Ni2+胁迫对铜绿微囊藻（Microcystis aeruginosa）和集胞藻（Synechocystis sp.）的生长和光合色素的影响(Effects of Nickel on Growth and Photosynthetic Pigments of Microcystis aeruginosa and Synechocystis sp.)

光合作用是蓝藻生长繁殖的生理基础,研究重金属胁迫下蓝藻光合色素的变化和响应,有助于揭示其受害机理.在实验室无菌纯培养条件下,研究了不同浓度Ni2+处理下铜绿微囊藻和集胞藻的生物量和光合色素随时间的变化趋势.结果表明:浓度为5mg·L-1～25mg·L-1的Ni2+对M.aerugonisa的生长有抑制作用,随着处理剂量的增加和处理时间的延长,抑制作用愈加显著;在短时间(24h)内,Ni2+对Synechocystissp.的生长没有显著影响,随胁迫时间延长呈现出抑制作用;Ni2+处理M.aerugonisa至24h及Synechocystis sp.至48h时,藻细胞光吸收能力整体上受到明显抑制;5mg·L-1～25mg·L-1的Ni2+胁迫下,M.aerugonisa和Synechocystis sp.的叶绿素a含量随胁迫时间延长而降低;在叶绿素a(Chla)、藻蓝蛋白(PC)和别藻蓝蛋白(APC)三种光合色素中,藻蓝蛋白(PC)对Ni2+胁迫最为敏感,是Ni2+伤害蓝藻的重要作用位点.Ni2+对M.aerugonisa的抑制作用比Synechocystis sp.更明显.

Effects of Nickel on Growth and Photosynthetic Pigments of Microcystis aeruginosa and Synechocystis sp.

Photosynthesis is significant physiological foundation of growth and propagation for cyanobacterium.Clarifing the response of photosynthetic pigments of blue-green algae to stress conditions can illuminate their injury mechanisms.The present experiments were carried out to reveal the responses of growth and photosynthetic pigments of Microcystis aeruginosa and Synechocystis sp.under different concentrations of nickel stress.The results show that Ni2+ stress(5mg·L-1~25mg·L-1)inhibited the growth of M.aeruginosa after 24h.Although nickel promoted the growth of Synechocystis sp.after being treated for 24h,the growth of Synechocystis sp.was also inhibited after 48h treatment.The light-harvesting capability of the M.aeruginosa and Synechocystis sp.was inhibited obviously after being treated for 24h and 48h respectively.After exposure to different concentrations of nickel,the contents of chlorophyll a in M.aeruginosa and Synechocystis sp.cells decreased significantly.Phycocyanin is mostly sensitive to stress of nickel,which suggested that phycocyanin wound be the target of heavy metals injury to cyanobacterium.