I’m unable to use the greengenes reference tree because I am analyzing the groEL gene rather than the 16S gene. We wanted a deeper analysis of the bifidobacterium genus and go to the species and even strain level that cannot be done using the 16S gene.
As recommended, I tried to use the naive Bayes classifier by running:
Plugin error from feature-classifier:
No matches found
Debug info has been saved to /var/folders/gt/2v1g_2ld469c8hxyxctlt4xc0000gn/T/qiime2-q2cli-err-vpauoyiz.log
Note that the “correct_no_spaces_only_bifido_and_gardnerella_cpn_rep_seqs_upper_no_replicates.qza” is the fasta file of my reference database and the primer sequences are the primers I use to amplify the groEL gene not the indices. So I am unsure of what the error is. Do you know what the issue could be? Thank you!
Then there must simply be no matches for that primer in the reference database that you are using.
You can attempt to spot check a few sequences to confirm, but for what it's worth an NCBI BLAST search using the forward primer does not retrieve any good hits in the nt database.