汞胁迫下雪衣藻的生理活性及其藻源性有机物分析  

Responses of Physiological Activities and Algal Organic Matter of Chlamydomonas nivalis to Mercury Stress

作　　者：艾晓寒 涂晓杰 许萍萍 夏亦雪 毕永红[1] Ai Xiaohan;Tu Xiaojie;Xu Pingping;Xia Yixue;Bi Yonghong(State Key Laboratory of Freshwater Ecology and Biotechnology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院水生生物研究所,淡水生态与生物技术国家重点实验室,武汉430072 [2]中国科学院大学,北京100049

出　　处：《生态毒理学报》2023年第6期245-256,共12页Asian Journal of Ecotoxicology

基　　金：国家重点研发计划课题(2020YFA0907402)。

摘　　要：汞(Hg)可显著影响藻类生长增殖,但藻类对汞胁迫的响应特性尚不清楚。本研究以雪衣藻为材料,将其暴露于不同浓度Hg^(2+)中96 h,考察其在汞胁迫下的生理活性及其藻源性有机物(algal organic matter,AOM)特性。结果表明,雪衣藻对Hg^(2+)的耐受浓度为1 mg·L^(-1),随着Hg^(2+)浓度增加,雪衣藻生物量和生长受到显著影响。溶解性有机碳释放速率增加,胞外类蛋白质和类腐殖酸的含量升高,胞内类蛋白质先增高后降低,类腐殖酸先降低后升高;胞外有机质对Hg^(2+)亲和力表现为富里酸>类蛋白质,胞内则相反。雪衣藻生长、胞内外有机物含量和结构组成显著受汞胁迫的影响,AOM的动态变化是细胞对汞胁迫的响应,可增强自身耐受能力,缓解汞的毒性。本研究结果有助于理解藻类细胞对汞的解毒机制,认识AOM在藻类对抗汞胁迫中的作用。Mercury(Hg)can significantly affect algal growth and proliferation,but the response characteristics of a lgal cells to mercury stress is not clear.In this study,Chlamydomonas nivalis were selected and exposed to different Hg 2+concentrations for 96 h.Results showed that:algal cell’s tolerance concentration was 1 mg·L^(-1)Hg^(2+);algal b iomass and growth state were significantly affected by Hg^(2+)stress.With the increase of concentration of Hg^(2+),the dissolved organic carbon release rate increased,extracellular proteins-like and humic acids increased,intracellular proteins-like first increased and then decreased,and the sensitivity of extracellular organic matter to Hg^(2+)binding was in the order of fulvic acid>protein-like,variation of intracellular organic matter sensitivity was the opposite.The growth,intra-and extracellular organic matter content and structural composition were significantly affected by mercury stress,the dynamic change of algal organic matter was the cellular response to mercury stress,which can enhance its tolerance ability and alleviate the toxicity of mercury.The results contributed to understanding the algal cell’s detoxification mechanism to mercury stress.

关 键 词：汞 雪衣藻 毒性效应 藻源性有机物 

分 类 号：X171.5[环境科学与工程—环境科学]