By controlling nutrient cycling and biomass production at the base of the food web, interactions between phytoplankton and bacteria represent a fundamental ecological relationship in aquatic environments. Although typically studied over large spatiotemporal scales, emerging evidence indicates that this relationship is often governed by microscale interactions played out within the region immediately surrounding individual phytoplankton cells. This microenvironment, known as the phycosphere, is the planktonic analogue of the rhizosphere in plants. The exchange of metabolites and infochemicals at this interface governs phytoplankton-bacteria relationships, which span mutualism, commensalism, antagonism, parasitism and competition. The importance of the phycosphere has been postulated for four decades, yet only recently have new technological and conceptual frameworks made it possible to start teasing apart the complex nature of this unique microbial habitat. It has subsequently become apparent that the chemical exchanges and ecological interactions between phytoplankton and bacteria are far more sophisticated than previously thought and often require close proximity of the two partners, which is facilitated by bacterial colonization of the phycosphere. It is also becoming increasingly clear that while interactions taking place within the phycosphere occur at the scale of individual microorganisms, they exert an ecosystem-scale influence on fundamental processes including nutrient provision and regeneration, primary production, toxin biosynthesis and biogeochemical cycling. Here we review the fundamental physical, chemical and ecological features of the phycosphere, with the goal of delivering a fresh perspective on the nature and importance of phytoplankton-bacteria interactions in aquatic ecosystems.

中文翻译：

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放大藻圈：浮游植物与细菌之间关系的生态界面。

通过控制食物网底部的养分循环和生物量生产，浮游植物与细菌之间的相互作用代表了水生环境中的基本生态关系。尽管通常在较大的时空尺度上进行研究，但新出现的证据表明这种关系通常受单个浮游植物细胞周围区域内发生的微观相互作用的支配。这种微环境称为“植物圈”，是植物根际的浮游类似物。在此界面上代谢物和信息化学物质的交换控制着浮游植物与细菌之间的关系，这些关系涉及共生，共生，拮抗，寄生和竞争。假设大气层的重要性已经有40年了，但是直到最近才有了新的技术和概念框架，才有可能开始弄清这种独特的微生物栖息地的复杂性。随后变得显而易见的是，浮游植物与细菌之间的化学交换和生态相互作用比以前认为的要复杂得多，并且通常需要两个伙伴的紧密接近，这是由于细菌在藻圈中的定殖而促进的。越来越清楚的是，虽然在藻圈内发生的相互作用是在单个微生物的规模上发生的，但它们对包括养分供应和再生，初级生产，毒素生物合成和生物地球化学循环在内的基本过程产生了生态系统规模的影响。在这里，我们回顾一下基本的身体