乳酸对铜绿微囊藻的抑藻效应及机理

The inhibitory effect of lactic acid on Microcystis aeruginosa and its mechanisms

以铜绿微囊藻为实验对象,研究了乳酸对铜绿微囊藻的抑藻效果及可能的抑藻机理.结果表明乳酸对铜绿微囊藻的生长有很强的抑制作用,72h,除最低浓度实验组对铜绿微囊藻的抑制率为60%外,其余浓度实验组的抑制率均达到了80%以上;在乳酸胁迫下,藻液中核酸和蛋白质含量增加,电导率上升,细胞中丙二醛(MDA)和氧自由基(O_2^(·-))含量增加,超氧化物歧化酶(SOD)活性下降;透射电镜图片显示,细胞的超微结构发生了明显改变.推测乳酸可能的抑藻机理是改变了藻细胞膜的通透性及其细胞结构,降低了其抗氧化能力,最终使得藻细胞裂解死亡.

The inhibitory effect and possible inhibitory mechanisms of lactic acid on M. aeruginosa were studied. The results showed that lactic acid had a strong inhibiting effect on the growth of M. aeruginosa, 72 h, except the inhibition rate of experimental group in lowest concentration was 60%, the rest inhibition rate of experimental group were reached more than 80%; under the stress of lactic acid, the contents of nucleic acid and protein, the electrical conductivity（EC） in M. aeruginosa supernatant all increased, the contents of malondialdehyde（MDA） and oxygen free radical（O_2^（·-）） of M. aeruginosa cells enhanced, the activity of superoxide dismutase（SOD） decreased, and transmission electron microscope photographs showed that ultrastructure of M. aeruginosa cells had changed obviously. All the results indicated that the possible inhibiting mechanisms were that lactic acid changed the permeability of M. aeruginosa membrane and the cell structure, decreased its antioxidant capacity, and caused the crack and death of the cell in the end.