Algae Body Type Metallothionein (MT-Like) Study On Heavy Metal-induced Response

Heavy metal contamination became more serious than before with the development of industry in recent years. As one of the key pollutants in the environment, more and more studies focused on the environmental destruction and human health issues caused by heavy metal contamination. Heavy metal can be enriched by alga by surface adsorption and-SH complextion, the enrichment ability can be improved through the synthesis of MT-Like, as well as the toxic resistance ability. Provide scientific basis for the use of alga as a good choice for bioremediation of heavy metal pollution in water body.1. Alga were cultured under heavy metal stress condition under laboratory conditions, the heavy metal enrichment patterns and content of synthesized MT-Like were investigated. The main research contents and conclusion of our study are as follows:The determination of heavy metal concentration in alga and its heavy metal enrichment:Alga was cultured under different heavy metal concentration conditions (0.001mmol/L>0.01mmol/L.0.1mmol/L.1mmol/L ZnCl2,CuCl2and CdCl2solution). The correlation between single element and culture time were investigated, Expression and variation under different heavy metal stress conditionsAlga was cultured under heavy metal stress conditions, take samples after0,1,3,5,7and10days treatment. Samples were treated by freeze drying, grind and microwave digestion, working parameter of ICP-MS were also optimized. Good linear relation between elements, high degree of precision, good performance between replicates were achieved under optimal conditions. The results showed that alga have high heavy metal enrichment ability, the accumulation amount was increased and the enrichment coefficient was decreased with the elevation of heavy metal concentration. After washed by0.5mol/L EDTA, the amount of heavy metal in alga between7days and10d have no difference, however, the total amount of heavy metal were increased.2. Extraction, purification and characterization of MT-Like in alga:alga were cultured under ZnCl2stress conditions, extracting solution were obtained after homogeneously stirring, digestion and centrifugation. The ultraviolet absorption pattern of MT-Like was analyzed. The ultraviolet spectrum of MT-Like is very similar to BSA and Zn-MTs. The molecular weight of MT-Like were analyzed by SDS-PAGE. The results of ESI-MS analysis showed that the molecular weight of MT-Like is6.5KDa. In addition, HPLC-ICP-MS, dual detector and ICP-MS were used to analysis the heavy metal combined with MT-Like. The exact content of combined heavy metal were obtained, with a further determination of MT-like concentration.3. The inductive effect of heavy metal on MT-Like:MT-Like induced by the combined effect of Zn-Cu, Zn-Cd and Cu-Cd were compared with these induced by Zn,Cu, Cd,separately. The the initial value, expression characterization, variation and the relationship between MT-Like concentration and culture time were analyzed. The results showed that the expression of MT-Like under the induction of Zn+Cu. Zn+Cd and Cu+Cd at1,3,5,7and10days were lower compared to the conditions when alga were cultured under the stress of Cu, Cd and Zn respectively, indicate the antagonistic effect of Cu, Cd and Zn in the induction of MT-Like.The structure, content variation, and heavy metal combine ability of MT-Like were investigated, the synergistic and antagonism effect of heavy metal on the induce of MT-Like were also analyzed. The toxic resistance ability and detoxication effect of alga were evaluated, our study provide scientific basis for the use of alga as a good choice for bioremediation of heavy metal pollution in water body.