A(sⅢ)和A(sⅤ)对小球藻(Chlorella sp).的生长影响研究

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。

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

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(Ⅲ) 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(Ⅲ)(>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).