TABLE 1.

Comparison of various techniques to determine the frequency distribution and richness estimates for 16S rRNA gene collections from Scottish and Amazonian soilsa

Source of 16S rRNA gene libraryAnalysis methodTotal no. of se- quencesNo. of unique OTUsNo. of OTUs with nx sequencesb
n1n2n3n4n5n6
Scottish soilMcCaig13711498122110
Hughes13711396132110
FastGroup13713112730100
NN13711296122011
AN13711397122020
FN13711498122110
Amazonian soilFN98847561200
  • a OTUs were defined by using a distance level of 3%. The frequency distribution of the improved Scottish soil 16S rRNA gene library of McCaig et al. (21) was determined from rank abundance data from McCaig et al. (21) and Hughes et al. (14), from output of the FastGroup program of Seguritan and Rowher (26), and by using the three assignment algorithms implemented in DOTUR. For comparison, the Amazonian soil library (2) was analyzed by using the furthest neighbor algorithm in DOTUR. NN, nearest neighbor assignment algorithm; AN, average neighbor assignment algorithm; FN, furthest neighbor assignment algorithm.

  • b n1, no. of singletons; n2, no. of doubletons; etc.