Table 2.

Total number of operational taxonomic units (OTUs) clustered at three similarity thresholds showing the number of OTUs retained after each filtering step during data processing, and used in each of the nine analyzed data sets.

	Clustering threshold
Factor	90%	95%	97%
Total OTUs	5975	46,066	102,255
Passed BLAST vs MaarjAM	399	2857	7288
Passed UCHIME	395	2836	7279
Passed BLAST vs NCBI nt	385	2795	7255
No. OTUs in all OTUs data set	365	2524	6416
No. OTUs in ≥2-ton data set	276	1250	2213
No. OTUs in ≥10-ton data set	196	374	407

Note: NCBI nt = National Center for Biotechnology Information nonredundant nucleotide database; OTU = operational taxonomic unit.