多酚对真核微藻的重金属抗性影响及其机制  

Effects and mechanisms of polyphenols on heavy metal resistance of eukaryotic microalgae

作　　者：张庭廷 周瑾[1] 李诚 ZHANG Ting-ting;ZHOU Jing;LI Cheng(Yuanpei College of Shaoxing University,Shaoxing 312000,China;College of Life Sciences,Anhui Normal University,Wuhu 241000,China)

机构地区：[1]绍兴文理学院元培学院,浙江绍兴312000 [2]安徽师范大学生命科学学院,安徽芜湖241000

出　　处：《中国环境科学》2023年第6期3158-3165,共8页China Environmental Science

基　　金：国家自然科学基金资助项目(41977402)。

摘　　要：以真核微藻斜生栅藻为试验对象,对其在重金属Pb^(2+)胁迫下,添加焦性没食子酸(PA)后的生物量变化及其机制进行了探究.结果表明:作用第4d,10.0mg/L单独Pb^(2+)对斜生栅藻的抑制率为73.1%,但在Pb^(2+)胁迫的同时添加不同浓度PA(1.0,5.0,10.0,15.0mg/L),可见明显的低促高抑现象,1.0~10.0mg/L PA添加组抑制率显著低于单独Pb^(2+)胁迫组,P<0.05.其机制研究表明,Pb^(2+)可严重损害藻细胞的结构,增加细胞的氧化压力,在早期诱导抗氧化酶如超氧化物歧化酶(SOD)、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽-S-转移酶(GST)的显著升高;而添加PA后,除最高浓度组(15mg/L),其余各组4种抗氧化酶活力在实验测定时间内均保持在较高水平,尤其是5.0~10.0mg/L组,其光合效能以及对Pb^(2+)的吸收率较单独Pb^(2+)胁迫组均有显著性提高,P<0.05,且细胞的形态结构也相对完整.推测一定浓度PA抵消或保护藻细胞受Pb^(2+)攻击的机制一方面可能与PA对重金属的螯合作用有关,减少了Pb^(2+)的毒性,提高了斜生栅藻的光合效能;另一方面,PA促进斜生栅藻对Pb^(2+)吸收能力,可能与其增强了藻细胞的抗氧化能力、维持了藻细胞形态结构的相对完整.已知PA对蓝藻有强烈抑制作用,因此,PA可成为重金属污染物以及富营养化水体复合重金属污染生物去除的重要潜在物质.The biomass of the eukaryotic microalgae Scenedesmus obliquus under Pb^(2+)stress with pyrogallic acid(PA)and its mechanism were investigated.The results showed that the inhibition rate of 10.0mg/L Pb^(2+)alone on S.obliquus was 73.1%on the 4th day,but when Pb^(2+)experiment groups were added with different concentrations of PA(1.0,5.0,10.0,15.0mg/L)at the same time,and the inhibition rates of 1.0~10.0mg/L PA groups were significantly lower than that of Pb^(2+)alone groups(P<0.05).The mechanism studied indicated that Pb^(2+)could seriously damage the structure of S.obliquus and increase the oxidative stress of the cells,and induce the significant increase of antioxidant enzymes such as superoxide dismutase(SOD),glutathione reductase(GR),glutathione peroxidase(GSH-Px)and glutathione S-transferase(GST)in the early stage.After adding PA groups,the activities of four antioxidant enzymes in all groups except the highest concentration group(15mg/L PA)were kept at a higher level during the test time,especially in the 5.0~10.0mg/L PA groups,the photosynthetic efficiency and the absorption rate of Pb^(2+)were significantly higher than that in the Pb^(2+)alone stress group(P<0.05)and the morphology and structure of the cells were less damaged than that of lead alone stress group.It is speculated that the mechanism of counteracting or protecting S.obliquus from Pb^(2+)attack at a certain concentration of PA may be related to the chelation of heavy metals by PA,which reduces the toxicity of Pb^(2+)and improves the photosynthetic efficiency of S.obliquus;on the other hand,PA may promote the Pb^(2+)absorption capacity of S.obliquus by enhancing its antioxidant capacity.It is known that PA has strong inhibitory effect on cyanobacteria,therefore,it can become an important potential material for biological removal of heavy metal pollutants and complex heavy metal pollution in eutrophic water.

关 键 词：Pb^(2+)污染 富营养化 焦性没食子酸 斜生栅藻 铜绿微囊藻 

分 类 号：X171.5[环境科学与工程—环境科学]