Int.J.Curr.Microbiol.App.Sci (2015) 4(5): 632-649 ISSN: 2319-7706 Volume 4 Number 5 (2015) pp. 632-649 http://www.ijcmas.com Review Article A Review on In situ Biodegradation of Methyl Parathion through Soil Microbes Jyoti Sharma* School of Study in Microbiology, Jiwaji University, Gwalior - M.P., India *Corresponding author A B S T R A C T Methyl parathion (O, O-dimethyl O-p- nitrophenyl phosphorothioate,MP) is an K e y w o r d s popular organophosphate insecticides, used extensively and globally for the control of a wide range of insect, pests. Its residues are detected in fruit and Organo- vegetables and classified by the world health organization (WHO) in the class of phosphorus, extremely hazardous pesticides. It inhibits the acetylcholinesterase activity an Methyl important enzyme in the nervous system. Bioremediation is a technique by which parathion, the reduction or elimination of poisonous chemicals from soil, sediment water, or Bioremediation, other contaminated materials is possible with the help of microorganism. Soil is a Soil Bacteria good habitat for microorganisms. Soil microflora is potential candidate for detoxification of pesticides. Soil microbes attack on wide range of organophosphorus insecticides. In this review we focused on rapidly degradation of methyl parathion by soil bacteria at optimized environmental conditions. Introduction Orgnophosphorus pesticides (OP) were first (Mulchandani et al., 1999). OP pesticides developed in Germany by Schrader in 1930 are acutely toxic and act by inhibiting the during World War II in the form of acetylcholine esterase, an important enzyme tetraethyl pyrophosphate as a byproduct of in the nervous system (Kanekar et al., 2004). nerve gas production (Dragun et al., When animals are exposed to OP, this 1984).Various groups of pesticide are used enzyme is unable to function causing the world over, but OP insecticides are most accumulation of acetylcholine, which widely used in agriculture field for interferes with the transmission of nerve protecting the crops which are harmed due impulses at the nerve endings (Synapses). to attack of insects, bacterial, viral, and OP pesticides are mobile in soil. It is fungal pests. OP pesticides also used in hydrophilic in nature and its little amount is homes, garden and in veterinary practices. In absorbed by soil particles. Continuous use of the United States, over 40 million kilograms OP pesticides contaminates different of OP pesticides are applied annually ecosystem of the world (US EPA, 1995; 632 Int.J.Curr.Microbiol.App.Sci (2015) 4(5): 632-649 McConnell et al., 1999; Cisar and Snyder, Ultra-low volume liquid and 2000; Singh and Singh, 2003; Tse et al., microencapsulated product (FAO, 1997; US 2004). It is highly toxic substance to birds EPA, 2003). It is used for control of insects -1 with the LD50 beings 0.9-6.7 mg Kg (IPCS, and mites having chewing and sucking type 1993). Karalliedde et al. (1999) and Sogorb of mouth parts, including thrips, weevils, et al. (2004) has reported that it is causing aphids and leafhopper in a very wide range around 3 millions poisoning with 20, 0000 of crops, including cereals, fruit, nuts, vines, deaths annually. vegetables, ornamentals, cotton, and field crops (Kidd and James, 1991; US EPA, OP insecticides are esters of phosphoric 2003). It kills insects and mites by contact acid, which include aliphatic, phenyl and stomach and respiratory action heterocyclic derivatives and have one of the (Balamurugan et al., 2010). Methyl basic building blocks as a part of their parathion is highly toxic for warm blooded complex chemical structure. Some of the animals the mammals and birds (CICOPLA- main OP insecticides are parathion, methyl FEST, 1997).It is potent inhibitors of parathion, chlorpyriphos, malathion, acetylcholinesterase activity, an important monocrotophos and dimethoate. But in this enzyme in the nervous system. It is applied we are focusing about only methyl parathion to agricultural crops by aerial or ground organophosphorus pesticide. spraying equipment. Methyl parathion has been detected in surface waters and Methyl parathion is an organophosphate sediments, rainwater, aquatic organisms, pesticides used extremely for agriculture cereals and pulses. crop protection (Kumar et al., 1996). It has been banned in many countries because of Methyl parathion can cause death by oral, its higher toxicity for mammals dermal or inhalation exposure and may (Keprasertsup et al., 2001; Sharmila et al., cause deaths. Males may be more 1989). It is highly toxic pesticide with trade susceptible than females to acute effects, name Dimethyl parathion, Mepaton, and children are more susceptible than Mepatox, Methyl E-605 and Methylthophos adults (PAN AP, 2008). Methyl parathion displaying insecticidal activity against a cause different types toxicity, acute toxicity, wide range of insect and arthropod pests sub-chronic toxicity, chronic toxicity, geno- (FAO/UNEP, 1996; US EPA, 2003; toxicity, oncogenicity, reproductive toxicity, Barbalace, 2006; Orme and Kegley, 2006). developmental toxicity, developmental