Herbicides are extensively employed to suppress weed growth and their applications are considered indispensable for sustaining high agricultural yields [1]. Imidazolinone herbicides constitute a heterogeneous category of agrochemicals and are designed to control weeds by inhibiting the enzyme acetohydroxyacid synthase (AHAS). They have been widely used as selective pre- or post-emergence herbicides on a variety crops, including soybean, alfalfa, wheat, and barley, since the mid-1980s [2, 3]. It has been established that imidazolinone herbicides exhibit long-lasting persistence, resulting in persistent negative impacts on the crop-rotation process and causing soil degradation problems [4]. Consequently, imidazolinone herbicides pose a continuous threat on all living species exposed to it, thereby posing significant ecological and public health concern regarding imazethapyr environment contamination [3, 5,6,7]. In addition to their environmental repercussions, herbicides frequently exert adverse effects on non-target wildlife species, thereby influencing the plant community diversity [8].

Imazethapyr [5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-4, 5-dihydro imidazole-1H-3-yl) nicotinic acid] is a member of the imidazolinone herbicides and is primarily employed for grass and weed control in soybean cultivation, as well as other legumes crops, including barnyard grass, crabgrass, cocklebur, pigweeds, velvetleaf, and others due to its high activity at low application rates and broad spectrum of weed control [1, 9]. Previous studies have shown that imazethapyr exhibits low sorption coefficient and high solubility in water, with a various half-life ranging from 7 to 513 days depending on various factors, such as temperature, soil texture, pH, and microbial activity [10, 11].

These chemical agents block the biosynthesis of amino acids, nucleotides, and lipids or interrupt the process of photosynthesis [12, 13]. Imazethapyr undergoes slow hydrolysis and also displays toxicity toward plants and microorganisms, raising concerns about potential leaching into groundwater and its impact on ecosystem and human health [14,15,16]. Given its toxicity, persistent characteristics, and potential for phytotoxic effects on subsequent crops, it becomes imperative to address its removal.

Several methods, such as physical adsorption, photodegradation, and biodegradation, have been used to treat imazethapyr herbicides in recent years [17,18,19]. These methods play an essential role in the remediation of imazethapyr-contaminated environment. However, concerns have arisen among researchers regarding the toxicity associated with physical adsorption and photodegraded materials, like biochar, TiO2/Ti, which can lead to secondary pollution and induce oxidative stress, inflammation, and autophagy in certain organism [20,21,22]. In response to these concerns, there is a growing emphasis on the development of more efficient and environmentally friendly removal systems. Biodegradation has garnered increasing attention due to its eco-friendliness, high efficiency, low resource consumption, and lack of secondary pollution [18], this approach involves introducing degrading strains into the environment [1, 23, 24]. To date, several imazethapyr-degrading bacterial strains have been identified, including Alcaligenes sp. BH-1, Arthrobacter crystallopoietes WWX-1, Achromobacter, and Pseudomonas sp. IM-4 [23, 25, 26]. Notably, Pseudomonas sp. IM-4 exhibits the highest efficiency for imazethapyr removal, achieving a 73.4% reduction in the initially added 50-mg L−1 imazethapyr concentration after 7 days of inoculation. However, limited information is available regarding the optimal bacterial degradation conditions for imazethapyr. Additionally, the rate of microbial transformation is affected by soil physicochemical properties, and environmental factors [26]. Therefore, it is necessary to optimize the degradation conditions and characteristics to achieve potential maximum degradation ability.

In this study, we isolated bacterial strain IM9601 from agricultural filed soil and conducted an in-depth exploration of its imazethapyr degradation capabilities under diverse conditions, achieving an impressive degradation rate of up to 90%. The primary aim of this study is to optimize the degradation conditions, and evaluate the bioremediation potential of IM9601. The results suggest that IM9601 holds significant promise for the bioremediation of imazethapyr-contaminated environment.