五价砷胁迫处理对普通小球藻的急性毒性效应  

ACUTE TOXIC EFFECT OF ARSENATES ON CHLORELLA VULGARIS

作　　者：李立杰 彭梦 杨帆[1,2] 余佳妮 金巍 谭凤霞 柴毅[1,2] LI Li-Jie;PENG Meng;YANG Fan;YU Jia-Ni;JIN Wei;TAN Feng-Xia;CHAI Yi(Engineering Research Center for Wetland Ecology and Agricultural Utilization,Ministry of Education,Yangtze University,Jingzhou 434025,China;College of Agriculture/College of Animal Science,Yangtze University,Jingzhou 434025,China)

机构地区：[1]长江大学湿地生态与农业利用教育部工程研究中心,荆州434025 [2]长江大学农学院/动物科学学院,荆州434025

出　　处：《水生生物学报》2022年第9期1374-1381,共8页Acta Hydrobiologica Sinica

基　　金：长江大学湿地生态与农业利用教育部工程研究中心开放基金资助。

摘　　要：为探究重金属砷在水域生态系统中的毒性作用及机制,以典型浮游植物指示种普通小球藻(Chlorella vulgaris)为试验对象,通过设置不同浓度As^(5+)(0、0.1、0.5、1、1.5和2 mg/L)研究其对普通小球藻的藻密度、叶绿素a含量、细胞膜通透性、蛋白(TP)含量、活性氧自由基(ROS)含量、丙二醛(MDA)含量、总抗氧化能力(T-AOC)、总超氧化歧化酶(T-SOD)活性、三磷酸腺苷酶(ATP)活性和超微结构的影响。研究结果表明,在96h胁迫内,各浓度As^(5+)处理组对普通小球藻的生长均有抑制作用,其中2 mg/L处理组抑制率最高,为52.9%,96h-IC50为1.94 mg/L。各处理组对藻细胞Chl.a含量也均有抑制作用,其中2 mg/L处理组最低,仅为对照组的31.4%。As^(5+)浓度为1.5和2 mg/L时,藻细胞TP和ATP含量显著降低,MDA含量为对照组的2倍和2.6倍,细胞膜通透性高于对照的1.7倍和2倍。2 mg/L处理组ROS含量显著增加,为对照组的4.0倍,刺激藻细胞产生氧化应激,T-AOC和T-SOD活性显著增加,为对照组的2.8倍和1.6倍。透射电镜(TEM)结果显示,As^(5+)2 mg/L处理组会破坏藻细胞内部结构,造成胞质空泡化,类囊体片层结构断裂,叶绿体结构紊乱等现象。这表明高浓度As^(5+)对普通小球藻细胞膜和主要细胞器的结构与功能具有破坏性,同时普通小球藻为应对污染物胁迫机体会产生氧化应激。在As^(5+)浓度低于1.5 mg/L时普通小球藻生理生化指标所受影响相对较小。研究揭示了典型指示种普通小球藻在As^(5+)环境胁迫中的生理生化反应,为水环境中重金属污染的修复及制定相关环境标准提供基础数据,进而实现水域生态系统的可持续发展与利用。In order to explore the toxicity and mechanism of heavy metals arsenic in aquatic ecosystem,Chlorella vul-garis,a typical phytoplankton indicator species,was used as the experimental object.Different concentrations of As^(5+)(0,0.1,0.5,1,1.5 and 2.0 mg/L)were used to study the effects of As^(5+)on the density,chlorophyll a content,cell mem-brane permeability,reactive oxygen species(ROS)content,malondialdehyde(MDA)content,total antioxidant capa-city(T-AOC),total protein(TP)content,total superoxide dismutase(T-SOD)activity,ATP activity and ultrastructure of C.vulgaris.The results showed that all concentrations of As^(5+)could inhibit the growth of C.vulgaris within 96h,and the inhibition rate of 2 mg/L treatment group was the highest(52.9%).The IC50 of 96h was 1.94 mg/L.The Chl.a con-tent of algae cells was also inhibited in all treatment groups,among which,the treatment group of 2 mg/L was the lo-west which was only 31.4%of the control group.When the concentration of As^(5+)was 1.5 and 2 mg/L,the content of TP and ATP decreased significantly.The content of MDA was 2 times and 2.6 times higher than that of the control group,and the cell membrane permeability was 1.7 times and 2 times higher than that of the control group.The content of ROS in 2 mg/L treated group increased significantly,which was 4.0 times of that in control group.The activities of T-AOC and T-SOD in algal cells stimulated by oxidative stress were 2.8 times and 1.6 times higher than those in control group.The results of transmission electron microscope showed that the group treated with 2 mg/L As^(5+)could destroy the internal structure of algae cells,resulting in cytoplasmic vacuolation,lamellar structure fracture of thylakoids and chloroplast structure disorder.The results showed that high concentration of As^(5+)was destructive to the structure and function of cell membrane and main organelles of C.vulgaris.At the same time,C.vulgaris produced oxidative stress in response to pollutant stress.The concentration of As^(5+)below 1.5 mg/L had no sign

关 键 词：重金属砷 急性毒性效应 抗氧化酶 超微结构 普通小球藻 

分 类 号：Q178.1[生物学—水生生物学]