Table 1.

Relative levels of bacterial clones related to various phylogenetic groups in clone libraries from aquifer groundwater samples obtained upstream (sample −200b), beneath (sample 0b), and downstream (sample 6b) of the Banisveld landfill

Phylogenetic group% in the following groundwater samples:
−200ba0bb6bc
Low-G+C-content gram-positive group2.937.511.4
High-G+C-content gram-positive group8.612.55.7
α-Proteobacteria5.70.00.0
β-Proteobacteria48.60.020.0
γ-Proteobacteria0.08.30.0
δ-Proteobacteria8.64.225.7
Green nonsulfur bacteria2.94.25.7
Spirochaetales 0.08.30.0
Cytophaga-Flexibacter-Bacteroidesgroup2.90.05.8
Holophaga 0.00.02.9
Verrucomicrobia2.90.00.0
WS5 division0.00.02.9
Unclassified (<90% similarity)16.925.020.0
  • a Principal-component analysis cluster C (Fig. 2); the dominant redox process is denitrification.

  • b Principal-component analysis cluster P2 (Fig.2); the dominant redox process is iron reduction.

  • c Principal-component analysis cluster P1 (Fig.2); the dominant redox process is iron reduction.