海带对多环芳烃的吸收及代谢研究

IOCAS-IR > 海洋环流与波动重点实验室

	海带对多环芳烃的吸收及代谢研究
其他题名	Uptake and degradation of polycyclic aromatic hydrocarbons by brown seaweed, Laminaria joapnica
	赵红梅
学位类型	博士
	2007-04-25
学位授予单位	中国科学院海洋研究所
学位授予地点	海洋研究所
关键词	海带多环芳烃植物修复降解抗氧化酶
摘要	多环芳烃是环境中一种普遍存在的有机污染物。目前国内水体已受到了多环芳烃的严重污染，因而研究开发治理有机污染物的有效方法对于沿海生态系统的恢复具有重要意义。但现在对水体尤其是海洋环境中的多环芳烃植物修复仍知之甚少。本课题在实验室中研究了海带对两种多环芳烃（菲和芘）不同浓度下的吸收及降解，并对代谢过程进行了初步探索。海带对多环芳烃的吸收及代谢与多环芳烃的初始浓度及种类有关。多环芳烃浓度较低（<0.2mg/l）时，海带对多环芳烃具有很强的吸收及代谢能力。0.1mg/l多环芳烃中，加入海带后对菲和芘的去除效率分别为：99.88-99.89%和94-96.5%；而不加海带的对照液中菲和芘的去除效率分别为46.9%和44.7%。有约51.34%的菲、45.7%的芘被海带完全去除，证实了海带对多环芳烃的代谢。检测到了海带对芘的代谢产物二氢二醇芘，说明海带对多环芳烃的代谢过程为双加氧酶催化；且有少量二氢二醇芘的配合物生成，但结合物结构尚不确定。高浓度的多环芳烃对海带具有极大危害，强烈抑制了海带生长，破坏了其色素体。海带体内的叶绿素-a及类胡萝卜素含量随时间、多环芳烃浓度而下降；过氧化物酶（POD）及超氧化物歧化酶（SOD）受激后活性升高，能对植物的生长起到一定的保护作用； POD能参与到藻体对多环芳烃的第一步氧化过程。总之，海带能在一定浓度范围内（低于0.2mg/l）吸收、降解多环芳烃，能用来对多环芳烃污染海域进行植物修复。研究也表明高浓度的多环芳烃对海带的生长有强烈抑制作用。将来还应对海带对多环芳烃的具体代谢路径，以及代谢产物的生态影响进行进一步的研究。
其他摘要	Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic contaminants present in environments. In China, with increasing environmental pollution and anthropological disturbances to the coastal environment, developing effective methods for remediating organic pollutants has become an important issue for coastal management and ecosystem restoration. However, little information is available on PAHs uptake and degradation by algae, especially from coastal water. In this study, we investigated the uptake and degradation of two PAHs ( phenanthrene and pyrene), under a range of concentrations from 0.1mg/l to 2.0mg/l, by brown seaweed Laminaria joapnica, and examined the catabolic pathway of PAHs during degradation by seaweed. The uptake and degradation of the two PAHs are concentration and toxicant dependent. In laboratory studies, under a certain range of PAHs concentrations (<0.2mg/l), Laminaria joapnica showed a great capacity to take up and metabolize phenanthrene and pyrene. In laboratory studies, Laminaria joapnica showed a great capacity to take up and metabolize phenanthrene and pyrene. Under the concentration of 0.1mg/l, 99.88-99.89% of phenanthrene and 94-96.5% of pyrene were removed by the seaweed 16 days’ treatment, but the percentage of abiotic loss of these two PAHs in control were 46.9% and 44.7% respectively. Our calculation indicates that at the concentration of 0.1 mg /l, about 51.34% of phenanthrene and 45.7% of pyrene taken up by the seaweed were degraded after two weeks demonstrating that this brown seaweed Laminaria joapnica has great ability to uptake and metabolize PAHs. For the degradation products, dihydro-pyrene-diol was identified as the major metabolite, suggesting that the metabolism of pyrene by Laminaria joapnica was carried out through a dioxygenase pathway. We also found some conjugates of dihydro-pyrene-diol as a potential biodegradation product, but the amount was insufficient to qualify. The addition of PAHs into the culture medium inhibited the growth of Laminaria joapnica, especially at high concentrations. PAHs destroyed the seaweed’s chromatophore and the content of chlorophyll-a and carotenoid in seaweed decreased with time and with the increased concentrations of PAHs. The activities of the two enzymes peroxidase(POD) and superoxide dismutase(SOD) of Laminaria joapnica both increased significantly after exposurer to PAHs as a self defence process of the seaweed against oxyradicals result in PAHs addition. The role of POD was important in the first oxidizing PAHs. In summary, the seaweed Laminaria joapnica has great ability to uptake and metabolize PAHs effectively at certain concentration level, and could be used as a potential model in the phytoremediation at the PAH concentration levels found in contaminated coastal water. Our study also indicate that at high concentrations, the toxicity of PAH to seaweed growth is significant. Further studies will be needed to identify the biodegradation pathways and the ecological effects of the degradation product in coastal waters.
页数	66
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/971
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	赵红梅. 海带对多环芳烃的吸收及代谢研究[D]. 海洋研究所. 中国科学院海洋研究所,2007.

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