绿藻胞外聚合物对无机砷生物累积特征的影响  

Effects of extracellular polymeric substances on the bioaccumulation of inorganic arsenic by green microalgae

作　　者：黄飞 周昉 姜舒扬 张建英[1,2,3] HUANG Fei;ZHOU Fang;JIANG Shuyang;ZHANG Jianying(College of Environmental Science and Resources, Zhejiang University, Hangzhou , 310058 , China;Zhejiang Province Key Laboratory of Organic Pollution Process and Control, Hangzhou , 310058, China;National Demonstration Center for Experimental Environment and Resources Education (Zhejiang University), Hangzhou, 310058, China)

机构地区：[1]浙江大学环境与资源学院,杭州310058 [2]浙江省有机污染过程与控制重点实验室,杭州310058 [3]国家级环境与资源实验教学示范中心(浙江大学),杭州310058

出　　处：《环境化学》2019年第5期1021-1027,共7页Environmental Chemistry

基　　金：国家自然科学基金(21477103)资助~~

摘　　要：绿藻对无机污染物的净化作用受其自分泌胞外聚合物EPS影响.以EPS释放量高的蛋白核小球藻为绿藻代表,通过24 h短期As(Ⅲ)和As(V)的模拟水体暴露实验,研究绿藻对无机砷的生物累积特征及EPS影响.结果表明,在0-40 mg·L^-1 As(Ⅲ)和As(V)暴露浓度范围,蛋白核小球藻细胞内的砷累积速率随暴露浓度的增加而升高,其动力学拟合结果符合Michaelis-Menten酶促反应动力学方程. EPS与无机砷存在界面相互作用影响,无机砷暴露浓度升高可促进小球藻EPS分泌, EPS与砷累积速率之间呈现正相关线性关系(R^2> 0.900),主要影响成分是溶解态EPS.完整藻细胞与脱除胞外聚合物的活体细胞相比, As(Ⅲ)、As(V)暴露的最大吸附累积量分别增加30.6%和14.2%,而最大胞内累积量降低49.0%和31.0%. EPS与无机砷的微界面交互作用影响绿藻对砷污染的净化修复.Extracellular polymeric substances(EPS) self-produced by green algae influence its bio-purification of inorganic arsenic. Chlorella pyrenoidosa was chosen as the representative EPS-producing green algae to investigate bioaccumulative characteristics of inorganic arsenic and EPS effects, based on a 24 h short-term simulation exposure experiment to As(Ⅲ) and As(V). Results showed that the intracellular arsenic accumulation rate increased with the exposure concentration of As(Ⅲ) and As(V), and they matched well the Michaelis-Menten enzymatic reaction kinetic equation in the range of 0-40 mg·L^-1. Increasing inorganic arsenic promoted the production of algae EPS, especially soluble EPS, and a significantly linear relationship was observed between EPS secretion rate and intracellular arsenic accumulation rate(R^2 > 0.900). Compared to EPS-removed live cells, the maximum extracellular accumulation capacity of the intact algae cells for As(Ⅲ) and As(V) increased by 30.6% and 14.2%, while the maximum intracellular accumulation capacity reduced by 49.0% and 31.0%, respectively. The micro-interfacial interactions of algal EPS with inorganic arsenic impacts arsenic bioremediation.

关 键 词：无机砷 蛋白核小球藻 胞外聚合物 表面吸附 生物吸收 

分 类 号：X173[环境科学与工程—环境科学] X52