Diverse diazotrophs on sinking marine particles. marine metagenome

Sinking particles transport carbon and nutrients from the surface ocean into the deep sea and are considered hot spots for bacterial diversity and activity. In the oligotrophic oceans, nitrogen (N2)-fixing organisms are an important source of new N but the extent to which these organisms are present and exported on sinking particles is not well known. Sinking particles were collected using net traps deployed at 150 m in the North Pacific Subtropical Gyre, observed and picked using a dissection microscope. The associated community was assessed using 16S rRNA gene amplicon sequencing. N2-fixers were identified by sequencing of the nifH gene, encoding a subunit of the nitrogenase enzyme.