PCA of ammonia oxidizing bacterial communities revealed
appreciable diversity at time 0 (Fig. 5), with distinct communities
emerging in the flood/drain and submerged biofilters from treatment
2 onwards. The flood/drain communities formed a tighter
cluster than the submerged communities. The development of this
distinct flood/drain community is illustrated in the T-RFLP data
(Fig. 6) which show that in treatment 3 all flood/drain biofilters
have only two detectable OTUs, a highly abundant 337 bp TRF and
a much less abundant 497 bp fragment. The 497 bp fragment represents
the full length amoA PCR product.