Torstensson Anders, Dinasquet Julie, Chierici Melissa, Fransson Agneta, Riemann Lasse, Wulff Angela
Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, SE-40530, Sweden.
Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, DK-3000, Denmark.
Environ Microbiol. 2015 Oct;17(10):3869-81. doi: 10.1111/1462-2920.12865. Epub 2015 May 7.
Due to climate change, sea ice experiences changes in terms of extent and physical properties. In order to understand how sea ice microbial communities are affected by changes in physicochemical properties of the ice, we used 454-sequencing of 16S and 18S rRNA genes to examine environmental control of microbial diversity and composition in Antarctic sea ice. We observed a high diversity and richness of bacteria, which were strongly negatively correlated with temperature and positively with brine salinity. We suggest that bacterial diversity in sea ice is mainly controlled by physicochemical properties of the ice, such as temperature and salinity, and that sea ice bacterial communities are sensitive to seasonal and environmental changes. For the first time in Antarctic interior sea ice, we observed a strong eukaryotic dominance of the dinoflagellate phylotype SL163A10, comprising 63% of the total sequences. This phylotype is known to be kleptoplastic and could be a significant primary producer in sea ice. We conclude that mixotrophic flagellates may play a greater role in the sea ice microbial ecosystem than previously believed, and not only during the polar night but also during summer when potential food sources are abundant.
由于气候变化，海冰在范围和物理性质方面都发生了变化。为了了解海冰微生物群落如何受到冰的物理化学性质变化的影响，我们使用16S和18S rRNA基因的454测序技术来研究南极海冰中微生物多样性和组成的环境控制。我们观察到细菌具有高度的多样性和丰富度，它们与温度呈强烈负相关，与卤水盐度呈正相关。我们认为，海冰中的细菌多样性主要受冰的物理化学性质控制，如温度和盐度，并且海冰细菌群落对季节和环境变化敏感。在南极内陆海冰中，我们首次观察到甲藻系统发育型SL163A10在真核生物中占主导地位，占总序列的63%。已知这种系统发育型具有盗食质体，可能是海冰中的重要初级生产者。我们得出结论，混合营养鞭毛虫在海冰微生物生态系统中可能发挥比以前认为的更大的作用，不仅在极夜期间，而且在夏季潜在食物来源丰富时也是如此。
