FIG. 2.

Agarose gel analysis of 16S ribosomal DNA from agricultural and polluted soils amplified with primers CTO (A) and FGPS (B). Lanes 1 through 3, DNA from agricultural soil; lanes 4 through 6, DNA from polluted soil; lane 7, positive control (N. europaea [A] or Nitrobacter winogradskyi [B]). Lanes 1 and 4 contained undiluted soil DNA; lanes 2 and 5 contained soil DNA diluted 1:10; lanes 3 and 6 contained soil DNA diluted 1:100; and lane M contained a 1-kb DNA ladder size standard (Gibco BRL).