N‐acyl homoserine lactones (AHLs) are molecules produced by many Gram‐negative bacteria as mediators of cell‐cell signaling in a mechanism known as quorum sensing (QS). QS is widespread in marine bacteria regulating diverse processes, such as virulence or excretion of polymers that mediate biofilm formation. Associated eukaryotes, such as microalgae, respond to these cues as well, leading to an intricate signaling network. To date, only very few studies attempted to measure AHL concentrations in phototrophic microbial communities, which are hot spots for bacteria‐bacteria as well as microalgae‐bacteria interactions. AHL quantification in environmental samples is challenging and requires a robust and reproducible sampling strategy. However, knowing about AHL concentrations opens up multiple perspectives from answering fundamental ecological questions to deriving guidelines for manipulation and control of biofilms. Here, we present a method for sampling and AHL identification and quantification from marine intertidal sediments. The use of contact cores for sediment sampling ensures reproducible sample surface area and volume at each location. Flash‐freezing of the samples with liquid nitrogen prevents enzymatic AHL degradation between sampling and extraction. After solvent extraction, samples were analyzed with an ultra‐high performance liquid chromatography‐high resolution mass spectrometry (UHPLC‐HRMS) method that allows to baseline‐separate 16 different AHLs in less than 10 min. The sensitivity of the method is sufficient for detection and quantification of AHLs in environmental samples of less than 16 cm³.

中文翻译：

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海洋潮间带沉积物中N-酰基高丝氨酸内酯的采样，分离和定量

ñ酰基高丝氨酸内酯（AHL）是由许多革兰氏阴性细菌产生的分子，它们以称为群体感应（QS）的机制作为细胞信号传导的介质。QS广泛存在于调节各种过程的海洋细菌中，例如介导生物膜形成的聚合物的毒性或排泄。相关的真核生物，例如微藻，也对这些线索做出反应，从而形成了复杂的信号网络。迄今为止，只有极少数的研究尝试测量光养性微生物群落中的AHL浓度，而这是细菌-细菌以及微藻-细菌相互作用的热点。环境样品中的AHL定量分析具有挑战性，并且需要可靠且可重复的采样策略。然而，对AHL浓度的了解，从回答基本的生态问题到推导生物膜的处理和控制指南，开辟了多种视角。在这里，我们介绍了一种从海洋潮间带沉积物中取样，AHL识别和定量的方法。使用接触芯进行沉积物采样可确保每个位置的样品表面积和体积均具有可重现性。用液氮对样品进行快速冷冻可防止酶促AHL在采样和提取之间降解。萃取溶剂后，使用超高效液相色谱-高分辨率质谱（UHPLC-HRMS）方法对样品进行分析，该方法可在不到10分钟的时间内对16种不同的AHL进行基线分离。³。