久效磷对海洋微藻细胞的活性氧伤害

DAMAGE OF ACTIVE OXYGEN TO MARINE MICROALGA CELLS BY MONOCROTOPHOS

于 1 994年 8月— 1 995年 1 2月运用生态毒理学和生物化学实验方法对有机磷农药———久效磷对海洋微藻的毒性机理进行了研究。结果表明 ,随着久效磷胁迫时间的延长 ,3种海洋微藻 :扁藻、叉鞭金藻和三角褐指藻细胞的膜脂过氧化产物丙二醛 (MDA)含量不断提高 ,与此同时 ,3种微藻细胞的电解质外渗率也相应地增加。这说明在久效磷的胁迫压力下 ,微藻细胞内过量的活性氧引起细胞膜的膜脂过氧化伤害 ,导致细胞膜透性增加 ,电解质大量外渗 ,微藻细胞严重受害 。

Experiments were carried out in laboratory to measure effects of monocrotophos on three marine microalga with ecotoxicology and biochemistry methods from August, 1994 to December, 1995. Three marine microalga—? 玃latymonas sp., Dicrateria sp. and Phaeodactylum tricornutun were cultured in f/2 medium for 72 hours under monocrotophos stress, malondiadehyde (MDA) content and membrane permeability of the microalgae were examined at an intervals of 12 hours by centrifugation, collection and extraction. During the experiment lipid peroxidation became stronger and the content of MDA increased with stress time in three microalga, but there were differences among the three microalga in MDA changes, MDA content did not change much in the first 24 hours and increased obviously after 24h in Platymoas sp., while MDA content increased gradually in Dicrateria sp. and phaeodactylum tricornutum. Moreover, MDA change in Platymonas sp. was more distinct than that in the other two microalga. Meanwhile, the permeability of cell membrane in the three marine microalga increased, a lot of electrolytes were released. The membrane permeability increase in Platymonas sp. was more obvious than that in the other two microalga. So we conclude that damage of active oxygen can possibly result in growth inhibition or even death of algal cells.