Comparative Analysis of Ammonia Oxidizing Bacteria Populations and Ammonia/Nitrate Levels in Diverse Soil Environments.

Ammonia Oxidizing Bacteria (AOB) are critical participants in nitrogen cycling in which they aerobically transform ammonia to nitrite, and then convert nitrite to nitrate.  In this study, the diversity of AOB populations in agricultural, forest and organic soil ecosystems were explored.  Comparative phylogenetic analyses of the soils was performed by cloning and sequencing the active site polypeptide of the ammonia monoxygenase or amoA gene.   If ammonia and nitrate are overabundant, they can contribute to fertilizer loss from agricultural soils, thus causing excessive leaching into groundwater and an overpopulation of bacteria.  Therefore, variations in ammonia and nitrate levels of the soils obtained were also determined. Results confirmed variable differences in the AOB community composition and ammonia/nitrate levels among the three soil environments.  Thus, this study is significant in ascertaining information into the diversity of AOB and the relative ammonia/nitrate levels in soil which can be beneficial to the soil environments’ sustainability and productivity.