Metabolism of Atrazine in Liquid Cultures and Soil Microcosms by Nocardioides Strains Isolated from a Contaminated Nigerian Agricultural Soil
Date
2013-05-01
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor & Francis Group
Abstract
Atrazine-degrading microorganisms designated EAA-3 and EAA-4, belonging to the genus
Nocardioides, were obtained from an agricultural soil in Nigeria. The degradation kinetics of the two
strains revealed total disappearance of 25 mg l-1 of atrazine in less than 72 h of incubation at the rate
of 0.42 mg l-1 h-1 and 0.35 mg l-1 h-1, respectively. Screening for atrazine catabolic genes in these
organisms revealed the presence of trzN, atzB, and atzC. Other genes, specifically atzD, were not
detected. Potential intermediates of atrazine catabolic route such as hydroxyatrazine, desethylatrazine,
and desisopropylatrazine, and desisopropylatrazine were utilized as sources of carbon and energy,
while desisoprophl desethyl-2-hydroxyatrazine and desisopropyl-2-hydroxyatrazine were attacked but
in the presence of glucose. A soil microcosm study showed that degradation was faster in
microcosms contaminated with 13 mg of atrazine per g-1 of soil compared with 480 mg g-1 of soil. In
the former, degradation was 10% higher in the inoculated soil than the non-inoculated control (natural
attenuation) over the 28-day study period. Corresponding value obtained for the latter was nearly 70
% higher. This study has demonstrated that the bacterial strains isolated enhanced atrazine
degradation and the catabolic activities of these strains were not affected with increasing soil atrazine
concentration.
Description
Keywords
Agricultural soils, Atrazine, Carbon, Energy, Genes, Glucose, Metabolism, Microorganisms, Screening
Citation
Omotayo, A. E., Ilori, M. O., Radosevich, M., & Amund, O. O. (2013). Metabolism of atrazine in liquid cultures and soil microcosms by Nocardioides strains isolated from a contaminated Nigerian agricultural soil. Soil and Sediment Contamination: An International Journal, 22(4), 365-375.