Table 2 Speed of the 4 grouping methods in FastGroupII, and a comparison with FastGroup 1.0. The time in seconds was determined by trimming and grouping the 16S rDNA test dataset found on the FastGroupII website. A total of 621 sequences were dereplicated. A percentage sequence identity of 97% was used to group similar sequences in the PSI, PSI with Gaps and Tree-parsing method. A percentage sequence identity of 83% was used in the Seq-Match method.