从我国南海北部大洋陆架外海域中取样分离培养的1株微微型浮游植物(SCSIO-8), 以它为材料, 对其生长特征、形态结构、生理生化特性和分类鉴定等进行了研究。研究结果表明, SCSIO-8为游离单细胞, 细胞大小为  (2.08±0.28µm)×(1.78±0.09)µm, 无鞭毛, 无蛋白核, 以似亲孢子方式繁殖, 形成2、4个子细胞; 扫描电镜观察, SCSIO-8具有1个细胞核、1个线粒体和1个叶绿体, 形成大量淀粉粒; SCSIO-8适应生长的盐度范围至少为0‰―38‰, 并可快速适应海淡水之间的转换; HPLC分析显示SCSIO-8细胞含有叶绿素a、b以及顺/反式紫黄质、?-胡萝卜素和叶黄素等类胡萝卜素组分; 经18S rDNA测序和对比分析, 结合其细胞形态结构、生理生化特性, 初步鉴定为Picochlorum sp. SCSIO-8。

In this study, strain SCSIO-8, an isolated picophytoplankton was obtained from the continental shelf of the northern South China Sea. Studies were carried out on its growth, morphological structure, physiological and biochemical characteris-tics and taxonomic identification. The results indicate that SCSIO-8 was a free unicellular alga without flagellate, (2.08±0.28)×(1.78±0.09)µm in size, and no pyrenoid, 1 chloroplast, 1 mitochondria, 1 nucleus, and many starch granules were observed in its cell. It was revealed that SCSIO-8 reproduced through autosporation. Results also indicate that SCSIO-8 was able to grow in a wide range of salinity from 0 to 38‰ at least, and adapted rapidly to the mutual switch between seawater and freshwater. HPLC chromatogram analysis showed that the main photosynthetic pigments of SCSIO-8 were chlorophyll a, chlorophyll b, and several carotenoids including cis- and trans-Violaxanthin, Lutein, β-carotene, etc.18S rDNA region of SCSIO-8 genome DNA was sequenced and blasted in GenBank. The picophytoplankton strain could be identified as Pi-cochlorum sp. SCSIO-8 through integrated analysis of its morphological, physiological, biochemical, and molecular charac-teristics.

广东省科技计划项目(2009B080701093); 广东省海洋与渔业局科技专项项目(A2008009-08)

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