重金属铅离子(Pb^(2＋))对两株螺旋藻生长影响的研究

Pb^(2+) impacts on growth of two Spirulina strains

以来自两个不同企业产业化的螺旋藻作为出发藻株A、藻株B,从生物量、藻胆蛋白、可溶性蛋白、半数致死浓度4个方面研究藻株对重金属铅离子(Pb2+)的耐受性,为解析耐受机理积累研究基础。实验结果表明,两株藻对Pb2+的耐受性存在明显差异,藻株B比藻株A对铅的耐受性强。藻株A:Pb2+浓度低于1 mg/L,促进其生长;Pb2+浓度为10～40 mg/L,对其无明显影响;Pb2+浓度大于50 mg/L时,抑制其生长;Pb2+浓度为100 mg/L,藻丝体降解死亡;96 h半数致死浓度(EC50)为61.66 mg/L。藻株B:Pb2+浓度低于20 mg/L,对其无明显影响;Pb2+浓度为20 mg/L,促进其生长;Pb2+浓度大于50 mg/L,抑制其生长;Pb2+浓度为100 mg/L,藻丝体降解死亡;96 h半数致死浓度(EC50)为72.44 mg/L。当Pb2+浓度为20 mg/L时,藻蓝蛋白(PC)和水溶性蛋白均具有较高的积累量,与其正常生长情况相似。

To investigate the impacts of heavy metal ions（Pb2＋） on spirulina biomass,phycobiliprotein,soluble proteins,and the median lethal concentration,a comparative study between two industrialized spirulina strains（A and B） was conducted.Experimental data indicated that the response of strain A was quite different from strain B with different Pb2＋,and that strain B was more tolerant to Pb2＋ than strain A.With Pb2＋ concentration lower than 1 mg/L,growth of strain A was promoted;with Pb2＋ concentration from 10 to 40 mg/L,no obvious effect was found;with Pb2＋ concentration more than 50 mg/L,inhibited;with Pb2＋ concentration 100 mg/L,died;the 96 h-EC50 of strain A was 61.66 mg/L.With Pb2＋ concentration lower than 20 mg/L,no obvious effect was found on strain B;with Pb2＋ concentration 20 mg/L,strain B growth was promoted;with Pb2＋ concentration more than 50 mg/L,inhibited;with Pb2＋ concentration 100 mg/L,died;the 96 h-EC50 of strain A was 72.44 mg/L.When Pb2＋ concentration was 20 mg/L,content of phycocyanin and water-soluble proteins were higher,consistent with the normal growth.