摘 要:钴是一种重金属元素,是生物体内文生素B12的组成部分。然而,在冶金、颜料、陶瓷釉料等工业生产过程中,大量的钴被排放至水体中。当钴离子的浓度超过一定的范围时,便会对生物造成相应的胁迫伤害。水体中的各种藻类、原生生物是包括钴在内的各种重金属胁迫首当其冲的受害者,而且重金属会随着食物链而逐级富集,对各级消费者尤其是人类的健康造成巨大的威胁。在水污染愈来愈严重的今天,实时监测水体中各种重金属等污染物的浓度,研究典型水体生物对重金属胁迫的生理响应及分子机制,通过物理化学或生物吸附的方法减少重金属含量及其毒性效应,是亟待解决的问题。集胞藻6803是一种淡水生单细胞蓝藻,因其个体微小、对各种胁迫响应迅速、环境适应性强、便于进行遗传操作和生理指标测定等特点,是研究胁迫响应的理想材料。本研究以集胞藻6803为材料,研究了不同浓度的Co2+处理对藻细胞生长的影响。结果表明:Co2+处理对集胞藻6803的生长及光合色素含量、蛋白质图谱等都有显著影响。当Co2+浓度为5µM时,集胞藻6803的生长明显受到抑制,同时藻细胞的叶绿素含量、类胡萝卜素含量和蛋白含量等均显著降低;当Co2+浓度为30µM时,集胞藻6803的生长完全被抑制,藻细胞基本停止生长甚至死亡。34525 毕业论文关键词:钴;集胞藻6803;生长;光合色素;蛋白质
Effects of cobalt on the growth of Synechocystis sp. PCC6803
Abstract: Cobalt is one of the heavy metal elements; it is an important component of vitamin B12 in vivo. However, in the process of industrial production such as metallurgy, dyestuff, ceramic glaze and so on, cobalt was largely discharged into water body, causing corresponding injure to variety of life in case its concentration is beyond a certain range. Algae and quite a lot of protista underwater is the first victim of various heavy metals including cobalt. Besides, heavy metal could be accumulated and enriched in the food chain, giving rise to great threat to consumers at all levels particular human health. Currently, water pollution is increasingly severe, and these subjects are urgently to be solved, for instance, monitoring the situation of heavy metal pollution in the water, study on the effects and molecular mechanism of heavy metal on the growth of typical aquatic organisms, reducing the content and alleviating the toxic effects of heavy metals by means of physicochemical and biological adsorption. Synechocystis sp. PCC6803 is one of the unicellular limnetic cyanobacteria which possess numerous advantages: small inpiduals, quick response to various stresses, well-adapted to a variety of environments and convenient for genetic manipulation, and these characteristics make Synechocystis one of the model organisms in study of stress responses. In the present research, effect of different concentration of cobalt on the growth of Synechocystis sp. PCC6803 was studied. The results showed that cobalt treatment impacts the growth, photosynthetic pigments contents as well as the protein profile of Synechocystis cells significantly. Specifically, when cells were cultured in the medium containing 5µM Co2+, the growth was retarded and the contents of chlorophyll, carotenoid and protein were reduced almost by half. While, 30µM Co2+ almost totally inhibited cell growth and even to die.
Keywords: Cobalt; Synechocystis sp. PCC6803; Growth; Photosynthetic pigments; Protein
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