Photorespiration in continuous culture of Dunaliella tertiolecta (Chlorophyta): Relationships between serine, glycine, and extracellular glycolate
Photorespiration in continuous culture of Dunaliella tertiolecta (Chlorophyta): Relationships between serine, glycine, and extracellular glycolate
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DOI：
10.1046/j.1529-8817.1998.340651.x
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发表时间：
1998-08-01
影响因子：
2.9
通讯作者：
Jupin, HJ
中科院分区：
文献类型：
--
作者：
Leboulanger, C;Martin-Jezequel, V;Jupin, HJ
在杜氏盐藻（Dunaliella tertiolecta）（屠夫）UTEX LB 999的氮限制连续培养物中监测细胞外乙醇酸盐和细胞内丝氨酸和甘氨酸的游离池的浓度，所述杜氏盐藻在两种不同的辐照度下在光：暗循环中生长。在稳态条件下，这种微生物在轻相期间向培养基中分泌大量乙醇酸盐，高达100 nmol。（10（6）cells）（-1），但乙醇酸盐在黑暗中从溶解相中消失。在70和430 μ mol光子m（-2）·s（-1）下生长的细胞在最大乙醇酸盐浓度、细胞内丝氨酸和甘氨酸浓度以及丝氨酸：甘氨酸比率方面存在差异。这些光子通量密度的抑制导致细胞外乙醇酸盐和细胞内丝氨酸和甘氨酸池的快速修饰。这些结果表明，光呼吸代谢在D。tertiolecta可以通过测量溶解的乙醇酸盐和细胞内丝氨酸和甘氨酸浓度的变化来近似量化，扩展了以前培养的浮游植物的结果，并提出了实地研究的方法。
The concentrations of extracellular glycolate and intracellular free pools of serine and glycine were monitored in nitrogen-limited continuous cultures of Dunaliella tertiolecta (Butcher) UTEX LB999, grown at two different irradiances on a light:dark cycle. Under steady-state conditions, this microalga excreted into the medium a large amount of glycolate during the light phase, up to 100 nmol.(10(6) cells)(-1) for a cell concentration of around 1.5 10(8) cells.L-1, but glycolate disappeared from the dissolved phase in the dark. Cells grown at 70 and those grown at 430 mu mol photons m(-2).s(-1) differed in maximal glycolate concentration, intracellular serine and glycine concentrations, and serine:glycine ratio. Reversal of these photon flux densities to which the cultures were exposed caused rapid modification of the extracellular glycolate and intracellular serine and glycine pools. These results suggest that photorespiratory metabolism in D. tertiolecta could be approximately quantified by measuring the changes in dissolved glycolate and intracellular serine and glycine concentrations, extending previous results from cultured phytoplankton and suggesting methods for field studies.