广玉兰提取物对铜绿微囊藻抑制作用的机制研究

The inhibitory mechanism of Magnolia grandiflora linn extracts on Microcystis aeruginosa

采用前期研究发现的可显著抑制铜绿微囊藻的广玉兰正己烷和正丁醇提取物,对其抑藻机制进行初步研究。研究发现,经广玉兰提取物处理后,藻细胞的叶绿素a含量显著减少;超氧化物歧化酶（SOD）活性先升后降;细胞膜透性显著增强,最高值达到对照组的7~8倍。同时,藻细胞的超微结构也相应地发生改变,具体表现为：细胞变形,质膜皱缩甚至断裂,中央拟核区不明显直至消失,这与叶绿素a含量减少的结果相呼应,与SOD活性和细胞膜透性的变化相关联;叶绿素类囊体片层呈细线状,排列松散无序。2种广玉兰提取物的抑藻作用有所不同,主要是因为广玉兰提取物对铜绿微囊藻的抑制作用是多种物质协同作用的结果。利用铜绿微囊藻的生理指标和超微结构相结合的方法,可以更好地解释和推导抑藻机制。

Two extracts of Magnolia grandiflora linn,hexane extract and butanol extract,were found having strong inhibitory effects on Microcystis aeruginosa by our previous studies.In order to probe the anti-algal mechanism of these two extracts,the content of chlorophyll-a,superoxide dismutase（SOD）,membrane permeability and ultrastructure of Microcystis aeruginosa that treated by this two extracts were investigated.The results showed that content of chlorophyll-a was declined rapidly,the SOD activity of algal cell was slightly increased first and then presented a urgent decline,the membrane permeability was increased significantly,with the highest permeability value was 7-8 time of that of control group.Accordingly,the ultrastructure of alga cell was also changed obviously,TEM photographs showed that the cell was destroyed severely with cell membrane wrinkled or even cracked,and pith nucleoid area was unobvious.The thylakoid lamella with linear structures was dispersed in cytoplasm messily.The function of these two extracts was different in alga inhibition,for inhibition process was the results of comprehensive actions.These results suggested that the method to give consideration to both growth indexes and ultrastructure makes it easier to understand antialgal mechanism.