Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America.
Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America.
PLoS One. 2022 Aug 25;17(8):e0272329. doi: 10.1371/journal.pone.0272329. eCollection 2022.
Colloidal particles constitute a substantial fraction of organic matter in the global ocean and an abundant component of the organic matter interacting with bacterial surfaces. Using E. coli ribosomes as model colloidal particles, we applied high-resolution atomic force microscopy to probe bacterial surface interactions with organic colloids to investigate particle attachment and relevant surface features. We observed the formation of ribosome films associating with marine bacteria isolates and natural seawater assemblages, and that bacteria readily utilized the added ribosomes as growth substrate. In exposure experiments ribosomes directly attached onto bacterial surfaces as 40-200 nm clusters and patches of individual particles. We found that certain bacterial cells expressed surface corrugations that range from 50-100 nm in size, and 20 nm deep. Furthermore, our AFM studies revealed surface pits in select bacteria that range between 50-300 nm in width, and 10-50 nm in depth. Our findings suggest novel adaptive strategies of pelagic marine bacteria for colloid capture and utilization as nutrients, as well as storage as nanoscale hotspots of DOM.
胶体颗粒构成了全球海洋中大量有机物的一部分，也是与细菌表面相互作用的有机物的丰富组成部分。我们使用大肠杆菌核糖体作为模型胶体颗粒，应用高分辨率原子力显微镜来探测细菌表面与有机胶体的相互作用，以研究颗粒附着和相关表面特征。我们观察到核糖体膜与海洋细菌分离株和天然海水组合体的形成，并且细菌很容易将添加的核糖体用作生长底物。在暴露实验中，核糖体直接附着在细菌表面上，形成 40-200nm 的簇和单个颗粒的斑块。我们发现某些细菌细胞表现出大小在 50-100nm 之间、深度为 20nm 的表面波纹。此外，我们的 AFM 研究揭示了某些细菌表面的凹坑，其宽度在 50-300nm 之间，深度在 10-50nm 之间。我们的研究结果表明，浮游海洋细菌具有新的适应策略，可用于胶体捕获和利用作为营养物质，以及作为 DOM 的纳米级热点进行储存。
