六价铬对集胞藻6803生长的影响
毕业论文关键词：集胞藻6803；Cr6+；生长；光合色素；蛋白图谱
Effects of hexavalent chromium on the growth of Synechocystis sp. PCC6803
Abstract: Chromium is one of the heavy metal elements which can exists in three forms: chrome metal, trivalent chromium and hexavalent chromium, and all of them are toxic. There are only the latter two forms of chromium in natural environment, while hexavalent chromium possesses the maximum toxicity. Due to the strong corrosion resistance, chromium was widely applied in electroplate, metalworking, the tanning industry, with massive emission of exhaust gas and waste water into environment. While, hexavalent chromium is an inhaled toxic substance, skin exposure and mucosal contact might cause allergy, gene mutation, genetic defect, and may cause cancer. It could also be enriched when passing through the food chain, resulting in great harm to environment and living organisms. Nowadays, the conditions of air and water pollution are growing worse, 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 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，available genomics 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 hexavalent chromium on the growth of Synechocystis sp. PCC6803 was studied. The results showed that hexavalent chromium treatment differently impacts the growth, photosynthetic pigments contents as well as the protein profiles of Synechocystis cells. Specifically, when cells were cultured in the medium containing 10µM Cr6+, the growth curve was comparative to the control, although the contents of chlorophyll and carotenoid were remarkably reduced. While, 30µM Cr6+ treatment had a strong impact on growth, cell culture showed abnormal yellow color, and the content of photosynthetic pigments declined seriously. Nevertheless, neither of the treatment affects the protein profiles of total proteins in cells.