Basin-scale variations in labile dissolved phosphoric monoesters and diesters in the central North Pacific Ocean
Basin-scale variations in labile dissolved phosphoric monoesters and diesters in the central North Pacific Ocean
复制标题
北太平洋中部不稳定溶解磷酸单酯和二酯的盆地尺度变化
DOI：
10.1029/2018jc014763
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
and Ken Furuya
中科院分区：
文献类型：
--
作者：
Tamaha Yamaguchi;Mitsuhide Sato;Fuminori Hashihama;Makoto Ehama;Takuhei Shiozaki;Kazutaka Takahashi;and Ken Furuya
在低磷营养的海洋中，易溶的磷酸酯是微生物的重要磷源。尽管不稳定的溶解磷酸酯具有重要的作用，但以往的研究只集中在磷酸单酯上，而包括双酯在内的磷酸酯物种的空间分布和动态仍不清楚。因此，我们的目的是阐明单酯和双酯在盆地范围内的变化及其对微生物的作用，特别是在重氮菌方面。这是首次报道这些磷酸酯在北太平洋中部中低纬度地区的浓度，以及它们的水解率。可水解性单酯和双酯的浓度范围从检测不到的水平到40nM，它们的总和平均占溶解有机磷的11%。虽然单酯浓度在低磷(<；100 NM)区域显著较低，但双酯和磷酸盐浓度之间没有明显的趋势。单酯酶和双酯酶活性在低磷条件下，以叶绿素浓度归一化后，表现出显著的高值。这表明，这两种酯都是包括浮游植物在内的微生物群落的替代磷源。双酯浓度和双酯酶活性与固氮活性呈正相关，而单酯浓度和单酯酶活性与固氮活性无相关性。因此，我们的结果表明，与单酯相比，双酯对重氮菌具有更高的亲和力，单酯被广泛的微生物利用。
Labile dissolved phosphoric esters act as important phosphorus sources for microorganisms in the low‐phosphate oligotrophic ocean. Despite the significant role of labile dissolved phosphoric esters, previous studies have only focused on phosphoric monoesters, and the spatial distribution and dynamics of phosphoric ester species, including diesters, remain unclear. Thus, we aimed to elucidate basin‐scale variations in both monoesters and diesters and their role on microorganisms particularly in terms of diazotrophs. This is the first study to report the concentrations of these phosphoric esters in low‐ to middle‐latitudinal areas of the central North Pacific Ocean, concurrent with their hydrolysis rates. Hydrolysable monoester and diester concentrations ranged from undetectable levels to 40 nM, and their sum accounted for <11% of dissolved organic phosphorus on average. While monoester concentrations were significantly low in the low phosphate (<100 nM) region, there was no obvious trend between diester and phosphate concentrations. Monoesterase and diesterase activities showed significantly high values under low phosphate conditions when normalized by chlorophyllaconcentrations. This indicated that both esters served as alternative phosphorus sources for microbial communities including phytoplankton. Diester concentrations and diesterase activities were positively correlated with nitrogen fixation activities, whereas such relationships were not observed for monoester concentrations and monoesterase activities. Thus, our results suggest that diesters have high affinity to diazotrophs compared with monoesters, which are utilized by a broad spectrum of microorganisms.