在光、暗及高温下氧与鱼腥藻7120固氮的关系  

RELATIONSHIP BETWEEN OXYGEN AND NITROGEN FIXATION OF ANABAENA 7120 IN LIGHT, DARKNESS AND AT HIGH TEMPERATURE (38—40℃)

作　　者：王业勤[1] 何家菀[1] 章德萍[1] 黎尚豪[1] 

机构地区：[1]中国科学院水生生物研究所

出　　处：《水生生物学报》1987年第3期247-254,共8页Acta Hydrobiologica Sinica

摘　　要：鱼腥藻7120从光转暗不同时间后,照光检测固氮活性的损失速度与氧量直接相关。在黑暗12小时后,复光时的活性恢复被氧霉素、氯化铵或38—40℃空气氧所阻遏,黑暗中生成的酶易被氧失活。在光下和黑暗中短时暴露于不同氧压时,黑暗中氧引起固氮活性的下降比光下快得多。抗坏血酸大大减少高氧引起的失活,高温可能增加固氮酶活性对氧的敏感性。在光下100%O_2处理120分钟,活性没有进一步下降,也没有活性的恢复,没有观察到构型保护。讨论了环境条件与氧保护的关系。When photoautotrophically-grown Anabaena culture was transferred to darkness/air, the reduction rate of nitrogen-fixing activity was proportional to oxygen concentration. When dark-treated culture (in air for 12 hrs) was reilluminated, the recovery of activity was depressed by chloramphenicol, NH_4 or by 38—40℃/air. This implies that the preformed nitrogenase was inactivated by atmo-spheric oxygen in darkness. When Anabaena cells were exposed to different oxygen tensions for a short time (30 min) in light or in darkness, the decline of activity in darkness was much greater than that in light. Ascorbate could alleviate the inactivation at higher oxygen content, whereas high temperature may enhance the oxygen sensitivity of nitrogenase. Treatment of cells with 100% O_2 for up to 120 min did not result in further inactivation, nor did it show any recovery of the activity. Therefore, no comformational protection has been observed. Relationship between oxygen protection and environmental conditions is discussed.

关 键 词：固氮活性 高氧 不同时间 暴露 观察 鱼腥藻 霉素 黑暗 固氮酶活性 环境条件 

分 类 号：Q949[生物学—植物学] S144.3[农业科学—肥料学]