Estimation of species coverage and diversity were carried out for the two 16S rDNA clone libraries. Good coverage was found in both libraries (70.8% for R1 and 70.6% for R2). Sequences analysis showed that 36 distinct OTUs and 34 distinct OTUs were obtained from the bioaugmented sludge and the control sludge clone libraries, respectively. It was important that a significant number of the OTUs comprised of a single clone, indicating high levels of bacterial diversity. Shannon-Weaver indices were observed to be 4.23 in R1 and 4.25 in R2. This high similarity suggested that bioaugmentation did not result in the transformation of community diversity.