四溴双酚A(TBBPA)对中肋骨条藻的毒性效应研究

为研究四溴双酚A(tetrabromobisphenol A,TBBPA)对海洋微藻的毒性效应,本文设置五个不同浓度组(0、1.0、5.0、10.0、20.0 mg·L-1)进行中肋骨条藻(Skeletonema costatum)培养实验,在96 h内取样分析其光合色素含量、可溶性蛋白含量、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性的变化。结果表明,较低浓度组(1.0和5.0 mg·L-1)叶绿素a、叶绿素c和类胡萝卜素含量48 h之前被显著诱导,最大值出现在24 h;较高浓度组(10.0和20.0 mg·L-1)三种色素含量在48 h之前被显著抑制,24 h达最低值;72 h之后各浓度组均恢复到对照组水平。不同浓度TBBPA胁迫下,中肋骨条藻的可溶性蛋白含量、SOD活性和MDA含量一般被显著诱导,SOD活性和MDA含量在72 h和96 h时随TBBPA浓度升高而增加。虽然1.0 mg·L-1TBBPA对中肋骨条藻生长不具有可观测效应,但已影响到其生理生化指标。目前海水中TBBPA浓度较低,尚不会对中肋骨条藻产生毒性影响。

Toxic Effects of Tetrabromobisphenol A (TBBPA) on Skeletonema costatum

To study the toxic effect of tetrabromobisphenol A (TBBPA) on marine microalgae, Skeletonema costatum was exposed to five different concentrations (0, 1.0, 5.0, 10.0, and 20.0 mg?L^-1) of TBBPA. The contents of photosynthetic pigments, soluble proteins, and malondialdehyde (MDA), and the activities of superoxide dismutase (SOD) were monitored within a 96 h period. The results showed that in the lower-concentration groups (1.0 and 5.0 mg?L^-1 of TBBPA), the contents of three pigments (chlorophyll a and c, and carotene) were induced till 48 h with a maximum value at 24 h. In the higher-concentration groups (10.0 and 20.0 mg?L^-1 of TBBPA), the pigments contents were inhibited till 48 h with the lowest values at 24 h. After 72 h, pigments contents in all the exposed groups were similar to the control. In most of the cases, the contents of soluble protein and MDA, and the activities of SOD showed significant induction in all the test groups. SOD activity and MDA content increased with increasing TBBPA concentration at 72 h and 96 h. Although 1.0 mg?L^-1 of TBBPA showed no effects on the growth of S. costatum, it did affect the physiological and biochemical parameters of the diatom. Currently, the TBBPA concentration in seawater is not high enough to cause toxic influence on S. costatum.