Evidence of biogeography in surface ocean bacterioplankton assemblages

摘要

Regardless of the importance of bacterial assemblages as essential components of ecosystems, little is knownabout how their populations are structured. We analyzed the composition and turnover rates, based on 16SrDNA sequences, of surface water oceanic bacterial assemblages of the fraction between 0.1 and 0.8 pm along alatitudinal gradient (45°6'42"N in the North Atlantic to 15°8'37"S in the South Pacific) including geographicdistance, temperature, chlorophyll a and salinity. Here we show that oceanic bacterial assemblages between0.1 and 0.8 pm, can be structured by a variety of environmental interactions that include separation by distanceand chlorophyll a concentration in temperate North Atlantic coastal samples and temperature in tropicalAtlantic and Pacific coastal and open ocean samples. Bacterial phyla composition diverged between temperateand tropical regions. This study suggests that some bacterial assemblages could be structured both byenvironmental and spatial factors, while others by environmental factors alone.