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).

FASTA files

The FASTA sequence file format is widely supported by bioinformatics tools. For a detailed description, see this Wikipedia entry about FASTA.

USEARCH allows lines of any length in a FASTA file. (Some programs limit lines to e.g. 80 characters).

USEARCH does not support comments in FASTA files.

White space characters (blanks and tabs) are discarded if found in sequence data, but many other tools do not allow this and the practice is not recommended.

If the -trunclabels option is given, USEARCH will truncate sequence labels at the first white space (similar to BLAST), otherwise the full label is retained..