Nocardia, a strain of bacteria found within at least one of the samples of each of the atrazine exposed groups, is able to dechlorinate atrazine when found in association with other bacterial strains (Smith et al. 2005). Nocardia has the trzN gene, which encodes for AtzA (atrazine chlorohydrolases), an enzyme that catalyzes the conversion of atrazine into hydroxyatrazine (Udiković-Kolić et al. 2012). These two processes are key to the final degradation of atrazine. Further atrazine breakdown properties have been seen in the bacterial species Ochrobactrum (Udiković-Kolić et al. 2012). When working in consortia with other species, Ochrobactrum breaks down Cyanuric acid, the main substance in atrazine (Udiković-Kolić et al. 2012).
Karim M, Zhao W, Rowley D, Nelson D, Gomez-Chiarri M (2013) Probiotic strains for shellfish aquaculture: protection of eastern oyster, Crassostrea virginica, larvae and juveniles against bacterial challenge. J Shellfish Res 32(2):401–408.  https://doi.org/10.2983/035.032.0220
Udikovic-Kolic N. Scott C.Martin-Laurent F. 2012, Evolution of atrazine-degrading capabilities in the environment, Appl. Microbiol. Biotechnol., 96, 1175–89.