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[目的]以江苏海州湾常见微藻塔胞藻(Pyramidomonas delicatula)、塔玛亚历山大藻(Alexandrium tamarense)为受试藻,研究水环境中草甘膦对2种微藻的致毒胁迫效应。[方法]以叶绿素a含量、超氧化歧化酶(SOD)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量为指标,研究2种海洋微藻的生长及细胞内抗氧化系统对草甘膦致毒胁迫的响应。[结果]草甘膦质量浓度高于6.15 mg/L,对2种微藻表现出明显抑制作用,塔胞藻、塔玛亚历山大藻10.25 mg/L组培养至7 d,分别为对照组的5.9%、6.4%;96 h培养时间内,草甘膦对塔胞藻及塔玛亚历山大藻叶绿素a含量的影响表现在降低叶绿素a的合成量,呈现显著的质量浓度-剂量效应;低质量浓度草甘膦对2种微藻的SOD活性均表现诱导性上升,在10.25 mg/L恢复对照组水平;草甘膦对2种微藻的CAT活性表现微弱抑制;2种微藻体内MDA含量随草甘膦处理质量浓度增加而显著增长,塔胞藻、塔玛亚历山大藻在10.25 mg/L试验组达最高值,均为对照组16倍之多。[结论]高质量浓度(≥6.15 mg/L)的草甘膦可以有效抑制海洋微藻抗氧化酶活性,对塔胞藻、塔玛亚历山大藻具有强烈的致毒效应,不同的海洋微藻对农药残留致毒胁迫的响应存在较大的种属差异性。旨在提示农药污染对水环境破坏的严重性,揭示海洋微藻作为环境毒理学评价指标的潜在应用。
[Objective] The study aimed to study the virulent stress effects of glyphosate on two kinds of microalgae in water environment by using the common microalgae Pyrusomonas delicatula and Alexandrium tamarense in Haizhou Bay of Jiangsu Province. [Method] The contents of chlorophyll a, superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were taken as indexes to study the growth and intracellular antioxidant system of two marine microalgae Response to glyphosate toxicity. [Result] The concentration of glyphosate was higher than 6.15 mg / L, which obviously inhibited the growth of two microalgae. The culture of Phala seahorse and Alexandrium tamarense 10.25 mg / L for 7 d were 5.9 % And 6.4%, respectively. The effect of glyphosate on the content of chlorophyll a in Alexandrium tamarense and Alexandrium tamarense decreased with the increase of chlorophyll a in 96 h incubation period, showing significant mass concentration-dose effect. The activity of glyphosate on the two microalgae SOD activity showed an inductive increase in 10.25 mg / L to restore the control group levels; glyphosate on the two microalgae CAT activity showed weak inhibition; MDA content of two microalgae with the grass The mass concentration of glyphosate increased significantly with the increase of Phalaenopsis cells and Alexandrium tamarense in the experimental group of 10.25 mg / L, which were 16 times as much as the control group. [Conclusion] Glyphosate with high concentration (≥6.15 mg / L) could effectively inhibit the activity of antioxidant enzymes in marine microalgae, and had a strong toxic effect on Phalaenopsis and Alexandrium tamarense. Different pairs of marine microalgae The response of pesticide residues to toxic stress has larger species diversity. The purpose is to reveal the seriousness of pesticide pollution on the water environment and reveal the potential application of marine microalgae as environmental toxicology evaluation index.