a-亚麻酸对赤潮异弯藻生长的抑制作用

探讨了a-亚麻酸对赤潮异弯藻(Heterosigma akashiwo)生长的抑制作用,并从细胞膜渗透性、抗氧化酶系和光合放氧量等方面研究了其抑制机理.结果表明,a-亚麻酸对赤潮异弯藻有明显的抑制作用,其第7d的IC50为2.4μL/L.在a-亚麻酸作用下,细胞内Na+、K+、Mg2+和Ca2+浓度随着实验的进行受到不同程度的影响,在36h后都出现明显的下降;藻细胞内可溶性蛋白质含量下降,超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT).在8h时明显高于对照组,之后逐渐下降,到36h时低于对照组;丙二醛含量(MDA)表征了脂质过氧化强度和膜系统受损程度,其在12h时明显高于对照组,之后慢慢下降;藻细胞的光合放氧量呈逐渐下降趋势.结果表明,a-亚麻酸通过改变细胞膜透性和自由基反应,从而破坏藻细胞的结构,进而达到抑藻的效果.

Inhibitory effects of a-linolenic acid on the red tide microalgae Heterosigma akashiwo

The inhibitory effects of α-linolenic acid on the red tide microalgae Heterosigma akashiwo were studied.The possible algicidal mechanism was investigated through the membrane permeability,antioxidant enzymes,and photosynthesis of the microalgae cells.Results showed that the growth of H.akashiwo was inhibited obviously by high concentrations of α-linolenic acid.The 7-day IC50 was 2.4μL/L.The membrane permeability was destroyed by the α-linolenic acid treatment with the intracellular concentration of Na+,K+,Mg2+ and Ca2+ decreased significantly after 36h.The soluble protein content of algal cells decreased during the experimental process with the antioxidant enzymes superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) content elevated at 8h,then decreased significantly gradually until 24h,and finally lower than the control group at 36h.The malondialdehyde(MDA) content indicated the lipid peroxidation stress and the membrane damage degree by the a-linolenic acid treatment.It significantly elevated at 12h,and then decreased gradually until 36h.The photosynthetic oxygen evolution decreased during the period of 8h.The results of this study revealed that the α-linolenic acid could destroy the structure of red tide algal cells by changing the cell membrane permeability and free radical reactions,and in this way the inhibitory effects on the algae were achieved.