Undervalued Pseudo- <i>nifH</i> Sequences in Public Databases Distort Metagenomic Insights into Biological Nitrogen Fixers

Abstract

Nitrogen-fixing microbes affect biogeochemical cycling, agricultural productivity, and microbial ecosystems, and their distributions have been investigated intensively using genomic and metagenomic sequencing. Currently, insights into nitrogen fixers in the environment have been acquired by homology searches against nitrogenase genes, particularly the nifH gene, in public databases.