本文關(guān)鍵詞：2,2’,4,4’-四溴聯(lián)苯醚（BDE-47）對兩種海洋微藻的毒性效應(yīng)研究　出處：《國家海洋局第一海洋研究所》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： BDE-47 海洋微藻 光合色素 超氧化物歧化酶(SOD) 丙二醛

【摘要】：多溴聯(lián)苯醚(polybrominated diphenyl ethers, PBDE)是一類具有生態(tài)風(fēng)險性的新型持久性有機污染物,自上世紀70年代以來被用作溴化阻燃劑和添加劑,廣泛應(yīng)用于保護電子產(chǎn)品、紡織品和泡沫等塑料制品。多溴聯(lián)苯醚可以通過滲出或者揮發(fā)等方式進入到環(huán)境中,且具有的遷移性、蓄積性和持久性等特點,這些特點決定了這類化合物不僅在環(huán)境中長期殘留,而且可以進行生物富集和放大,從而影響生物體的正常生理活動,其對海洋環(huán)境的影響也引起了國內(nèi)外研究人員的廣泛關(guān)注,因此評價研究PBDEs在環(huán)境中的行為十分必要。但是,目前有關(guān)PBDEs對海洋微藻的毒性效應(yīng)鮮見報道,因而無法客觀評價此類化合物的海洋生態(tài)風(fēng)險性。微藻是海洋生態(tài)系統(tǒng)的初級生產(chǎn)者,其種類多樣性和生物量影響海洋生態(tài)系統(tǒng)的結(jié)構(gòu)功能,在食物鏈中具有非常重要的作用,同時具有對毒物敏感、繁殖快和易獲得等優(yōu)點,能在短時間內(nèi)得到污染物對其種群及世代的影響研究,是較為理想的指示生物。本文選用了環(huán)境中含量較高、分布較廣泛的PBDEs的代表性同系物—2,2’,4,4’-四溴聯(lián)苯醚(2,2',4,4'-Tetrabromodiphenyl Ether, BDE-47)作為研究對象,以常見海洋微藻叉鞭金藻(Dicrateria inornata)、中肋骨條藻(Skeletonema costatum)、三角褐指藻(Phaeodactylum tricornutum)、小球藻(Chlorella vulgaris)為受試生物,研究了BDE-47對四種海洋微藻的急性毒性效應(yīng),得到BDE-47對四種微藻的96 h半效應(yīng)濃度(96 h-EC5o)。在此基礎(chǔ)上,研究了不同濃度BDE-47作用下叉鞭金藻(Dicrateria inornata)、中肋骨條藻(Skeletonema costatum)的葉綠素?zé)晒鈪?shù)(Fv/Fm、Fv/Fo、rETR、ΦPSII)、光合色素(葉綠素a (Chl-a)、葉綠素c(Chl-c)和類胡蘿卜素(Car))含量、可溶性蛋白含量、超氧化物歧化酶(Superoxide dismutase, SOD)活性和丙二醛(Malondialdehyde, MDA)含量的變化,以及藻細胞形態(tài)的變化,以探討B(tài)DE-47對海洋微藻的致毒機理。主要研究結(jié)果如下：(1)BDE-47對叉鞭金藻和中肋骨條藻的96 h-EC5o值分別為163 μg·L-1和648648μg·L-1, BDE-47對叉鞭金藻屬于極高毒性物質(zhì),而對中肋骨條藻屬于高毒性物質(zhì)；在可助溶濃度范圍內(nèi)未能檢測到BDE-47對三角褐指藻和小球藻96h-EC50。BDE-47對四種微藻的毒性大小順序為：叉鞭金藻中肋骨條藻三角褐指藻)小球藻。(2)中肋骨條藻的光合特性指標Fv/Fm、Fv/Fo、rETR、ΦPSII均隨著BDE-47濃度升高而顯著降低；BDE-47對叉鞭金藻的光合特性指標影響與濃度和脅迫時間有關(guān)。低濃度BDE-47對叉鞭金藻的Fv/Fm、Fv/Fo值起促進作用,而高濃度的BDE-47對叉鞭金藻的Fv/Fm、Fv/Fo、OPSII則起抑制作用,顯著低于對照組；24 h時叉鞭金藻的rETR、ΦPSII隨著BDE-47濃度的升高而降低,而rETR值到48 h和72 h恢復(fù)到對照組水平,ΦPSII值則到96 h恢復(fù)到對照組水平。(3)低濃度(50μg·L-1～100 μg·L-1)的BDE-47對中肋骨條藻的Chl-a、Chl-c、Car含量的無顯著影響,而中、高濃度(200μg·L-1～600μg·L-1)污染物的影響則體現(xiàn)為Chl-a、Chl-c、Car的含量顯著增加,且隨著BDE-47濃度的增加而增加；低濃度(25 μg·L-1～50μg·L-1)的BDE-47對叉鞭金藻的Chl-a、Car含量沒有顯著影響,能促進Chl-c的合成,而高濃度(150μg·L-1～200μg·L-1)的BDE-47能夠抑制三種色素的合成。(4)各濃度組BDE-47對中肋骨條藻的可溶性蛋白含量呈誘導(dǎo)-抑制的時間變化趨勢,而對叉鞭金藻則主要表現(xiàn)為誘導(dǎo)作用。48h內(nèi)各濃度組中肋骨條藻和叉鞭金藻SOD酶活性均被顯著誘導(dǎo)；72h后較低濃度組兩種微藻SOD酶活性均恢復(fù)到對照組水平,而較高濃度BDE-47污染下,中肋骨條藻SOD活性被顯著誘導(dǎo),叉鞭金藻SOD活性則被顯著抑制。BDE-47脅迫72h后,各濃度組中肋骨條藻和叉鞭金藻MDA含量均顯著高于對照組,并且誘導(dǎo)率隨BDE-47濃度增加而增加。(5)掃描電鏡結(jié)果顯示,隨著BDE-47濃度的增大,兩種藻細胞形態(tài)均受到破壞,出現(xiàn)細胞破碎、失水、鞭毛脫落等現(xiàn)象。透射電鏡結(jié)果表明,對照組叉鞭金藻細胞器清晰均勻分布在基質(zhì)中,而BDE-47處理下,葉綠體皺縮,類囊體排列散亂,線粒體數(shù)目增加,細胞基質(zhì)變渾濁,表明細胞器受到嚴重損傷。
