分子氢和氧对受高温胁迫蓝藻固氮活性的影响

Ａｎａｂａｅｎａ７１２０经高温处理后，固氮活性下降，对氧的敏感度增大，增大程度随氧浓度增高而递增。高温胁迫下，分子氢与对正常条件下生长的蓝藻一样可以削弱或消除氧对固氮的伤害，氢的此种行为在光照下和黑暗中表现相似，其良好作用比正常生长蓝藻显著，添加光合抑制剂。ＣＯ２或Ｎ２时亦如何。有外源蔗糖时，氢的良好作用不表现。经ＣＯ或Ｃ２Ｈ２处理的蓝藻，氢在其固氮活性受氧伤害时的良好作用消失。

EFFECT OF MOLECULAR HYOROGEN AND OXYGEN ON NITROGENASE ACTIVITY OF BLUE-GREEN ANABAENA 7120 DRIVEN BY STRESS OF HIGH TEMPERATURE

In this paper we found that:1.The nitrogenase activity of Anabaena 7120decreased and was more sensitive to oxygen,when treated at high temperaturefor a short time. 2.The O_2-sensitivity of nitrogenase activity of Anabaena drivenby stress of high temperature was increased with the increase of O_2-concentrationin test system.3. Molecular hydrogen could protect nitrogenase activity from damageby oxygen in Anabaena injured by high temperature.4.The protection of nitroge-nase activity by molecular hydrogen against O_2 inactivation in Anabaena influencedby high temperature was more obvious than that in normal algae cells.5.Theprotection of nitrogenase activity by molecular hydrogen against O_2-inactivationin Anabaena influenced by high temperature was occured when the photosyntheticinhibitors,such as DNP or CCCP,or CO_2 or N_2 were presented respectively, butnot when external sucrose presnted.6.When algae cells injured by high temper-ature were preincubated in the dark in 60-70%C_2H_2 and 30-40% Ar atmosphereor in 10% CO the protective action of hydrogen was weakened or disappeared.