作　　者： ; ; ; ; ; ;

机构地区： 中国科学院南海海洋研究所

出　　处： 《热带海洋学报》 2006年第4期46-50,共5页

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.

关 键 词： 海洋蓝藻 固氮 阿特拉津 盐度 昼夜变化

领　　域： [生物学]