[Abstract]:Polybrominated diphenyl ethers (polybrominated diphenyl, ethers, PBDE) is a kind of ecological risk model of persistent organic pollutants, since the last century since 70s has been used brominated flame retardants and additives, widely used in electronic products, textiles and foam plastic products. PBDEs can seep through volatilization or etc. enter into the environment, and the migration, accumulation characteristics and durability, these characteristics determine the compounds in the environment not only long-term residue, but also for bioaccumulation and amplification, from normal physiological activities and influence of the organism, its impact on the marine environment has aroused extensive attention at home and abroad the staff, therefore the study on Evaluation of PBDEs behavior in the environment is necessary. However, the PBDEs of marine microalgae toxicity is rarely reported, and thus cannot be objective evaluation Marine ecological risk of such compounds. Microalgae are the primary producers of the marine ecosystem, the species diversity and biomass of the structure and function of the marine ecosystem, plays a very important role in the food chain, and is sensitive to poison, and easy to obtain the advantages of fast breeding, can influence on the study of pollutant the population and generations in a short period of time, is an ideal biological indicator. In this paper, the environment with high content, widely distributed PBDEs representative 2,2 ', homologues of 4,4' - four polybrominated diphenyl ether (2,2', 4,4'-Tetrabromodiphenyl, Ether, BDE-47) as the research object, taking the common marine microalgae Dicrateria (Dicrateria inornata), Skeletonema costatum (Skeletonema costatum), phaeodactylumtricornutum (Phaeodactylum tricornutum) (Chlorella vulgaris), Chlorella as the test organism and the effects of BDE-47 on four kinds of Marine Micro The acute toxicity of algae, get half effect concentration of 96 h BDE-47 to four kinds of microalgae (96 h-EC5o). On this basis, the effects of different concentrations of BDE-47 under the action of Dicrateria (Dicrateria inornata), Skeletonema costatum (Skeletonema costatum) the chlorophyll fluorescence parameters (Fv/Fm, Fv/Fo, rETR, PSII), photosynthetic pigments (chlorophyll a (Chl-a), chlorophyll C (Chl-c) and carotenoid (Car) content), soluble protein content, superoxide dismutase (Superoxide dismutase, SOD) activity and malondialdehyde (Malondialdehyde, MDA) content changes, and changes in algal cell morphology, to investigate the BDE-47 the toxic mechanism of marine microalgae. The main results are as follows: (1) BDE-47 on Dicrateria and Skeletonema costatum 96 h-EC5o = 163 g L-1 and 648648 g L-1, BDE-47 of Dicrateria belongs to high toxic substances, which belongs to the high toxicity of Skeletonema. Algae 鐗╄川錛涘湪鍙姪婧舵祿搴﹁寖鍥村唴鏈兘媯，

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