Methyl parathion may also be found in neurotoxicity, immune toxicity and compounds with other insecticides such as hematologic effects (CEPA, 2010). acephate, camphechlor, carbaryl, carbophenothion, cypermethrin, dicofol, Methyl parathion degradation is very slow ethylparathion, ethion, lindane, and takes several months to degrade when methoxychlor, monocrotophos, phosal, applied in soil as a pesticide. When large propargite, petroleum oils, and tetradifon concentration of methyl parathion applied in (Kidd and James, 1991; US EPA, 2003). soil as in an accidental sill, the degradation Methyl parathion is formulated as a number occurs after many years (Howard, 1989). of different commercial products. The most According to many authors (Pritchard et al., commonly available formulations include a 1987; Mathew et al., 1992; Buerger et al., wettable powder (WP), emulsifiable 1994; Reddy et al., 1994; Ortiz et al., 1995) concentrate (EC), dustable powder, and the half life of methyl parathion in natural 633 Int.J.Curr.Microbiol.App.Sci (2015) 4(5): 632-649 water is about one month, which is long Physical and chemical properties of enough to be toxic to many aquatic and methyl parathion (IPCS, 1992) terrestrial organisms. The physical and chemical properties of this Insecticides and their degradation products compound are given below Structure of generally get accumulated in the top soil and MP:- influence not only the population of various groups of ecofriendly soil microbes but also their biochemical activities like nitrification, ammonification, decomposition of organic matter and nitrogen fixation (Agnihotri et al., 1981). *Structure according to California Department of Pesticide Regulation (1999) Molecular formula C8H10NO5S IUPAC name O, O- dimethyl O-4-nitrophenyl phosphorothioate CAS No 298-00-0 Common name Methyl parathion, Parathion methyl, metaphos (World health Organization, 1993) Melting point 35 - 38 ºC Boiling point 143ºC Vapour pressure 1.3m Pa at 20ºC Water solubility 55-60 mg/litre at 25ºC Log octanol- water 1.83-3.43 Partition coefficient Freezing point about 29ºC (technical product) Non aqueous solubility S o l u ble in ethanol, Chloroform, aliphatic solvents and slightly soluble in light petroleum. (World health Organization, 1993) Odour like rotten eggs or garlic (Technical grade) (Midwest Research Institute, 1975; Anon, 1984) Fate of Methyl parathion in environment The distribution of MP in air, water, soil, and organism in the environment is The environment consists of a series of compartments like soil, water, air and other influenced by several physical, chemical and living macro and microorganisms. Once a biological factors (WHO, 1993). Methyl pesticide enters the environment, its parathion is an organophosphate compound, continuous transformation from one which have been used for the control of a component to another occurs. These wide range of insect pests all over the world. processes, in turn, are mediated by several When dispersed in the air, water and soil it significant biological activities which can be becomes pollutant. Pollution caused by both determined by the quantity of residual excessive and continuous use of pesticide. pesticides that persists in anyone These pesticides enter the environment by compartment for a certain period of time. diverse modes such as accidental spills, 634 Int.J.Curr.Microbiol.App.Sci (2015) 4(5): 632-649 direct applications residuals due to facility and soil in environment and less in amount cleaning of containers etc (Ortiz-Hernandez in plant and animal. It also concluded that et al., 2001). Many scientists have studied no movement of MP and its break down the degradation of MP and the concentration product was through soil to ground water. It of its metabolites present in soil sediment, also reported that the concentration of MP air and water. According to Howard (1989), after spraying declined rapidly over 3 days MP takes several months to degrade when and returned to background level after 9 applied in soil but when it is applied in days. WHO (2004) examined in agricultures higher concentration in soil, as in an area of USA and observed that the accidental spill, is degradation takes several concentration of MP in natural water was up years. According to Pritchard et al. (1987), to 0.46 µg/litre but higher level was Buerger et al. (1994) the half life of MP in recorded in summer. natural water is about one month, which is long enough to be toxic to many living WHO (2004) have reported the organisms in the environments. concentrations of MP in food is also present in very small amount, in different regions Stanley et al. (1971) collected the ambient the world. In the USA residues of MP in air sample from both high and low usage food have generally been reported at very seasons. After 12 or 24 hrs they found no low level. Methyl parathion residues were detectable concentration of MP at the site in highest in leaf up to 2 mg/kg and root California near the cities of Fresno and vegetables up to 1 mg/kg reported in the Riverside and detectable concentration as USA.