铜绿微囊藻与小球藻对低温和黑暗的响应与恢复

RESPONSES AND RESTORATION OF THE WATERBLOOM-FORMING CYANOBACTERIUM MICOCYSTIS AND A GREEN ALGA CHLORELLA UNDER DARKNESS AND LOW TEMPERATURE

  • 摘要: 研究以水华蓝藻铜绿微囊藻(Microcystis aeruginosa PCC 7806)与绿藻小球藻(Chlorella sp. FACHB-31)为研究对象, 探讨低温和黑暗对其生长、色素含量、最大光化学效率(Fv/Fm)、丙二醛(MDA)含量及过氧化氢酶活性的变化。结果表明, 30d的低温和黑暗处理, 显著降低了铜绿微囊藻和小球藻的叶绿素a浓度, 增加了单位细胞类胡萝卜素含量。在低温黑暗条件下, 铜绿微囊藻的MDA含量及CAT活性均显著增加, 而小球藻变化不明显。30d低温黑暗处理, 铜绿微囊藻的存活率为54.6%, 显著高于小球藻的31.3%。当恢复正常温度与光照, 2种藻均迅速生长。这些结果表明低温黑暗影响了微囊藻和小球藻的生理特性。在低温黑暗处理下, 微囊藻的Fv/Fm显著降低, 而小球藻则保持较为恒定的Fv/Fm, 表明微囊藻通过降低自身光合活性来渡过冬季低温黑暗的条件, 而小球藻在低温黑暗条件下仍保持较高的光合活性。

     

    Abstract: The growth, pigment content, maximum variable fluorescence (Fv/Fm), malondialdehyde (MDA) content, and antioxidant enzyme activity were investigated in Microcystis aeruginosa PCC 7806 and a green alga, Chlorella sp. FACHB-31, which were cultured under darkness and at a low-temperature in the present study. After a 30-d incubation under darkness and at a low temperature, chlorophyll a showed a significant decrease and the carotenoid unit content significantly increased in Microcystis and Chlorella. The MDA content and catalase (CAT) activity exhibited significant changes in Microcystis, while MDA content and CAT activity in Chlorella did not change markedly. Additionally, the survival rate of Microcystis was 54.6%, which is higher than that of Chlorella (31.3%). When returning to normal temperature and illumination, both algae showed a rapid growth. These results suggest that Microcystis survived by reducing its metabolic activity, but that Chlorella maintained a stable high metabolic activity under dark, low temperature winter conditions.

     

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