Wang Mengyun, Chen Pei, Wang Hongxia, Deng Qiong, Zhang Xiaonan, Yuan Guoqing, Jiang Mixue, Zheng Lingling, Hu Zixuan, Gu Zemao, Tikhonenkov Denis V, Gong Yingchun
Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Microorganisms. 2025 Apr 28;13(5):1016. doi: 10.3390/microorganisms13051016.
Herbivorous protistan grazers are ubiquitous and abundant in marine and temperate freshwater environments. However, little is known about the algivorous ciliates and their feeding habits in outdoor mass algal cultures. In this study, we report on one hypotrich ciliate, identified as , from the outdoor mass culture of in Arizona, USA. A long-term field survey revealed that this species often occurs in culture in spring and summer, and can graze very heavily on cells. By isolating cells and then observing them via light microscopy and electron microscopy, detailed information about the morphology, ultrastructure, excystment process, and feeding characteristics of the ciliate was obtained. Specifically, it seems that has a range of different strategies for excystment, and the sharp change in the ion concentration in the environment around the cyst results in osmotic shock, which likely facilitates the excystment. Feeding experiments revealed that preferred to graze on chlorophytes as well as the diatom and had no interaction with chrysophytes or cyanobacteria. Molecular phylogenetic analysis based on the SSU rRNA gene sequence indicated that both the genus and the species are non-monophyletic. The information obtained from this study will help advance our understanding of the biodiversity and ecological function of , and will also be very useful in the development of early warning systems and control measures for preventing or treating this contaminant in microalgal mass cultures.
食草性原生动物食草者在海洋和温带淡水环境中无处不在且数量众多。然而，对于室外大规模藻类培养中的食藻纤毛虫及其摄食习性却知之甚少。在本研究中，我们报告了一种来自美国亚利桑那州室外大规模培养的 中的下毛目纤毛虫，鉴定为 。一项长期的实地调查显示，该物种在春季和夏季经常出现在 培养物中，并且能够大量捕食 细胞。通过分离 细胞，然后通过光学显微镜和电子显微镜对其进行观察，获得了有关该纤毛虫的形态、超微结构、脱囊过程和摄食特征的详细信息。具体而言， 似乎有一系列不同的脱囊策略，并且囊肿周围环境中离子浓度的急剧变化会导致渗透休克，这可能有助于脱囊。摄食实验表明， 更喜欢捕食绿藻以及硅藻 ，并且与金藻或蓝细菌没有相互作用。基于小亚基核糖体RNA（SSU rRNA）基因序列的分子系统发育分析表明， 属和 种均非单系。从本研究中获得的信息将有助于增进我们对 的生物多样性和生态功能的理解，并且在开发用于预防或处理微藻大规模培养中这种污染物的预警系统和控制措施方面也将非常有用。
