摘要:
近年来，内陆和近海水体中的一种典型环境激素邻苯二甲酸二丁酯(DBP)含量显著上升，但其对海洋生态系统的影响并不明确。本研究选取7种海洋微藻为实验材料，包括1种甲藻(东海原甲藻Prorocentrum donghaiense)，2种定鞭藻(小普林藻Prymesium parvum和球形棕囊藻Phaeocystis globosa)，2种硅藻(中肋骨条藻Skeletonema costatum和三角褐指藻Phaeodactylum tricornutum)，以及1种隐藻(红胞藻Rhodomonus salina)和1种绿藻(海洋小球藻Chlorella sp.)，设置5个DBP暴露浓度(5、10、20、50、100 µg·L-1)，研究其对海洋微藻生长的影响，并探索DBP暴露对微藻抗氧化系统和光合系统的影响。结果表明：在所有暴露组中，球形棕囊藻、小普林藻、东海原甲藻、红胞藻、海洋小球藻生长速率显著增加；5~20 µg·L-1的DBP暴露下中肋骨条藻不受影响，50、100 µg·L-1下受到抑制；所有DBP暴露组对三角褐指藻没有显著影响。在50 µg·L-1 DBP暴露下，随着时间的延长，球形棕囊藻的SOD、CAT、MDA均表现出先升高后下降的趋势，第7天藻的叶绿素a、叶绿素b，类胡萝卜素含量较对照组分别增加了23%、10%、48%，球形棕囊藻光系统Ⅱ (PSⅡ)的最大光能转化效率(Fv/Fm)、PSⅡ的潜在活性(Fv/F0)、光合性能指数PI分别增加了4.8%、16%、69%。研究发现DBP对海洋微藻的影响具有种间差异性，能够显著促进有害赤潮藻球形棕囊藻的生长，近岸水体DBP含量的增加可能改变浮游植物群落组成，进而增加有害藻华暴发的风险。
Abstract:
In order to study the effects of DBP on the growth, antioxidant system and photosynthesis of marine algae, seven marine algae, including Prorocentrum donghaiense, Prymesium parvum, Phaeocystis globosa, Skeletonema costatum, Phaeodactylum tricornutum, Rhodomonus salina, and Chlorella sp. were exposed to DBP at concentration gradients of 5,10,20,50,100 μg·L-1 and a control. Chlorophyll fluorescence were measured each day. T-SOD, CAT, MDA pigment contents and chlorophyll fluorescence of P. globosa were determined during the experiment at concentration of 50 μg·L-1 DBP. Results showed that, growth of P. globosa, P. parvum, P. donghaiense, Chlorella sp. and R. salinawere significantly higher than the controls in all treatments (P<0.01). DBP had inhibition effect on S. costatum at 50 and 100 μg·L-1 treatments (P<0.01). There was no significant difference in all P. tricornutum treatments compared with the control. SOD, CAT activities and MDA values of P. globosa cultures increased at first and decreased subsequently during the experiments. At day 7, the contents of chlorophyll a, b and carotenoids were increased by 23%, 10%, and 48% respectively, and the maximal photochemical efficiency of PSⅡ (Fv/Fm), the potential activity of PSⅡ (Fv/F0) and performance index (PI) were also increased by 4.8%, 16%, and 69% respectively. DBP displayed species-specific influences on marine microalgae, and significantly promoted the growth of P. globosa. Increasing concentration of DBP at coastal water may change the community composition of phytoplankton and increase the risk of harmful algal blooms.
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