is it ok to do taxonomic classification by local alignment search tool (BLAST from NCBI) for OTUs obtained from QIIME2

Hello everyone,
I’m working on taxonomy classification for fungal ITS sequecen. For some reasons, I’d like to use the basic local alignment search tool (BLAST download from NCBI) for the classification, while my OTUs were clustured using open-reference method in QIIME2 (which use the QIIME release database in UNITE). I’m not if there is any problem to do so, because the BLAST tool from NCBI uses a Full “UNITE+INSD” dataset in UNITE and QIIME2 uses a different one.

I’m not very familier with the algorthm and relationship between them and thus worried about the results.
Thank you in advance.


Hi @Fairytale,

You can use either the “QIIME” or “UNITE+INSD” database for your taxonomic classification. The QIIME version is easy to import of course, you can simply follow the instructions to import the respective taxonomy and sequence files as outlined here.

As for the “UNITE+INSD” database… The data might exist as a FASTA file with the taxonomy information in the sequence headers. So, you’ll want to follow the steps outlined below, in order to make a separate taxonomy and sequence file:


More relevant information can be found in the following forum posts:



Hi @SoilRotifer Mike,
Thank you very much for your so detailed reply. I got it. You help a lot.
Many thanks again.



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