Affiliation:
1. Scripps Institution of Oceanography, Marine Biology Research Division University of California San Diego La Jolla California USA
2. Okinawa Institute of Science and Technology Graduate University Onna Okinawa Japan
3. Kochi Institute for Core Sample Research Japan Agency for Marine‐Earth Science and Technology (JAMSTEC) Nankoku Kochi Japan
4. Atmosphere and Ocean Research Institute The University of Tokyo Kashiwa Chiba Japan
Abstract
AbstractOrganic nanoparticles are abundant in marine environments and constitute important nutrient sources for bacteria. Bacteria have evolved cell surfaces over 3.8 billion years to efficiently utilize food particles, and they contribute to material cycling in the world's oceans. Nanoscale roughness of bacterial cell surfaces reflects outer membrane structures and extracellular polymers that potentially affect cell–particle interactions. However, the variability of surface roughness of marine bacteria has been little studied and its involvement in nanoparticle attachment to bacteria is essentially unknown. Here, for the first time, we show the surface roughness of marine bacteria, evaluated as the root mean square deviation of height (Rq), determined by atomic force microscopy of over 1000 cells of coastal and offshore bacteria in the upper ocean. The Rq varied about 10‐fold among cells (range: 1.0–13.7 nm) and decreased with increasing seawater temperature, implying that bacteria–nanoparticle interactions differ among oceanographic areas. Microcosm experiments using two Gammaproteobacteria (isolated from coastal waters) and modeled with nanoparticle (polystyrene beads and viruses) show that the Rq is a strong predictor of nanoparticle attachment to marine bacteria, that is, bacterial nanoparticle scavenging increases with Rq. This relationship can be explained by steeper peaks/valleys and larger surface area of rougher cells. Measurement of nanoscale surface topography of marine bacteria provides novel insights into bacterial strategies for resource utilization and their contribution to marine biogeochemical cycles.
Funder
Gordon and Betty Moore Foundation
Japan Science and Technology Agency
Japan Society for the Promotion of Science
Subject
Aquatic Science,Oceanography