不同浓度Cd^(2+)对酿酒酵母的毒害作用研究  

Research on the Toxicity of Cd^(2+) of Different Concentrations to Saccharomyces cerevisiae

作　　者：王锐诚 向兴[1,2] 胡婷[1,2] 张圆圆[2] 

机构地区：[1]中国地质大学(武汉)生物地质与环境地质国家重点实验室,湖北武汉430074 [2]中国地质大学(武汉)环境学院,湖北武汉430074

出　　处：《安全与环境工程》2014年第6期92-97,共6页Safety and Environmental Engineering

基　　金：国家自然科学基金项目(41072253)

摘　　要：以"模式生物"——酿酒酵母(Saccharomyces cerevisiae)为载体,通过测定酵母细胞的生物量、活细胞/死细胞的计数比值以及胞外聚合物(EPS)的含量,研究了不同浓度的Cd2+(Cd2+浓度分别为0.0mg/L、0.1mg/L、0.5mg/L、1.0mg/L、2.0mg/L、8.0mg/L)对酿酒酵母的毒害作用。试验结果表明:当Cd2+浓度小于或等于0.1mg/L时,活细胞/死细胞的计数比值随着时间的推移分别降低了7.86和8.37,在0.5 mg/L、1.0 mg/L和2.0mg/L的Cd2+浓度下,活细胞/死细胞的计数比值则分别上升了3.35、5.64和0.89,8.0mg/L浓度的Cd2+则会完全抑制酵母细胞的增殖,活细胞/死细胞的计数比值波动在0.86~1.11之间;同时,随着Cd2+浓度的上升,酵母细胞的生物量会逐渐减少,0.1mg/L浓度的Cd2+对酵母细胞生物量无明显影响,0.5~8.0mg/L浓度的Cd2+可使酵母细胞生物量比不含Cd2+的培养基分别下降了7.01%、35.14%、59.89%和96.86%;此外,0.5 mg/L和1.0mg/L浓度的Cd2+能显著刺激酵母细胞分泌更多的EPS,增幅分别为20.26%和7.54%。上述结果表明酵母细胞在一定的Cd2+浓度下可以通过提高EPS的产量来抵御Cd2+对细胞的毒性作用。This paper studies the＂model organism＂Saccharomyces cerevisiae and measures the biomass of cells,live/dead ratio and yield of extracellular polymeric substance（EPS）in YPD batch cultures with Cd^2＋gradient of0.0 to 8.0mg/L.The results show that the live/dead ratio of S.cerevisiae cell reduces by 7.86 and 8.37 respectively with the concentrations of Cd^2＋not more than 0.1mg/L.When the concentrations of Cd^2＋are 0.5mg/L,1.0mg/L and 2.0mg/L,the trend reverses and the live/dead ratio increases by 3.35,5.64 and 0.89.The proliferation of S.cerevisiaecell is inhibited completely when the concentration of Cd^2＋is 8.0mg/L,and the live/dead ratio ranges from 0.86 to 1.11 stably.In addition,the biomass of S.cerevisiae cell decreases with the increase of Cd^2＋concentrations obviously.It decreases insignificantly when the concentration of Cd^2＋is 0.1mg/L.When the concentrations of Cd^2＋are 0.5mg/L,1.0mg/L,2.0mg/L and 8.0mg/L,compared with 0.0mg/L the biomass of S.cerevisiae cell reduces by 7.01%,35.14%,59.89%and 96.86%respectively.Besides,Cd^2＋with concentrations of 0.5mg/L and 1.0mg/L can stimulate the secretion of EPS by S.cerevisiae cell,and the growing rates are 20.26% and 7.54%respectively.The results above show that S.cerevisiaecell could withstand the toxicity of Cd^2＋by secreting more EPS to a certain extent.

关 键 词：酿酒酵母 镉离子(Cd^2+) 生物量 胞外聚合物(EPS) 毒理作用 

分 类 号：X703.1[环境科学与工程—环境工程] X75