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).

IUPAC codes for sequence wildcard letters

Nucleotide
Symbol Meaning
     A Adenine
     C Cytosine
     G Guanine
     T Thymine
     U Uracil
     M A or C
     R A or G
     W A or T
     S C or G
     Y C or T
     K G or T
     V A or C or G
     H A or C or T
     D A or G or T
     B C or G or T
     X G or A or T or C
     N G or A or T or C

Protein
Symbol Meaning
     X Any amino acid
     B N or D
     Z Q or E

Reference
Cornish-Bowden (1985), IUPAC-IUB symbols for nucleotide nomenclature, Nucl. Acids Res. 13: 3021-3030.