ABSTRACT: It is becoming increasingly evident that the use of organic nutrients is widespread among many aquatic phototrophic organisms. Simultaneously, incidents of eutrophication of coastal waters are becoming more common due to rises in organic nutrient loads deriving from anthropogenic activities and natural terrestrial processes. In the northern Adriatic Sea, blooms of the toxic dinoflagellate Ostreopsis cf. ovata are reported as a frequent phenomenon linked to particular environmental conditions, including increased organic nutrient loads. Ostreopsis blooms typically produce a mucilaginous biofilm that can cover all benthic substrata. In order to clarify the role of dissolved organic phosphorus (DOP) in the onset and maintenance of an O. cf. ovata bloom, we investigated the growth rates in the presence of a range of phosphomonoesters (PMEs) (D-fructose 1,6-disphosphate, β-glycerophosphate, α-D-glucose 1-phosphate, guanosine 5’-monophosphate and phytic acid) and phosphodiesters (PDEs) (DNA and RNA). Levels of both phosphomonoesterase (PMEase) and phosphodiesterase (PDEase) activities were assessed in the O. cf. ovata biofilms. The results showed that O. cf. ovata growth is not inhibited in media containing a wide range of DOP and diverse ratios of PME:PDE compared to those containing inorganic phosphorus. Much of the hydrolytic activity was associated with bacteria and with extracellular polymeric substances (EPSs). Our findings suggest that the success of O. cf. ovata stems from the collective participation of all components of the biofilm (O. cf. ovata, EPSs and bacteria) that allows it to thrive in phosphorus-limited environments, but where the main source of phosphorus is organic.

中文翻译：

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Ostreopsis的生长和磷酸酶活性。ovata生物膜提供了多种溶解性有机磷（DOP）化合物

摘要：越来越多的证据表明，在许多水生营养生物中广泛使用有机营养素。同时，由于人为活动和自然陆生过程引起的有机营养物负荷增加，沿海水域富营养化事件也越来越普遍。在亚得里亚海北部，盛开的塔玛的Ostreopsis参见 据报道，卵子是与特定环境条件相关的常见现象，包括增加的有机营养物负荷。骨质疏松花通常会产生粘液性生物膜，可以覆盖所有底栖基质。为了阐明溶解有机磷（DOP）在O的发生和维持中的作用。cf. 卵子绽放，我们研究了在一系列磷酸单酯（PME）（D-果糖1,6-二磷酸，β-甘油磷酸酯，α-D-葡萄糖1-磷酸酯，鸟苷5'-单磷酸酯和植酸）存在下的生长速率）和磷酸二酯（PDE）（DNA和RNA）。O中评估了磷酸单酯酶（PMEase）和磷酸二酯酶（PDEase）活性的水平。cf. 卵形生物膜。结果表明，澳参 卵形与含有无机磷的介质相比，含有多种DOP和不同比例的PME：PDE的介质的生长不受抑制。许多水解活性与细菌和细胞外聚合物（EPS）有关。我们的发现表明O. cf.的成功。卵子源于生物膜所有成分的共同参与（卵子O. cf. ovata，EPS和细菌），使其在磷受限的环境中壮成长，但磷的主要来源是有机物。