【作者】 唐海溶；

【导师】 王艳；

【作者基本信息】 暨南大学 ， 环境科学， 2006， 硕士

【副题名】SOD和CAT活性的研究

【摘要】 本文以我国南海海域分离的赤潮原因种——球形棕囊藻（Phaeocystis globosa）为材料，研究了球形棕囊藻在不同营养条件下的生理状况及在逆境下两种重要的抗氧化酶（SOD和CAT）的活性变化。 结果表明：不同硝酸盐浓度对球形棕囊藻生长及硝酸还原酶活性的影响不同。当培养基中缺乏硝酸盐，藻细胞内硝酸还原酶的活性保持在非常低的水平，不能形成正常的生长曲线；在培养基中添加不同浓度的硝酸盐，对球形棕囊藻细胞硝酸还原酶的活性和藻细胞的生长有极显著的影响，尤其当培养基中硝酸盐浓度为3.62μmol·L^-1时，藻细胞的硝酸还原酶活性和比生长速率达到最大，这说明了含有较高硝酸盐的富营养化海域有利于球形棕囊藻细胞的持续生长。 球形棕囊藻在缺磷和大分子DOP（卵磷脂）作为磷源的情况下，碱性磷酸酶活性迅速提高，在第9天达到了最大值，其活性分别为19.11U和18.28U，显然在缺磷胁迫下和大分子DOP的利用过程中碱性磷酸酶起着重要作用。DIP（磷酸二氢钾）和小分子DOP（β-甘油磷酸钠）都容易直接被球形棕囊藻吸收利用，碱性磷酸酶活性变化不明显。 球形棕囊藻在逆境胁迫下超氧化歧化酶（SOD）以及过氧化氢酶（CAT）的变化表明：磷是影响球形棕囊藻生长的一个极其显著的因子，浓度过高或过低，都会导致SOD以及CAT水平大大的提高。氮和盐度对球形棕囊藻生长的影响分别次于磷素对其影响，在氮素和盐度的高浓度或低浓度胁迫下，SOD活性会有所上升，然而CAT活性反而降低，说明了球形棕囊藻SOD与CAT活性与环境胁迫有关。更多还原

【Abstract】 HAB （harmful algae bloom） causative species—Phaeocystis globosa, which was isolated from South China Sea was grown in modified F/2-medium with different conditions. Nutrient physiology and two important anti-oxidant enzyme（SOD and CAT） activity in P. globosa were investigated in the present paper.When P. globosa grown in the medium without nitrate, NR activity was maintained at very low level, algal cell growth was inhibited and no growth curve was observed. Cell density and NR activity in P. globosa were significantly different when growing at different nitrate concentrations. The optimum nitrate concentration for algal cell growth and NR activity was 3.62 μmol·L^-1. The present results imply that eutrophic sea water with high nitrate concentration is suitable for the growth of P. globosa, and has great potential of developing into red tide.When phosphorus deficiency and large molecular DOP （Lecithin） used in this experiment, alkaline phosphatase activity in P.globosa cells increased to 19.11U and 18.28U respectively, and both of them peaked at day 9. Results showed alkaline phosphatase played an important role in phosphorus deficiency stress and the utilization of large molecular DOP. DIP （KH₂PO₄） and small molecular DOP （Natrium-β-glycerophosphat） can be easily utilized by P.globosa, whereas alkaline phosphatase activity did not changed significantly.A study of adverse stress on superoxide dismutase（SOD） and catalase（CAT） activity of P.globosa were investigated. Results showed that phosphorus was the most significant factor limiting the growth of P. globosa. The activity of SOD and CAT significantly improved under phosphorus stress. Nitrate and salinity also affected the growth of the algae. The activity of SOD slightly increased under stress of nitrate and salinity, while the activity of CAT slightly decreased.更多还原