TABLE 3.

Range and averages of percentages of nucleotide divergence in bacterial 16S rRNA sequences within genomes with multiple rrn operonsa

No. of rrn operonsNo. of sequencesRange of divergence (%) (−I/D)Average (%) (−I/D)Range of divergence (%) (+I/D)Average (%) (+I/D)
2b150-1.20.090-1.20.1
370-0.130.0180-0.130.018
4b70-0.070.030-0.070.03
5120-1.230.340-1.360.363
6b100-0.330.1620-0.390.176
7130-1.230.3960-1.360.487
820.910.911.041.04
910.320.320.320.32
1030.97-1.481.150.97-2.181.46
1120.26-0.610.4350.61-0.920.765
1210.330.330.330.33
132NANANANA
151NANANANA
  • a Data were obtained from the NCBI (www.ncbi.nlm.nih.gov/PMGifs/Genomes/micr.html) and TIGR (www.tigr.org/tdb/mdb/mdbcomplete.html) genome databases, the rrndb (http://rrndb.cme.msu.edu) (22), and multiple literature sources. NA, no rrn operon sequences were available.

  • b Four cases of extreme divergence (sequences from microorganisms in which the percentage of nucleotide divergence was much higher than the average) were excluded from the calculation. These were Desulfotomaculum kuznestovii, with two rrn operons and an 8.3% difference, Thermobispora bispora R51 and Thermoanaerobacter tengcongensis, both with four rrn operons and 6.4 and 11.6% differences, respectively, and Thermonospora chromogena, with six rrn operons and 6% divergence.