Rapid atrazine mineralization under denitrifying conditions by Pseudomonas sp. strain ADP in aquifer sediments

Atrazine mineralization was studied in sediments taken from a shallow aquifer underlying a cornfield continuously receiving atrazine and terbuthylazine. In contrast to previous publications indicating slow or nonexisting mineralization rates under denitrifying conditions in sediments, we hereby report on the ability of the bacterium Pseudomonas sp. strain ADP to rapidly mineralize atrazine in aquifer sediments under nitrate reducing conditions. When atrazine was present in low concentrations (relevant to nonpoint sources such as agricultural application), the bacterium mineralized 55% and 75% of the atrazine in 2 and 4 days, respectively. When atrazine was present in high concentrations (relevant to spill sites), P. ADP mineralized 48% and 78% in 4 and 15 days, respectively. The present study indicates that bioaugmantation with an effective atrazine mineralizing bacterium such as P. ADP could yield high mineralization rates even under oxygen limited conditions and have a significant implication for bioremediation of atrazine in contaminated aquifers.