Identification, enumeration and diversity of nitrifying planktonic archaea and bacteria in trophic end members of the Laurentian Great Lakes

摘要: Oligotrophic Lake Superior and mesotrophic Erie are trophic end members of the hydrologically connected Laurentian Great Lakes system, as such exhibit different profiles dissolved nitrogen species. Nitrification in has led to increasing nitrate concentrations over past century, opposed Erie, where inventories have declined due denitrification. In this study, we examined abundance diversity nitrifying microbes involved oxidation ammonia nitrite, nitrite nitrate. By situ hybridization methods, enumerated major planktonic oxidizing bacteria (AOB) archaea (AOA) during a July 2011 cruise from Erie. Superior, AOA dominated compared AOB, typically exceeding 5 × 103 mL− 1, whereas AOB were more abundant than AOA. These data parallel prior work on sediments, which far but dominate The lakes sampled stratification, largely restricted hypolimnion, consistent with observation that oxidizers photoinhibited surface waters. also detected (NOB) pattern paralleling AOA/AOB abundance. Phylogenetic analysis archaeal 16S rRNA revealed Group I.1a Thaumarchaeota most closely related Nitrosoarchaeum limnia. distinct sediments. form subcluster within genus Nitrosospira.