SSUextract curated and IMG-enhanced reference databases, version 1.0.0

Versioned SSU rRNA reference databases for SSUextract. The curated profile combines SILVA 138.2 SSURef NR99 for Bacteria and Archaea with PR2 5.1.1 for eukaryotic and organellar host taxonomy. The IMG-enhanced profile uses the same current references and adds IMG 16S and 18S sequences from the 2025 eukcensus dataset. Both profiles include marker-specific BLAST indexes, normalized taxonomy tables, source and build provenance, and license notices. Distributed IMG metadata is restricted to taxon identifiers and valid latitude and longitude values; project, contact, email, and comment fields are excluded.