摘要
The enzyme-labeled fluorescence (ELF-97®) substrate produces an insoluble, fluorescent yellow-green product at the site of alkaline-phosphatase (AP) activity. Fifteen coastal phytoplankton species were tested to determine if AP activity could be detected in phosphate-depleted media. All species tested, except Synechococcus bacillaris, expressed AP activity. Subsequently, threshold concentrations of soluble reactive phosphate (SRP) at which AP activity could be detected by ELF-97® were determined for Chaetoceros neogracile, Chlorella autotrophica, Isochrysis sp., Prorocentrum minimum, and Tetraselmis chui. Microalgal species differed significantly in the SRP concentration at which AP activity was first detectable (10.1–16.4 μM), well above concentrations normally considered limiting for phytoplankton. P. minimum began to express AP activity at a higher SRP concentration than the other algal species; this may be attributable to a relatively high DNA/cell ratio in P. minimum, compared to the other phytoplankton. Thus, phytoplankton species may respond to phosphorus deficiency at high SRP concentrations.
摘要译文
酶标记荧光（ELF-97）底物在碱性磷酸酶（AP）活性位点产生不溶性的荧光黄绿产物。测试了十五个沿海浮游植物物种，以确定在磷酸盐贫乏的培养基中是否可以检测到AP活性。除聚球藻外，所有测试的物种都表达了AP活性。随后，测定了通过ELF-97检测AP活性的可溶性反应性磷酸盐（SRP）的阈浓度，用于Chaetoceros neogracile，小球藻属，等鞭毛藻，Prorocentrum最小值和Tetraselmis chui。首先检测AP活性的SRP浓度中微藻种类差异显着（10.1-16.4μM），远远高于通常被认为限制浮游植物的浓度。 P.最小值开始以比其他藻类物种更高的SRP浓度表达AP活性;这可能归因于与其他浮游植物相比，P.最小值的DNA /细胞比例相对较高。从而，浮游植物物种可能在高SRP浓度下对磷缺乏作出反应。
Shannon L. Meseck [1] Jennifer H. Alix [1] Gary H. Wikfors [1] J. Evan Ward [2]. Differences in the Soluble, Residual Phosphate Concentrations at Which Coastal Phytoplankton Species Up-regulate Alkaline-Phosphatase Expression, as Measured By Flow-Cytometric Detection of ELF-97® Fluorescence[J]. Estuaries and Coasts, 2009,32(6): 1195-1204