中国水产科学Issue(4)：828-836,9.DOI:10.3724/SP.J.1118.2015.140528
黄渤海夏季微藻调查
Investigation of the microalgae inhabiting the summer seawater of Yellow Sea and Bohai Sea
摘要
Abstract
Microalgae are bioresources important for a wide range of applications in aquaculture, environmental treat-ment, medicine, agriculture and industry. For instance, Nannochloropsis sp., Phaeodactylum tricornutum and Skele-tonema costatum have served as natural feed of aquatic animals; Dunaliella salina, Haematococcus pluvialis, and Chlorella vulgaris have been widely used to manufacturing nutraceuticals and cosmetics due to their high content of carotenoids. Although more than 0.2 million species exist on earth, only a very small proportion of microalgae have been exploited. In China, approximately 600 microalgal species have been identified, of them less than 10 species have been cultured on large-scales so far. Isolation and identification of more cultivable microalgal strains from natural envi-ronments is thus foundamental and always appreciated by researching and exploiting communities. Yellow Sea and Bohai Sea are rich in phytoplankton and deemed to be an important microalgal repository. However, the reports on the isolation and cultivation of microalgae inhabiting these sea areas are very scarce. In order to promote the exploitation of microalgal resource in Yellow Sea and Bohai Sea, a surveying cruise was carried out in summer 2011, during which the diversity of net collected microalgae was determined. Moreover, a rich collection of cultivable microalgal strains were successfully isolated from 71 stations. A total of 44 species in 30 genera, 4 phyla, were identified in fixed summer sea-waters. Among them, Bacillariophytas (28 species in 20 genera) accounted for 51.8%; while dinophytas (14 species in 8 genera) accounted for 23.2%. One speceis in phylum Chrysophyta (Dictyocha fibula) and Cyanophyta (Trichodesmium thiebautii) were also isolated and identified. Coscinodiscus sp. and Paralia sulcata which appeared in almost all sta-tions were dominant species. In total, 92 microalgal strains were isolated and purified with diverse methods including capillary catching, streak plating and serial diluting, alone or in combination. Molecular systematic analysis identified the isolated as 19 species including 9 bacillariophytas, 3 phaeophytas, 3 heterokontaes, 2 chlorophytas, 1 dinophytas and 1 haptophyte. The isolated species were mainly small in size, of them 9 in chlorophyta, phaeophyta, heterokonatae and haptophyte were in pico-size, and 10 in bacillariophyta and dinophyta were in nano-size. Among all isolated strains, those in genera Navicula, Phaeodactylum, Skeletonema, Pavlova and Nannochloropsis were expected to be important for EPA production due to their high EPA content; 7 chlorophytas may serve as the candidates for biodiesel production;and 8 Bicosoecales in heterokontae promised for high biomass production therough fermentation and further environ-mental pollution bioremediation. In spite of the abundance of microalgae in Yellow Sea and Bohai Sea, almost all spe-cies we fixed and identified by morphology were difficult to cultivate. Pseudo-nitzschia sp. and Navicula sp. (in nano-size) were the only two species observed in fixed seawater and survived laboratory culture. Although the algae in micro-size, Coscinodiscus sp., Ceratium fusus and Noctiluca scintillans, accounted for a large portion in fixed samples, they were unable to survive laboratory culture. Technical means need further optimization in order to get as many culti-vable microalgae as possible. We found that distribution of cultivable microalgae is wide in seawaters. Bacillariophytas spread the whole area, and centralized in Laizhou Bay; while the harmful Prorocentrum minimum was collected from Yellow River Estuary where was nutriments rich thus facing the risk of red tide. Chlorophytas and haptophyte were mainly collected from north Yellow Sea, a few chlorophytas also collected around Port of Tongxhan. Most phaeophytas were collected from the coasts of Shandong Peninsula and Liaodong Peninsula. Most heterokontaes were collected from north Yellow Sea. In additon, it was the first report that Pseudobodo tremulans inhabits Chinese coastal seawater.关键词
微藻/分离鉴定/培养/分子系统学Key words
microalga/isolation and identification/cultivation/molecular systematic analysis分类
海洋科学引用本文复制引用
鹿琳,杨官品,朱葆华,潘克厚..黄渤海夏季微藻调查[J].中国水产科学,2015,(4):828-836,9.基金项目
国家重点研究发展规划项目“微藻能源规模化制备的科学基础(2011CB200900)”子课题“能源微藻优良藻种(株)选育原理与综合评价体系(2011CB200901)” （2011CB200900）
