍了藻类生物富集微量元素的特点和研究现状,探讨了藻类生物富集的作用机理。藻类对有益微量元素的富集作用大于毒性元素;藻类生物富集微量元素的作用机理主要为生物吸附和主动运输,并以主动运输途径富集的微量元素具有较高的生物活性。     

Physico‐chemical Characterization of Floridean Starch of Red Algae

The current work reports on isolation and physico‐chemical characterization of floridean starch from three species of agarophytic macro red algae. As determined by ¹H‐NMR spectroscopy, the average chain length and degree of branching frequency of this starch were 18 and 4.8, respectively. According to its amylopectin chain length distribution obtained by Dionex analysis, the crystalline polymorph of floridean starch from the red alga Gracilariopsis lemaneiformis was deduced to be C‐type and this was further supported from its X‐ray crystallographic pattern. Enzymatic analysis of its glucose 6‐phosphate content showed that floridean starch had a low level of covalently linked phosphate (1 nmol per milligram starch) and this was further confirmed by ³¹P‐NMR. The absorbance peak of floridean starch with iodine occurred at 527—530 nm and the blue value was low (0.1), indicating the absence of amylose, which was confirmed by differential scanning calorimetry (DSC). Floridean starch exhibited low gelatinization temperature, low viscosity, high clarity and little or no retrogradation upon repetitive freeze‐thaw cycles, as studied by DSC and rapid viscosity analysis (RVA). These results are discussed in light of the functional properties and the structure of floridean starch.     

利用海带粉回收铜电解废液中铜的试验研究

研究海带粉对铜电解废液中Cu^2 的吸附行为实验表明：海带粉的最佳投加量为1．5g／l;在摇床转速为120r／min,温度为25℃,吸附时间60min,最佳pH为4～7条件下,对[Cu^2 ]=80mg／L的模拟废电解液进行吸附,最大吸附率为97．8％．实际废水的处理结果表明：对废电解液中Cu^2 吸附率达到99．5％,可达标排放．     

蓝藻为载体的阿维菌素抗紫外缓释剂的制备及其性能

以滇池蓝藻为载体,利用其抗紫外特性,用卡波姆树脂包裹蓝藻-阿维菌素(Avermectin, Av)粉,制成阿维菌素抗紫外缓释剂,利用FT-IR, SEM和HPLC等对蓝藻和缓释剂进行表征,研究其吸附与释放行为. 结果表明,Av在异丙醇中的饱和吸附量为160.81 mg/g,包裹10%卡波姆树脂的抗紫外缓释剂具有很好的缓释功能,在乙醇/水(4:1, j)中释放20 d,累计释放率为51.8%,释放机制是Fick扩散和骨架溶蚀的双重机制. 经4 h紫外光照射,含蓝藻的制剂中Av残留量为61%,不含蓝藻的制剂中Av残留量为39%.     

Epibiotic microorganisms on copepods and other marine crustaceans

Although the occurrence of microbial (algal, protozoan, bacterial, and fungal) epibionts on marine crustaceans and other invertebrates has been documented repeatedly, the ecological context and significance of these relationships generally are not well understood. Recently, several studies have examined the population and community ecology of algal and protozoan epibionts on freshwater crustaceans. Even so, the study of microbial epibionts in aquatic environments is still in its infancy. In this review, we summarize associations of microalgae, protozoans, and bacteria with marine crustaceans, especially copepods. We note differences and commonalities across epibiont taxa, consider host-epibiont cycling of nutrients, generate hypotheses relevant to the ecology of the host and the epibiont, and suggest future research opportunities. Microsc. Res. Tech. 37:116–135, 1997. © 1997 Wiley-Liss, Inc.     

氯离子浓度与电流密度对电解抑制铜绿微囊藻生长的影响

通过分析电解前后铜绿微囊藻液的光密度与叶绿素荧光动力学参数变化,探究了氯离子(Cl^-)浓度及电流密度对微电流电解抑制铜绿微囊藻生长的影响。结果表明:微电流电解产生的活性氯在抑藻过程中起了重要作用,对初始细胞密度5×10⁵个/mL、体积100 mL的铜绿微囊藻液而言,当藻液中初始Cl^-浓度为18 mg/L时,电解后藻细胞的生长受到了完全抑制;而对于无氯藻液,电解后藻细胞的生长未受明显影响。当电流密度为10 mA/cm²、电解时间为15 min,而藻液中的初始Cl^-浓度在0～18 mg/L范围内时,电解抑藻效率会随着Cl^-浓度的升高而逐步提高;并且当Cl^-浓度≥12 mg/L时,电解后藻细胞彻底死亡,无法再恢复活性。当电解时间为15 min、藻液中初始Cl^-浓度为18 mg/L,电流密度在0～20 mA/cm²范围内时,随着电流密度的增加电解抑藻效率也会提高。成果为深入研究微电流电解的持续抑藻机理提供了基础。     

冷却水中藻类去除方法的研究进展

藻类污染作为水体污染的一部分,已引起人们的广泛关注。作者对物理法、化学法和生物法去除冷却水中的藻类的国内外现状进行了概述。综述了光磁协同、电化学等物理除藻方法,铜电解、臭氧氧化、化学药剂复配等化学除藻方法,以及利用水网藻和改性海带的生物除藻方法。并对各种方法的除藻机理及应用效果进行了简述。在总结国内外研究的基础上,对未来发展前景进行了评价和展望。     

对白洋淀水体BOD5测试方法的探讨

白洋淀水体中的水生藻类植物严重干扰测定五日生化需氧量,从反应原理上分析了产生干扰的原因,提出去除干扰的方法,并通过对比试验对方法进行了肯定。     

海洋赤潮生物检测技术研究进展

赤潮是我国近海主要的多发性海洋生态灾害,加强赤潮生物检测技术研究,对于赤潮预报与治理工作具有重要的现实意义。本文综述了海洋水色遥感监测技术、赤潮生物光学检测技术及赤潮生物生物学分析技术的研究现状及其发展趋势。     

Repeated production of hydrogen by sulfate re-addition in sulfur deprived culture of Chlamydomonas reinhardtii

Biological hydrogen production by the green alga, Chlamydomonas reinhardtii can be induced in conditions of sulfur deprivation. In this study, we investigated the repeated and enhanced hydrogen production afforded by the re-addition of sulfate with monitoring of pH and concentration of chlorophyll and sulfate. Without adjustment of the pH, the optimal concentration of re-added sulfate was 30 μM for the hydrogen production. By the re-addition of 30 μM of sulfate and the adjustment of the pH during 4 cycles of repeated production, we obtained the maximum amount of 789 ml H₂ l⁻¹ culture, which is 3.4 times higher than that of one batch production without adjustment of pH, 236 ml H₂ l⁻¹ culture. This means that the enhancement of the hydrogen production can be achieved by the careful control of the sulfate re-addition and pH adjustment in the sulfur deprived culture.