3.6. Bacterial Diversity and Its Role with Arsenic Release and Phosphorus Fertilizers. Bacterial diversity from sediments in sampling site ASYL718 was further examined. Proteobacteria appear to be the only bacteria in all microcosms (Figure 5). Proteobacteria have also been found in bacterial communities in soils contaminated with heavy metals or arsenic.57−61 α-Proteobacteria were found to be the most prominent group in both original sediments (73%) and sediment after 4 months of incubation (59%) (Figure 5). α-Proteobacteria were also found in the sediment (>20%) located adjacent to this study sampling site,27 yet the microbial populations within α-proteobacteria were different between the two sampling sites.