Video talks on 16S data analysis posted.

URMAP ultra-fast read mapper posted (paper).

~20% of taxonomy annotations in SILVA and Greengenes are wrong (paper).

Taxonomy prediction is <50% accurate for 16S V4 sequences (paper).

97% OTU threshold is wrong for species, should be 99% for full-length 16S, 100% V4 (paper).

fastx_relabel command

Re-labels sequences in a FASTA or FASTQ file. By default, the new labels are Seq1, Seq2, Seq3 etc. The prefix can be changed using the -prefix option.

Existing annotations are removed from the labels unless the -keep_annots option is specified.

The output filename is specified by -fastqout (FASTQ format) and / or -fastaout (FASTA format). You cannot create FASTQ output from FASTA input.

Example

usearch -fastx_relabel otus.fa -prefix Otu -fastaout relabeled.fa -keep_annots