Biodegradation of atrazine using selected marine bacteria: Possibilities for treating pesticide - contaminated wastewater

The use of pesticides including atrazine can cause detrimental problems to the environment. Atrazine, 2chloro-4-(ethylamine)-6- (isopropyl amine)-s-triazine, is one of the widely used herbicides. In this work, thirteen pure bacterial strains were isolated from water and sediments collected from different sites along Alexandria Mediterranean Coast and were evaluated for their efficacy to biodegrade atrazine at three elevated concentrations (I: 109, II: 299 & III: 438 mg/L) for 7 days. Atrazine residues were determined using gas chromatography (GC). Marine isolates exhibited very high atrazine biodegradation with removal efficacy ranging between 15.79 and 75.49, 77.97-97.13 and 27.4-87.6% at three elevated concentrations, respectively. The results indicated that 5 of the isolates (E7, 8, 9,11 and 13) were the most efficient, and active as atrazine bio-degraders. They were affiliated as Bacillus pacificus strain MCCC 1A06182 (E7 and E8), Bacillus cereus strain ATCC 14579 (E9) and Bacillus paramycoides strain MCCC 1A04098 (E11 and E13). Results obtained provided evidence that marine environment is a natural, rich and renewable source of bacteria with marvelous metabolic capabilities for efficient bioremediation of atrazine-contaminated aquatic environments or wastewater. & COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).