. 2013 Jun 24;13:146. doi: 10.1186/1471-2180-13-146

Table 2.

Unique and shared richness of microbial communities

	*Bacteria*		*Archaea*
	ATT^a	SUS^b	ATT^a	SUS^b
Total OTUs^c	2,072	1,216	60	266
Normalized OTUs^d	1,243	–	55	–
% OTUs shared	12%	13%	31%	6%
% Sequences in Shared OTUs	37%	31%	90%	22%

^a ATT = Microbial communities attached to in situ samplers.

^b SUS = Microbial communities suspended in groundwater.

^c Operational taxonomic units (OTUs) calculated using a cutoff of 97% average nucleotide similarity.

^d The number of OTUs found in a randomized subset of n sequences where = the number of suspended samples. This was done to account for the greater number of ATT sequences among both bacteria and archaea.