摘要
研究盐度、昼夜变化、温度及阿特拉津(光合系统Ⅱ抑制剂)对2种海洋固氮蓝藻Calothrixsp.strain(代号为MCT1)和Lyngbyasp.strain(代号为MCT6)固氮活性的影响。结果表明,MCT1在盐度10—48范围内具有相对较高的固氮活性,在盐度为30时固氮活性最高,达到0.687 2μmolC2H2.(g.h)-1;而MCT6随盐度改变固氮活性变化幅度较大,盐度为24时具有最高固氮活性,其活性为0.876 8μmolC2H2.(g.h)-1。MCT1和MCT6固氮活性的昼夜变化明显不同,具有异型胞的海洋固氮蓝藻MCT1白天的固氮活性明显高于夜晚;而无异型胞的MCT6最高固氮活性发生在晚上,白天固氮活性较低。一定浓度的阿特拉津通过抑制光合作用阻断能量和还原剂的提供,使藻体在较短时间内丧失固氮能力。加入阿特拉津后2种藻体的固氮活性与对照组相比有明显的变化,实验第3天开始MCT1的所有经阿特拉津处理的样品固氮活性丧失;MCT6经(50—1 000)×10-6阿特拉津处理的样品从实验第3天开始固氮活性完全消失。
The effects of salinity, alternation of light and dark, temperture and atrazine （a photosystem Ⅱ inhibitor, 2-chloro-4-ethylamino-6-isopropylamine-s-triazine） on nitrogen fixation rates of Calothrix sp. strain MCT1 and Lyngbya sp. strain MCT6 are studied. The results reveal that the nitrogenase activity can be detected over a wide range of salinity （10 to 48）. For Calothrix sp. strain MCT1, the maximum nitrogenase activity of 0. 6872μmol C2H2 · （g·h）^-1 occurs at salinity of 30; while for Lyngbya sp. strain MCT6, the maximum nitrogenase activity of 0. 8768μmol C2H2 ·（g ·h）^-1 occurs at salinity of 24. Since the addition of atrazine to plant samples can block the continuous supply of newly generated ATP and reductants which are required for nitrogen syntheses in the cells, certain concentration of atrazine can abolish nitrogen fixation of both Calothrix sp. strain MCT1 and Lyngbya sp. strain MCT6 within two days. The diel pattern of nitrogen activity of Calothrix sp. strain MCT1 is different from that of Lyngbya sp. strain MCT6. The filament cyanobacteria Calothrix sp. strain MCT1 has some special cells named heterocysts, and its photosynthesis and nitrogen fixation are spatially separated, with nitrogen fixation in heterocysts and photosynthesis in vegetative cells; while Lyngbya sp. strain MCT6 does not have heterocysts, photosynthesis and nitrogen fixation are usually temporally separated, with photosynthesis occurring during daytime and nitrogen fixation occurring either during nighttime or in light when photosynthesis is inhibited.
出处
《热带海洋学报》
CAS
CSCD
北大核心
2006年第4期46-50,共5页
Journal of Tropical Oceanography
基金
中国科学院知识创新工程项目(KSCX2-SW-132
KZCX3-SW-214)
国家自然科学青年基金项目(40006009)
中国科学院南海海洋研究所领域前沿项目(LYQY200303)
中国科学院生态系统研究网络台站研究基金
广东省科技计划项目(2004B60302004
2005B60301032)
广东省海洋药物重点实验室开放课题
中国科学院海洋研究所海洋生态与环境科学重点实验室开放基金
重大基础研究前期研究专项(2005CCA04800)
关键词
海洋蓝藻
固氮
阿特拉津
盐度
昼夜变化
marine cyanobacterium
nitrogen fixation
atrazine
salinity
alternation
作者简介
张燕英（1980-），女，山东省潍坊市人，博士研究生，主要从事海洋生态、微藻培养及生态生理研究。E-mail：amy0517@gmail．com．
