Fe^(3+)对雨生红球藻(Haematococcus pluvialis)生长及荧光特性的影响

Effects of Fe^(3+) on Growth and Fluorescence Characteristics of Haematococcus pluvialis

为探求适宜雨生红球藻CG-06株生长的Fe3+浓度和Fe3+对藻细胞荧光特性的影响,以BBM为基础培养基,选用EDTA-FeNa(Ⅲ)为Fe3+源,设置0、1.79、8.95、17.9、35.8、71.6μmol.L-16种Fe3+浓度梯度,实验测定藻的生长并分析不同Fe3+对藻细胞叶绿素荧光和77 K低温荧光等的影响。结果表明:适合雨生红球藻CG-06株生长的Fe3+浓度为8.95μmol.L-1,Fe3+浓度较高时,雨生红球藻的生长受到抑制,Fe3+浓度低于1.79μmol.L-1将产生低铁限制。W alz-PAM测定数据显示,在铁不足或高铁抑制条件下,雨生红球藻光系统Ⅱ活性明显下降,开放态的反应中心数目减少,光合作用受到抑制。77 K低温荧光光谱显示,在铁不足或高铁抑制条件下,710 nm荧光峰降低,684 nm和694 nm荧光峰相对增强,说明能量在两个光系统分配上发生变化,能量更多的分配给光系统Ⅱ,限制了光系统Ⅰ的活性。在高铁抑制条件下,CP47蛋白荧光峰降低,CP43蛋白荧光峰增强,推测存在D1蛋白降解。

The optimal range of Fe^3＋ concentration for the growth of Haematococcus pluvialis CG-06 and the influences of Fe^3＋ on the photosynthesis of H. pluvialis were investigated by measuring optical density of algal culture, pigment changes, chlorophyll fluorescence and low temperature fluorescence spectrum. H. pluvialis CG-06 was grown in BBM media in batch culture and six Fe^3＋ concentrations（0,1.79,8.95,17.9, 35.8,71.6 μmol·L^-1）were obtained by adding different amount of EDTA-FeNa（Ⅲ） The results showed that the optimum Fe^3＋ concentration for growth of H. pluvialis CG-06 was 8.95 μmol·L^-1. However, at relatively higher Fe^3＋ concentrations or Fe^3＋ concentration lower than 1.79 μmol·L^-1, algal growth could be inhibited. The data of Walz-PAM showed that the activity of PS Ⅱ was decreased significantly either at Fe^3＋ -deficient condition or Fe^3＋ -excessive condition and the number of open state reaction centers was reduced, resulting in inhibited photosynthesis. At either Fe^3＋ -deficient condition or Fe^3＋ -excessive condition,low temperature fluorescence emission spectrum showed that the peak at 710 nm was reduced while the peaks at 684 nm and 694 nm were enhanced, demonstrating that energy distribution between two photosystems was changed,with more energy being distributed to PS Ⅱ and consequently limi-ting the activity of PSⅠ . Under Fe^3 ＋ -excessive condition, the fluorescence of PS Ⅱ CP47 decreased significantly, but that of PS Ⅱ CP43 increased relatively ,which indicated that D1 protein degradation might exist.