Isolation and identification of glufosinate ammonium-tolerant bacteria from agricultural soil samples

Abstract The excessive use of glufosinate ammonium (GA) in agriculture contributes to soil degradation, microbial imbalance, and potential health risks due to environmental contamination. In this study, we isolated and identified GA-tolerant bacterial strains from agricultural soils in Hong Van commune, Hanoi city, Vietnam, an area with frequent herbicide application. Four bacterial strains, designated TN1 - TN4, were able to grow on nutrient agar containing 900 ppm GA. Among them, strain TN2 maintained comparable growth in both GA-containing and GA-free media, which indicates a high level of tolerance. Morphological observation and biochemical tests revealed that TN2 was a short, rod-shaped, Gram-negative bacterium capable of utilizing citrate and producing catalase and urease. To our interest, 16S rRNA gene sequencing identified TN2 as Bordetella bronchiseptica , a species commonly associated with animals but occasionally found in polluted environments. Our study suggests that the presence of catalase, urease, and citrate utilization pathways may contribute to its ability to survive under herbicide stress. Taken together, these findings provide preliminary insights into microbial tolerance mechanisms under prolonged herbicide exposure, which may inform future studies on bioremediation strategies.