50种常用香料对铜绿微囊藻的生态毒性效应

为探究香料对铜绿微囊藻生长的影响，以常用的50种典型香料为供试目标物，测定不同暴露浓度下对藻生长的影响，并选择了对藻的生长有显著抑制作用的4种香料2-甲氧基萘、麝香草酚、月桂烯和吲哚测定不同暴露浓度下对藻的叶绿素a、可溶性蛋白含量、抗氧化酶活性（超氧化物歧化酶SOD、过氧化氢酶CAT、过氧化物酶POD）以及丙二醛（MDA）含量的影响.结果表明，2-甲氧基萘、麝香草酚、月桂烯和吲哚在高浓度暴露下能显著抑制铜绿微囊藻的生长，生物量增长抑制率的半效应浓度E_yC₅₀值分别为1.81，1.26，0.55，1.40mg/L，表现出明显的剂量-效应关系.在1mg/L的处理浓度下，2-甲氧基萘和麝香草酚显著抑制铜绿微囊藻叶绿素a和可溶性蛋白的含量（P<0.0001）；2-甲氧基萘暴露导致SOD活性显著降低（P<0.0001），其他两种抗氧化酶则无显著影响（P>0.05）；麝香草酚显著抑制了POD活性（P<0.0001），月桂烯也可降低SOD活性（P<0.01）；经吲哚处理的铜绿微囊藻，POD和CAT的活性显著低于对照组（P<0.0001）.研究表明，这4种香料通过抑制藻细胞抗氧化酶活性，过量累积MDA，破坏叶绿素含量和功能，进而导致藻类生长异常.2-甲氧基萘、麝香草酚和吲哚属于芳香族化合物，月桂烯为烯烃类化合物，不同结构的香料对不同的抗氧化酶活性的影响也不一样.2-甲氧基萘为合成香料，麝香草酚、月桂烯和吲哚均从自然界中发现，但目前后三种香料大多通过人工合成制备.研究结果丰富了香料的生态毒理效应基础数据，为其生态风险评估提供了依据.由于具有独特的芳香气味，芳香族化合物成为了香料中的一大类，且被广泛应用.但是芳香环性质稳定、难降解，因此我们需要更多关注芳香类香料的生态安全性.

Ecotoxicological effects of 50 kinds of fragrance materials on Microcystis aeruginosa

In the present study, the 50 fragrance materials were performed to determine the ecological toxicity on Microcystis aeruginosa. The influence of four fragrance materials (2-methoxynaphthalene, thymol, myrcene and indole) on the content of chlorophyll a and soluble protein, superoxide dismutase (SOD) activity, catalase (CAT) activity and malondialdehyde (MDA) content were also studied. The results showed that 2-methoxynaphthalene, thymol, myrcene and indole can significantly inhibit the growth of Microcystis aeruginosa under high concentration exposure, and the half-effect concentration E_yC₅₀ value was 1.81, 1.26, 0.55 and 1.40mg/L, respectively, showing an obvious dose-effect relationship. At a treatment concentration of 1mg/L, 2-methoxynaphthalene and thymol significantly inhibited the content of chlorophyll a and soluble protein (P<0.0001). Exposure to 2-methoxynaphthalene resulted in a significant decrease in SOD activity (P<0.0001), the other two antioxidant enzymes had no significant effect (P>0.05); Thymol significantly inhibited POD activity (P<0.0001), and myrcene also reduced SOD activity (P<0.01). The activities of POD and CAT of Microcystis aeruginosa treated with indole were significantly lower than those of the control group (P<0.0001). Studies showed that these four fragrance materials inhibited the antioxidant enzyme activity, accumulate excessive MDA, and destroied the content and function of chlorophyll, which in turn leads to the abnormal growth of algae. 2-methoxynaphthalene, thymol and indole are aromatic compounds, and myrcene was an olefin. The difference in structure of the four fragrance compounds resulted to the different effects on antioxidant enzymes. 2-Methoxynaphthalene was a synthetic fragrance. Although thymol, myrcene and indole were all natural flavors, they were mostly prepared by artificial synthesis. The current findings will enrich the fundamental data for evaluating the risk and toxicity of fragrance materials on the ecosystems. Because of their unique aromatic odor, aromatic compounds have become a large category of fragrance materials and are widely used. However, the aromatic ring is stable and difficult to degrade, so we need to pay more attention to the ecological safety of the fragrance materials with aromatic ring structure.