greengenes2-formatted databases

The biocore group has revived the greengenes database. A description of their approach was published in Nature Biotechnology. If you use these files, you should cite McDonald et al. I have modified the versions made available on the greengenes2 ftp server. The most notable difference is that I removed the species level names since most of the genera only have one species name. In my opinion, this would give an overly specific sense of the classification of your sequences since there is insufficient diversity within each species.