Liu Xudong, Zhao Jinli, Feng Jia, Lv Junping, Liu Qi, Nan Fangru, Xie Tao, Xie Shulian
School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, Taiyuan, China.
J Eukaryot Microbiol. 2022 Jan;69(1):e12872. doi: 10.1111/jeu.12872. Epub 2021 Oct 29.
Members of coccoid green algae have been documented in various extreme environments. In this article, a unicellular green alga was found to slowly grow in high concentration (3.6 g/L) and pure calcium chloride solution in the laboratory. It was successfully cultured and a taxonomic study combined approaches of morphological and molecular methods was conducted to determine its classification attribution, which was followed by a preliminary physiology research to explore its unique tolerance characteristics against calcium chloride stress. The strain was identified as Parachlorella kessleri by very similar morphology and the same phylogenetic position. The morphological differences among the three species in genus Parachlorella were then discussed and the characteristic traits of absent or thin mucilaginous envelop and mantel-shaped chloroplast for P. kessleri were supported. In addition, the almost strictly spherical shape of adult cells could further distinguish the P. kessleri from the other two species. The tolerant characteristics to CaCl stress for this strain were confirmed and the limit concentration was revealed as between 2000 and 4000 times than the standard BG11 culture concentration. Therefore, this P. kessleri strain is expected to be a good material to explore the mechanism of resistance to calcium ions stress for eukaryotic microbiology.
在各种极端环境中都有关于球形绿藻成员的记录。在本文中，在实验室里发现一种单细胞绿藻能在高浓度（3.6克/升）的纯氯化钙溶液中缓慢生长。它被成功培养，并采用形态学和分子方法相结合的分类学研究来确定其分类归属，随后进行了初步的生理学研究，以探索其对氯化钙胁迫的独特耐受特性。通过非常相似的形态和相同的系统发育位置，该菌株被鉴定为凯氏拟小球藻。然后讨论了拟小球藻属中三个物种之间的形态差异，并支持了凯氏拟小球藻不存在或薄的黏液包膜以及斗篷状叶绿体的特征。此外，成年细胞几乎严格的球形形状可以进一步将凯氏拟小球藻与其他两个物种区分开来。证实了该菌株对氯化钙胁迫的耐受特性，其极限浓度比标准BG11培养浓度高2000至4000倍。因此，这种凯氏拟小球藻菌株有望成为探索真核微生物对钙离子胁迫抗性机制的良好材料。
