A(sⅢ)和A(sⅤ)对小球藻(Chlorella sp).的生长影响研究

Toxicity of Arsenic Species on Growth of Green Microalgae Chlorella sp.

砷是广泛存在于自然界中最常见的毒性污染物,包括土壤,沉积物,水体,大气层,甚至生物体,毒性极强。环境中砷的污染严重威胁人类的健康,已被视为一个全球性的公共卫生问题。为了研究砷对小球藻的生长影响,文章通过实验室培养方式,选取了6个不同浓度的As(Ⅲ()0.5、1.0、2.0、5.0、10.0、20.0 mg/L)和As(Ⅴ()1.0、5.0、10.0、20.0、50.0、100.0 mg/L)的培养处理,以在680 nm下小球藻的吸光度(OD680)作为衡量因子,对小球藻Chlorella sp(.100 ai)在不同浓度砷离子的培养液中的细胞密度进行了试验,整个实验共进行了7 d。结果表明,As(Ⅲ)和As(Ⅴ)浓度分别在10.0 mg/L和20.0 mg/L以上时抑制100 ai细胞生长,导致其密度下降。用概率统计方法计算得到A(sⅢ)对100 ai的96 h半数有效抑制浓度EC50值为25.79 mg/L。参照藻类生长抑制评价标准,A(sⅢ)对100 ai的毒性比A(sⅤ)大。

Arsenic as the most common toxic pollutants in environment, is existing in soil, sediment, water, atmosphere and even organism. A serious threat to human health of arsenic pollution in environment has been recognized as a global public health problem. To study the toxicity of arsenic to microalgae, the toxicity of As （III） and As （ V ） concentration on growth of Chlorella sp.（ 100 ai） in laboratory was studied. Series of 50mL flaks containing the prepared Chlorella sp.（ 100 ai） culture were incubated at 25 ℃ for 7 d under different As（llI） concentrations（0.5,1.0,2.0,5.0,10.0,20.0 mg/L）and As（ V ） concentrations（ 1.0,5.0,10.0,20.0,50.0,100.0 mg/L）. After that the biomass was determined. Results showed that As（Ⅲ） and As（V） was significantly influenced by As（l]I）（〉10.0 mg/L） and As（V）（〉20,0 mg/L）. Higher As（ III ） and As（ V ） concentration would suppress its growth, resulting in a lower biomass. In the test, As（ III ）＇s EC50 was 25.79 mg/L, and toxicity of As（ Ⅲ） on 100 ai was bigger than that of As（V）.