I have got my feature table using the dada2 algorithm, then I exported and merged it with the taxonomy annotation file obtained from sliva_128 release. The out_id in the OTUID column looks something like “01fe2ad4c2e075979225a4966bb8137a”. How can I convert it into genbank accession number(eg: “EU722746.1”) so that i can search the database.
The QIIME2 website contains links to various compatible databases. You could download a set of genbank sequences, reformat to match those compatible references, and use that custom database for searching.
Alternatively, if you are interested in searching for specific sequences against genbank, use qiime feature-table tabulate-seqs as shown here. The output provides streamlines searching genbank for individual records if you really want to pick through (use feature-classifier against a custom database if you want to classify all sequences to taxonomy)