Hi,
I got the latest version of PICRUST2 .
I went into look at the EC and KO datafiles for the PICRUST
It seems that the KOs for dissimilatory sulphate reduction (according to KEGG) : K00958 (K00394+K00395) (K11180+K11181-K27196) (K27187+K27188+K27189+K27190+K27191)
https://www.genome.jp/module/M00596+K00958
are missing from the KEGG PICRUST table.
Also, the EC number corresponding to the dissimilatory sulphate reductase EC 18.99.1 is also not contained in the EC table.
It seems that the PICRUST2 table is incomplete.