环境因子对三峡库区铜绿微囊藻(Microcystis aeruginosa)群体形成影响及其形态特征  

Effects of environmental factors on Microcystis aeruginosa colony formation and morphological characteristics in Three Gorges Reservoir

作　　者：安强[1] 李雪琴[1] 王沙[1] 黄晓龙[1] 蒋韵秋[1] 

机构地区：[1]重庆大学三峡库区生态环境教育部重点实验室,重庆400045

出　　处：《湖泊科学》2017年第2期378-388,共11页Journal of Lake Sciences

基　　金：中央高校基金项目(CDJZR14215501)资助

摘　　要：为揭示微囊藻群体形成机理,为有效防治水华暴发提供依据,以三峡库区铜绿微囊藻(Microcystis aeruginosa)为研究对象,研究N、P浓度,Ca^(2+)浓度,光强,温度对铜绿微囊藻生长、胞外多糖(EPS)合成和群体微囊藻形成的影响,并对比分析了单细胞和群体微囊藻的形态特征.研究发现当N≤100 mg/L、P≤5 mg/L时,铜绿微囊藻生物量和EPS合成量随着N、P浓度增加而增加;适宜浓度的Ca^(2+)(65 mg/L)有利于藻生长,EPS产量随着Ca^(2+)浓度增加而降低,过高浓度的Ca^(2+)在刺激微囊藻细胞分泌EPS的同时可能会促进其溶解,Ca^(2+)和EPS均对微囊藻群体形成起桥架粘结作用;光照和温度对EPS合成有一定促进作用,且其促进效果均高于N、P和Ca^(2+)作用,20℃是同时满足微囊藻生长及EPS合成的最有利条件.群体细胞比单细胞周围的胶质鞘更加明显和清晰,多糖胶鞘表面有许多Ca^(2+)晶体,从微观角度可以确定Ca^(2+)在EPS合成及群体形成中起着重要作用.To reveal Microcystis aeruginosa colony formation mechanism and provide the basis for effectively controlling the algae blooming in the Three Gorges Reservoir region, impacts of N, P concentrations, Ca2＋ concentration, light intensity and temperature on the growth, extracellular polysaccharides synthesis and colony formation of the M. aeruginosa were investigated, and the mor- phological characteristics of single cells and M. aeruginosa groups were compared. The results showed that the biomass of M. aerug- inosa and EPS concentration increased with the increasing of N, P concentrations. The optimal Caz~ concentration for the growth of M. aeruginosa was 65 mg/L, and the EPS content decreased with the increasing of Ca2＋ concentration. High Ca2＋ concentrations might stimulate the ceils to secrete the EPS and simultaneously promote the EPS to be dissolved. Both Ca2＋ and EPS took the re- sponsibility for the colony formation of M. aeruginosa as the bridge bond action. Light and temperature played a role on the synthesis of the EPS, which were stronger than the promoting effects of N, P and Ca2＋concentrations. 20℃ was the most favorable tempera- ture conditions for the Microcystis growth and EPS synthesis. The surrounding gelatinous sheath of cells group was more obvious and clearer than the single cell. Many Ca2＋ crystals on the sheath surface of polysaccharide gums were observed. Thus, Ca2＋ played an important role in EPS synthesis and colony formation.

关 键 词：三峡库区 环境因子 铜绿微囊藻 形态特征 

分 类 号：X524[环境科学与工程—环境工程]