School of Life Sciences, and State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.
College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, China; National Marine Hazard Mitigation Service, Beijing, China.
Harmful Algae. 2021 Mar;103:101979. doi: 10.1016/j.hal.2021.101979. Epub 2021 Jan 29.
Prorocentrum obtusidens Schiller (formerly P. donghaiense Lu), a harmful algal species common in the East China Sea (ECS), often thrives with the depletion of phosphate. Three cruises in the spring of 2013 sampled an entire P. obtusidens bloom process to investigate the dynamics of alkaline phosphatase activity (APA) and phosphorus (P) status of the bloom species using both bulk and cell-specific assays. Unlike previous studies, the bloom of P. obtusidens occurred in a phosphate replete environment. Very high APA, with an average of 76.62 ± 90.24 nmol L h, was observed during the early-bloom phase, a value comparable to that in low phosphate environments. The alkaline phosphatase (AP) hydrolytic kinetics also suggested a more efficient AP system with a lower half-saturation constant (K), but higher maximum potential hydrolytic velocity (V) in this period. The APA decreased significantly with an average of 24.98 ± 30.98 nmol L h when the bloom reached its peak. The lack of a correlation between dissolved inorganic phosphate (DIP) or dissolved organic phosphate (DOP) concentration and APA suggested that the APA was regulated by the internal P growth demand, rather than the external P availability during the phosphate replete P. obtusidens bloom. These findings facilitate an understanding of the P. obtusidens acclimation strategy with respect to P variations in terms of AP expression during blooms in the ECS.
钝刺拟菱形藻（曾用名东海原甲藻）是东海常见的有害藻类物种，通常在磷酸盐耗尽时大量繁殖。2013 年春季进行了三次巡航，对整个钝刺拟菱形藻的繁殖过程进行了采样，使用总细胞和细胞特异性测定法研究了碱性磷酸酶活性（APA）和繁殖物种磷（P）状况的动态变化。与以往的研究不同，钝刺拟菱形藻的繁殖发生在富含磷酸盐的环境中。在早期繁殖阶段，观察到非常高的 APA，平均为 76.62 ± 90.24 nmol L h，这一值与低磷酸盐环境中的值相当。碱性磷酸酶（AP）水解动力学也表明，在此期间，AP 系统具有更低的半饱和常数（K），但更高的最大潜在水解速度（V），更为高效。当繁殖达到峰值时，APA 平均下降了 24.98 ± 30.98 nmol L h。APA 与溶解无机磷（DIP）或溶解有机磷（DOP）浓度之间缺乏相关性表明，在富含磷酸盐的钝刺拟菱形藻繁殖期间，APA 受到内部 P 生长需求的调节，而不是外部 P 供应的调节。这些发现有助于了解在东海，AP 表达方面，钝刺拟菱形藻繁殖过程中 P 变化的适应策略。
