低剂量多次暴露焦性没食子酸的抑藻效果初步研究  

Preliminary Study on Allelopathic Inhibition of Cyanobacteria:From the View of Low Dose-Repetitious Exposure of Pyrogallic Acid

作　　者：孙雪梅[1,2] 刘碧云[1] 周巧红[1] 高云霓[1] 葛芳杰[1] 鲁志营[1,2] 吴振斌[1] 

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,湖北武汉430072 [2]中国科学院大学,北京100049

出　　处：《环境科学与技术》2014年第1期65-69,189,共6页Environmental Science & Technology

基　　金：国家自然科学基金(51178452,50909091,31123001);国家“十二五”水专项(2012ZX07101007-005);淡水生态与生物技术国家重点实验室开放课题(2013FB20)

摘　　要：目前实验室对化感物质抑藻效应的研究多在EC50水平上进行,而水生植物释放化感物质具有微量、持续性的特征。本研究试图探索在化感物质暴露总量相同的前提下,全剂量一次性暴露与低剂量多次暴露在抑藻效果上是否存在差异,以便为今后开展进一步研究提供依据。实验以能够诱导藻细胞产生活性氧进而引发氧化损伤的化感物质焦性没食子酸作为研究对象,以细胞密度、细胞内O2·ˉ、H2O2及OH·的产生水平和细胞膜损伤情况作为指标,比较了低剂量多次暴露(0.25 mg/L×4次×5 d,间隔4 h)与单次暴露(5 mg/L)对铜绿微囊藻的致毒效应。实验结果显示,就生长速度而言:单次暴露组<低剂量多次暴露组<对照组;而低剂量多次暴露下样品藻细胞内的O2·ˉ、H2O2及OH·水平则呈逐步升高趋势(P<0.01),且当累计暴露量仅为设计暴露总量的一半时就超过了单次暴露下的相应水平,到实验的第5天分别达到相应单次暴露组的1.10(O2·ˉ)和1.06(H2O2及OH·)倍;而膜损伤的情况,单次暴露与低剂量多次暴露均能造成藻细胞膜的损伤,且相对膜损伤水平(%)实验后期还维持在160%上下。从上述实验结果看出,低剂量多次暴露的方式很可能具有比单次暴露更强的持续抑藻能力,因而开展对低剂量多次暴露条件下化感抑藻效应的研究十分重要,其结果将更接近水生植物释放化感物质的低剂量、持续性特征。Previous studies on allelopathic inhibition of algae are mainly performed at concentrations near the level of EC50, but the allelochemicals are released by submerged aquatic macrophytes with low concentration and continuity characteristics. This research tried to compare the differences in algae-inhibition effect between full single dose exposure and low dose-repetitious exposure under the same total exposure dose. The pyrogallic acid （PA） which could induce ROS formation and oxidative damage in the cells of phytoplankton was used as the test allelochemical. Cell density, O2·-, H2O2 and OH· production and membrane damage of Microcystis aeruginosa were used as test index to compare the toxic effect between full single dose exposure （Group I ） and low dose-repetitious exposure（Group II ） by the total dose of 5 mg/L PA. Results showed the growth rate of Microcystis aeruginosa was Group I 〈Group II 〈control; O2·-, H2O2 and OH· level of Group II exhibited significant increases （P〈0.01） and gradually exceeded respective level of Group I, and ROS level of Group lI were 1.10 （O2·- level） and 1.06 （H2O2 and OH· level） folds of that of Group I at day 5. Both fuU dose-single exposure and low dose-repetitious exposure could cause membrane damage of Microcystis aeruginosa, and the relative membrane-damage level （%） of Group I and II kept around 160% till end of the experiment. Results suggested that lowdose-repetitious exposure may have greater potential in algae-inhibition than full dose-single exposure. Moreover, the results also suggested that the toxicological effect of the low dose repetitious and continuous long term exposure of allelochemical which closer to releasing characteristics in natural aquatic ecosystem should be concerned in the study of mechanism of allelopathic inhibition of algal in future.

关 键 词：低剂量多次暴露 焦性没食子酸 铜绿微囊藻 细胞密度 活性氧 细胞膜损伤 

分 类 号：X172[环境科学与工程—环境科学]