ISSN: 2319- 8753 International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 3, Issue 9, September 2014 DOI: 10.15680/IJIRSET.2014.0309071 Copyright to IJIRSET www.ijirset.com 16301 Biodegradation of Imidacloprid, the New Generation Neurotoxic Insecticide Nusarat S Shaikh. 1 *, Snehal V Kulkarni 2 , Mansura S.Mulani 3, ,Ulfat I Baig 4 1*,2,3,4 Abeda Inamdar Senior college for Arts, Department of Science and Commerce, Hidayatullah road, Azam campus, Pune, Maharashtra, India 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 few reports of biodegradation of imidacloprid. Our objectives were to discover, isolate, and characterize microorganisms capable of degrading imidacloprid in soil. Two soil free stable enrichment cultures (NUS1, and NUS4) in minimal media were obtained that showed maximum degradation of Imidacloprid between 48 – 72 hours after incubation. The degradation was indicated by growth of microorganisms in minimal media, where sole source carbon and nitrogen was Imidacloprid. The degradation product was characterized by High Performance Liquid Chromatography (HPLC), which was found to be 6-Chloronicotinic acid. The two isolates were thus found to metabolize Imidacloprid and were further characterized. KEYWORDS: Imidacloprid, insecticide, biodegradation, 6-chloronicotinic acid I. INTRODUCTION Imidacloprid is a systemic chloronicotinyl insecticide, having first been registered in the UK in 1993 and in United States in 1994. It is possibly the most widely used insecticide of the group[3]. It is used to control sucking insects, soil insects, termites and some species of biting insects. It can be used as seed dressing, as soil treatment and foliar treatment in different crops including rice, cotton, cereals, maize, sugar beet, vegetables, etc.[9].Typically application rates range from 0.05-0.125 pounds/acre[4].Imidacloprid field dissipation rates are widely variable, and have been shown to degrade slowly in soil with half-lives exceeding 180 days in non-vegetated soil. Vegetation increased the rate of dissipation of imidacloprid, yielding a range of half-lives from 42-129 days. This effect of vegetation and the identification of a few metabolites may suggest a microbially mediated degradation process that is enhanced through the rhizosphereeffect[7]. Biodegradation of pesticides is controlled by the bioavailability of the pesticide to a pesticide-degrading microorganism and the activity of the microorganism. Bioavailability may limit the biodegradation of imidacloprid and its metabolites in soil, resulting in the long half-lives observed [7]. Expose to Imidacloprid cause symptoms like thyroid lesions, affected reproduction, reduced ability to gain weight, in humans and miscarriages and smaller offspring in pregnant laboratory animals. It is also toxic to birds and cause eggshell thinning. Imidacloprid is responsible for death of shrimp and crustaceans at less than 60ppb concentration [2,15].Considering the toxic effects of Imidacloprid in beneficial insects such as bees, earthworm and also to some degree in humans and its potential to leach groundwater, it is essential to remove these chemo-pollutants from the environment[3].Biological removal of chemo-pollutants becomes the method of choice since microorganisms can use a variety of xenobiotic compounds including pesticides for their growth and they mineralize and detoxify them[12]. Numerous imidacloprid metabolites have been proposed in degradation pathways. Possible microbial metabolites reported in soil metabolism studies include imidacloprid-guanidine, imidacloprid-guanidine-olefin, and imidacloprid-urea[7].Although there are very few reports of imidacloprid-degrading soil microorganisms.Our objectives were to screen, isolate and characterize the microorganisms capable of degrading imidacloprid in soil.