有机配体对铜胁迫下铜绿微囊藻生长的影响

Effect of Organic Ligands on Distribution of Copper in Microcystis aeruginosa and the Content of Pigment

室内利用MA培养液,研究了在0.5mg·L-1铜的胁迫下,不同配体对铜绿微囊藻(Microcystisaeruginosa)的生长、叶绿素a含量及铜在细胞内外分配的影响。结果表明,EDTA、NTA和DTPA均会促进铜绿微囊藻的生长,EDTA可显著增加藻类的生长速度,NTA和DTPA可延长其对数生长期;3种配体的存在均显著增加了铜绿微囊藻的叶绿素a含量,其中EDTA的促进作用最大,NTA和DTPA次之;EDTA显著降低了铜绿微囊藻胞内和胞外富集量,NTA次之,而DTPA对Cu2+的在细胞内外的分布影响不大。

The growth, the content of Chla and distribution of copper among intracellular and extracellular of Microcystis aeruginosa FACHB526 in MA culture medium containing different organic ligands were studied in laboratory exposed to 0.5 mg·L^-1 Cu^2＋. Before the beginning of experimentation, we accounted the quantity of organic ligands which could join completely the copper in MA culture medium and added ligands to MA culture medium before sterilization. The biomass of algae was measured daily during the process of experiment, but the content of Chla and distribution of copper among intracellular and extracellular of Microcystis aeruginosa was determined in the end. The results showed that EDTA, NTA and DTPA all could enhance the growth of Microcystis aeruginosa, but only EDTA enhanced the growth speed of algae and NTA and DAPA extended their logarithm growing period. The content of Chla increased notably in the presence of three kinds of organic ligands, and the promoting effect of EDTA was most, DTPA took the second place and NTA was less relatively. The great mass of copper was adsorbed by the exterior of algae when exposed to 0.5mg·L^-1 Cu^2＋, the adsorption of copper in and out the cells of Microcystis aeruginosa was significantly reduced in the presence of EDTA, NTA had very little effect, and adsorptive capacity of the exterior of algae was increased relatively when DTPA existed.