Isolation and Identification of Possible Atrazine Degraders from Middle Tennessee Soils

Abstract

Organisms that were potential degraders of atrazine were tested for atrazine tolerance by inoculation onto tryptic soy atrazine agar (TSAA). The atrazine-tolerant organisms were plated onto minimal salts atrazine agar, and compared to growth on minimal salts agar. Six soil samples were taken from various farm land sites in middle Tennessee. Soils had known repeated atrazine use, but had not been sampled for atrazine degraders. Soil isolates were identified using the BBL CrystalTN Identification System. Carbon dioxide (CO2) evolution studies and atrazine enrichment studies were conducted. Six isolates and four known bacteria showed promising 5 day averages of CO2 production, all above 20 of CO2 while in the presence of atrazine. Enrichment procedures showed growth, for 5 out of 6 soil isolates with no glucose and 2.65 mL per 250 mL of medium, indicating their reliance on atrazine for growth. Soil samples taken from middle Tennessee showed organisms with atrazine tolerance and potential atrazine degradation.