Figure 1: Bacterial communities were determined by nested PCR-DGGE. Soil samples were from hypersaline sediment (lane 1), lagoons (2-4), garbage collectors from agricultural sectors (5-6), forest with petrified waterfalls and geiser (7-8) and cattle farm (9). Geographic localizations are described in Table 1. The numbers indicate the sequenced amplicons. The amplicons reported in the Gen- Bank appear in italics and underlined. The arrow shows the direction of the urea gradient.