波吉卵囊藻对重金属铬的耐受性研究

Analysis of heavy metal chromium tolerance of Oocystis borgei

为了研究波吉卵囊藻对重金属铬的耐受性,向波吉卵囊藻(Oocystis borgei)培养液中加入不同质量浓度的重铬酸钾,铬(Ⅵ)浓度依次为:0、2.5、5.0、7.5、10.0、12.5、15.0 mg/L。每天定时测定波吉卵囊藻藻细胞密度、叶绿素a含量以及藻蛋白含量。结果表明波吉卵囊藻在铬浓度≤5.0 mg/L时,随着培养时间的增长,藻细胞密度、叶绿素a含量和蛋白含量均增加,且高于空白对照组指标;波吉卵囊藻在铬离子浓度5.0~7.5 mg/L时,随着培养时间的增长,藻细胞密度增多,叶绿素a含量增加;铬离子浓度≤7.5 mg/L时,蛋白含量随着铬离子浓度的增加;也相应增加;波吉卵囊藻在铬离子浓度>10.0 mg/L时,随着培养时间的增长,藻细胞密度不变,叶绿素a含量与蛋白含量增加显著小于空白组。实验得出低浓度铬(Ⅵ)(≤5.0 mg/L)能够促进波吉卵囊藻生长,提高藻胆蛋白和叶绿素a含量,当铬(Ⅵ)浓度超过7.5 mg/L时,藻胆蛋白含量降低,波吉卵囊藻生长受到抑制,并且随着铬离子浓度的增加,抑制作用增大;总体而言,铬离子对波吉卵囊藻生长表现为双重作用,波吉卵囊藻对铬有一定的耐受性。

In order to study the tolerance of Oocystis borgei to heavy metal chromium, different concentration chromium （VI） （0, 2. 5, 5.0, 7.5, 10. 0, 12. 5 and 15.0 mg/L） was added to the medium. The indexes are recorded, such as O. borgei cell density, chlorophyll content and algal protein content everyday to explore the tolerance of O. borgei to heavy metal chromium. The results showed that, when the chromium （ VI ） concentration under 5.0 mg/L, the indexes of algal density, chlorophyll content and protein content of O. borgei increased with the increase of chromium （ V[ ） concentration. When the concentration of chromium （VI） was 0. 5 - 7.5 mg/L, the density of algal cells and the content of chlorophyll were all increased, . When the concentration of chromium （ VI ） was under 7. 5 mg/L, the protein content of 0. borgei increased with the increase of chromium （ VI ） concentration. When the concentration of chromium （ VI ） was over 10. 0 mg/L, the activity of O. borgei increased with the increase of chromium （ VI ） culture （less than 5.0 mg/L）, the growth of O. borgei was promoted and the content of phycobiliprotein and chlorophyll was increased. The concentration of chlorophyll and protein increased significantly. When the concentration of chromium （VI） exceeds 7.5 rag/L, the content of phycobiliprotein decreased, the growth of O. borgei was inhibited, and the inhibitory effect increased with the increase of chromium concentration. The low concentration of chromium （ VI ） （less than 5.0 mg/L） promote O. borgei growth, improve the O. borgei protein and the content of chlorophyll, when the concentration of chromium （VI） is more than 7.5 mg/ L, the O. borgei protein content is decreased, O. borgei growth is restrained, and with the increase of chromium concentration, the inhibition increase ; For conclusion, chromium ion have two - sidedness to the O. borgei growth, O. borgei has a certain tolerance to chromium.