Figure 3. Phylogenetic positions of nifH from the human faecal metagenomes from six countries, based on deduced amino acid sequences.

A total of 112 amino acid positions were used, corresponding to positions 45–157 of the Klebsiella pneumoniae NifH sequence (AFV52053). Of the four nifH genes from Papua New Guinean individuals, PNG-2 and -4 were not included because they corresponded to positions 138–283 and 124–264, respectively. ‘DSC’ indicates a combined non-redundant gene set of Danish, Spanish, and Chinese populations. See also the legend to Fig. 2.