滇池水华束丝藻(Aphanizomenon flos-aquae)对低氮的生理响应  

Physiological response to low nitrogen level in Aphanizomenon flos-aquae from Lake Dianchi

作　　者：吴艳龙[1,2] 郑凌凌[1] 李林[1] 殷大聪[3] 代龚圆[1] 宋立荣[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,武汉430072 [2]中国科学院大学,北京100049 [3]长江水利委员会长江科学院,武汉430010

出　　处：《湖泊科学》2014年第1期131-136,共6页Journal of Lake Sciences

基　　金：NSFC云南联合基金项目(U-0833604);国家水体污染控制与治理科技重大专项项目(2013ZX07102-005);国家自然科学基金项目(51279011)联合资助

摘　　要：通过对分离的滇池北部海埂湾春季蓝藻水华时期的两株水华束丝藻(Aphanizomenon flos-aquae)进行研究,探讨了滇池水华束丝藻在低浓度硝酸盐下的生长特征,以及无氮条件下藻丝异形胞的诱导分化过程与固氮能力.实验结果表明:两株水华束丝藻在各浓度硝酸盐中均能够生长,并且生物量能够增加到较高水平.硝态氮浓度高时水华束丝藻的生物量也较高,但是硝酸盐浓度超过0.5 mg/L时,各组生物量无显著性差异.无氮BG-11培养基培养条件下,水华束丝藻可以快速分化形成异形胞,含有异形胞的藻丝比例在3 d以后即可达50%左右,最高可以达72%,之后开始下降,但是仍能维持较高比例.水华束丝藻在无氮条件下通过异形胞固定的氮元素从第7 d开始逐渐增加,在生长43 d后,培养基中增加的氮浓度接近30 mg/L.Two strains of Aphanizomenon flos-aquae were isolated from spring cyanobacterial blooms in Haigeng Bay which located in the northern part of Lake Dianchi.Both the growth characteristics and heterocyst formation as well as nitrogen fixation ability of A.flos-aquae were investigated under different low concentrations of sodium nitrate,and in nitrogen-free culture medium,respectively.The results showed that A.flos-aquae strains were able to grow in the BG-11 medium with various low concentrations of nitrate,and the biomass reached a very high level.The biomass increased with the nitrate-nitrogen concentration increasing,but there was no significant difference when nitrate-nitrogen concentration was above 0.5 mg / L.Induction of heterocyst differentiation was rapid when A.flos-aquae was cultured in N-deficient BG-11 medium,and after reaching a maximum of 72% approximately,the filament with heterocyst began to swing lower.The total nitrogen in nitrogen-free medium increased gradually as nitrogen fixation proceed,and nitrogen concentration was close to 30 mg / L at day 43.

关 键 词：滇池 水华束丝藻 硝态氮 异形胞 固氮 

分 类 号：X173[环境科学与工程—环境科学]