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).

GG97 database download

GG97 is my name for the default closed-reference database used by QIIME. It is a subset of the Greengenes database (DeSantis et al. 2006) clustered at 97% identity. It is available from the QIIME github repository from the link below.

rep_set/97_otus.fasta.gz

Reference
DeSantis, T.Z. et al., 2006. Greengenes, a chimera-checked 16S rRNA gene database and workbench compatible with ARB. AEM 72(7), pp.5069-72.