Average values ± the standard deviation of the number of T-RFs and total fluorescence (sum of peak heights) of the T-RF profiles of 38 activated sludge samples after data treatment. *Replicate profiles were normalized and consensus profiles were generated from two replicate profiles only considering T-RFs present in both. **After normalization of consensus profiles. Both replicate and consensus profiles were normalized using the total fluorescence normalization procedure based on peak heights. ***All T-RFs that could not be unambiguously aligned were removed.