Optimal foraging theory provides a framework to understand how organisms balance the benefits of harvesting resources within a patch with the sum of the metabolic, predation, and missed opportunity costs of foraging. Here, we show that, after accounting for the limited environmental information available to microorganisms, optimal foraging theory and, in particular, patch use theory also applies to the behavior of marine bacteria in particle seascapes. Combining modeling and experiments, we find that the marine bacterium Vibrio ordalii optimizes nutrient uptake by rapidly switching between attached and planktonic lifestyles, departing particles when their nutrient concentration is more than hundredfold higher than background. In accordance with predictions from patch use theory, single-cell tracking reveals that bacteria spend less time on nutrient-poor particles and on particles within environments that are rich or in which the travel time between particles is smaller, indicating that bacteria tune the nutrient concentration at detachment to increase their fitness. A mathematical model shows that the observed behavioral switching between exploitation and dispersal is consistent with foraging optimality under limited information, namely, the ability to assess the harvest rate of nutrients leaking from particles by molecular diffusion. This work demonstrates how fundamental principles in behavioral ecology traditionally applied to animals can hold right down to the scale of microorganisms and highlights the exquisite adaptations of marine bacterial foraging. The present study thus provides a blueprint for a mechanistic understanding of bacterial uptake of dissolved organic matter and bacterial production in the ocean—processes that are fundamental to the global carbon cycle.

最佳觅食理论提供了一个框架，以了解生物体如何平衡补丁中收获资源的收益与新陈代谢，捕食和错失的机会成本之和。在这里，我们表明，在考虑到可用于微生物的有限环境信息之后，最佳觅食理论（尤其是斑块使用理论）也适用于颗粒海景中海洋细菌的行为。结合建模和实验，我们发现海洋细菌Ordalii弧菌通过在依恋和浮游生活方式之间快速切换来优化养分吸收，当养分浓度比背景高一百倍时离开微粒。根据贴剂使用理论的预测，单细胞跟踪显示细菌在营养贫乏的颗粒上以及在环境丰富或颗粒之间的传播时间更短的环境中的颗粒上花费的时间更少，这表明细菌可以调节营养物浓度在分队增加他们的健康。一个数学模型表明，在有限的信息下，即通过分子扩散评估从颗粒泄漏的营养物的收获速率的能力，观察到的在开发和传播之间的行为转换与觅食的最优性相一致。这项工作证明了传统上应用于动物的行为生态学的基本原理如何能够控制微生物的规模，并强调了海洋细菌觅食的精妙适应。因此，本研究为机械理解细菌吸收溶解性有机物和海洋中的细菌提供了一个蓝图，这些过程是全球碳循环的基础。