Adenosine triphosphate (ATP) is the primary energy storage molecule in metabolic pathways. It is common in marine studies to use particulate ATP (PATP) concentrations as representative of microbial biomass. However, there is growing evidence from culture studies, models, and transcriptional data that PATP concentration varies across microbes and conditions, thus compromising interpretations in environmental settings. Importantly, there is a lack of open ocean studies assessing variations in PATP concentrations and thus a deficiency of information on the key biogeochemical drivers for variability in microbial PATP independent of biomass. In sampling the U.S. GO-SHIP P06E zonal transect (32.5° S) across the eastern South Pacific, from the subtropical gyre to the upwelling waters off Chile, we conducted the first comprehensive transect survey quantifying PATP. PATP concentrations increased toward the upwelling region of the transect, but varied vertically when normalized against three measures of biomass: particulate phosphorus, microbial abundance, and microbial biovolume. Generally, greater biomass-normalized PATP concentrations were observed below the deep chlorophyll maximum. Subdividing the P06E transect into four biogeochemical regimes highlighted distinct metabolic strategies used by microbes. Between these regimes, we found PATP concentrations were representative of biomass in upper surface waters. However, below the deep chlorophyll maximum we observed higher biomass normalized PATP concentrations that we hypothesize were due to less availability of energy sources in those subeuphotic zone waters and abundances of chemoautotrophs in the microbial community. This finding suggests that stored energy was more important for these deeper microbes.

中文翻译：

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由于潜在的南太平洋代谢策略，亚亚光微生物中微生物微粒ATP浓度的变化

三磷酸腺苷（ATP）是代谢途径中的主要能量存储分子。在海洋研究中，通常使用微粒ATP（PATP）浓度作为微生物生物量的代表。但是，越来越多的证据来自文化研究，模型和转录数据，表明PATP浓度随微生物和条件的不同而变化，从而损害了环境设置。重要的是，缺乏评估PATP浓度变化的公开海洋研究，因此缺乏有关微生物PATP变异而不依赖生物量的关键生物地球化学驱动因素的信息。在从南亚热带回旋带到智利外的上升水域的整个南太平洋东部采样美国GO-SHIP P06E纬向样条线（32.5°S）时，我们进行了首个量化PATP的综合样带调查。PATP浓度朝着样板上升区增加，但是当针对三种生物量进行归一化处理时，PATP浓度垂直变化：颗粒磷，微生物丰度和微生物生物量。通常，在深叶绿素最大值以下观察到更高的生物量归一化PATP浓度。将P06E样段细分为四个生物地球化学方案，突出显示了微生物所使用的独特代谢策略。在这些制度之间，我们发现PATP浓度代表了上层地表水中的生物量。然而，低于最深的叶绿素最大值，我们观察到较高的生物量归一化PATP浓度，这是我们假设的，这是由于亚共沸带水域中的能源供应较少以及微生物群落中的化学自养菌数量丰富。这一发现表明，对于这些更深的微生物而言，存储的能量更为重要。