The diversity of Planctomycetes and related bacteria in 3 types of freshwater wetlands with different anthropogenic
disturbances were investigated by cloning and sequencing PCR-amplified partial 16S rRNA genes. Three
clone libraries were constructed using 16S rRNA-targeted forward PCR primer specific for Planctomycetales and
general bacterial reverse primer. Phylogenetic analysis of the 16S rRNA gene sequences defined 95 operational taxonomic
units (OTUs) with 163 sequences. The clone libraries covered a wide microbial diversity of Proteobacteria and
the Planctomycetes-Verrucomicrobia-Chlamydiales (PVC) superphylum. The majority of the OTUs were related to
the phylum of Planctomycetes (33 OTUs), Proteobacteria (22 OTUs) and Verrucomicrobia (22 OTUs). Four known
genera from the Planctomycetes phylum were all detected. The genus Pirellula (18 OTUs) dominated the Planctomycetes
community, but different patterns of distribution were observed in the wetlands. The littoral wetlands of Baiyangdian
Lake with the least anthropogenic disturbances covered more species and showed the highest biodiversity.
However, the Jiaxing paddy fields with the highest anthropogenic disturbances showed a higher biodiversity than
that in the riparian wetlands of the North Canal. Bacteria distantly related to anammox bacteria were also detected
with a small proportion (4 OTUs). It showed that wetlands hold a great biodiversity of phyla Planctomycetes and related
bacteria; furthermore, there is ample opportunity to discover novel phylotypes of Planctomycetes in the wetland
ecosystems.