中文摘要：

在不同浓度亚硒酸钠（Na2SeO3）条件下培养海洋球石藻,分析其生长和富集硒情况,并采用（NH4）2SO4分级盐析、DEAE-Sepharose离子交换柱层析和SephacrylS-200凝胶过滤层析方法,对球石藻硒蛋白进行了初步分离纯化。结果表明,在本实验条件下,不添加外源硒的f/2培养基本底硒浓度（约3.2nmol/L）为海洋球石藻最佳生长和富硒的硒浓度,其细胞内硒含量可达到6475？g/g干重。离子交换和凝胶层析分离的含硒蛋白结合的最高硒含量分别达到392.3ng/mg和663.5ng/mg蛋白。SDS-PAGE纯度鉴定显示,在分子量分别约为41.3kDa和30.1kDa处各有单一电泳条带。结果提示,海洋球石藻能在环境硒浓度极低的条件下大量吸收硒并将大部分无机硒转化为硒蛋白。富硒能力较强的海洋球石藻有望作为一种新的有机硒资源,对开发含硒安全性食品具有很大的应用潜力。

英文摘要：

We investigate the growth and bioconcentration of selenium in a Coccolithophorid, Emiliania huxleyi （Eh-BOF92） after culturing in different selenium （Na2SeO3） concentration. Highly pure selenoproteins are isolated and purified from E. huxleyi using ammonium sulfate fractionation, followed by DEAE-Sepharose anion-exchange chromatography and gel filtration column chromatography （Sephacryl S-200）. The results show that without extra addition of Se （background concentration of Se in sea water： ≈3.2nmol/L） in the substrate is the optimal concentration of Se for E. huxleyi in facilitating its growth. In Se-enriched E. huxleyi, most selenium is in organic form and incorporates into proteins probably in the form of selenocysteine, and intracellular Se content can reach up to 6475？g/g dry weight. Two selenopro teins with the molecular mass of 41.3kDa and 30.1kDa are detected by SDS-PAGE. Se contents of the two purified selenoproteins are 392.3ng/mg and 663.5ng/mg of proteins, respectively. These results indicate that E. huxleyi has high capacity for seleninm bioaccumulation and a potential natural resource to be developed into a new type of selenium-rich product.