Biodegradation of imidacloprid by an isolated soil microorganism

Abstract

Imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine), a chloronicotinyl insecticide used to control biting and sucking insects, is very persistent in the soil with a half-life often greater than 100 days. Although a few soil metabolites have been reported in the literature, there are no reports of imidacloprid-degrading soil microorganisms. Our objectives were to discover, isolate, and characterize microorganisms capable of degrading imidacloprid in soil. Two soil-free stable enrichment cultures in N-limited media were obtained that degraded 19 mg L(- 1) (43%) and 11 mg L(- 1) (16%) of the applied imidacloprid, and produced about 19 mg L(- 1) 6-chloronicotinic acid in three weeks. Enrichment media without microorganisms had no loss of imidacloprid. Strain PC-21, obtained from the enrichment cultures, degraded 37% to 58% of 25 mg L(- 1) imidacloprid in tryptic soy broth containing 1 g L(- 1) succinate and D-glucose at 27 degrees C incubation over a period of three weeks. Trace amounts of NO(3)(-)/NO(2)(-)were produced and six metabolites were characterized by high performance liquid chromatography (HPLC) using (14)C-methylene-imidacloprid and liquid chromatograph-electrospray-mass spectrometer (LC-MS). Two of the metabolites were identified as imidacloprid-guanidine and imidacloprid-urea by HPLC standards and LC-MS. During the experiment, 6-chloronicotinic acid was not produced. Less than 1% of the applied (14)C was incorporated into the microbial biomass and no (14)CO(2) was detected. Strain PC-21, identified as a species of Leifsonia by PCR amplification of a 500 bp sequence of 16s rRNA, cometabolized imidacloprid.

PesticideLambda-Cyhalothrin DegradationUsingMesorhizobium sp.(S1b) andBartonella sp.(S2b)StrainsIsolated from Cotton Crop

“…In this case LC was used as representatives of pyrethroid pesticides (sole source of carbon and energy) during ex-situ biodegradation studies. It is believed that one gram of soil have approximately more than one hundred million bacteria and 5000-7000 different bacterial strains [31]. The different microbes have been isolated from polluted soils having ability to degrade pesticides [32][33].…”

Potential of Enterobacter sp. Strain ATA1 on imidacloprid degradation in soil microcosm: Effects of various parameters

“…Specifically guanidine and urea metabolites were recovered from metabolism of imidacloprid (37-58% of 25 mg L 21 over 4 weeks) by the Leifsonia sp. strain PC-21 [11]. Apart from I-1 and I-5, others (I-2, I-3, I-4, and I-6) are also characterized in this study.…”

Caracterización de cepas nativas de suelos agrícolas tolerantes a imidacloprid

“…Diversas especies microbianas de suelo han sido aisladas usando como única fuente de carbono y energía a insecticidas químicos. Se ha reportado a Klebsiella pneumoniae, Pseudomonas sp., Stenotrophomonas maltophilia, Pseudoxanthomonas indica (Liu et al, 2013;Ma et al, 2014), Leifsonia (Anhalt et al, 2007), Brevibacterium sp., Pseudomonas putida, Bacillus sp. Rhizobium sp.…”