Entomology Publications Entomology 1988 Comparative degradation of organophosphorus insecticides in soil: specificity of enhanced microbial degradation Kenneth D. Racke Iowa State University Joel R. Coats Iowa State University, [email protected] Follow this and additional works at: http://lib.dr.iastate.edu/ent_pubs Part of the Entomology Commons, Environmental Health Commons, Environmental Microbiology and Microbial Ecology Commons, Organismal Biological Physiology Commons, and the Plant Sciences Commons The ompc lete bibliographic information for this item can be found at http://lib.dr.iastate.edu/ ent_pubs/390. For information on how to cite this item, please visit http://lib.dr.iastate.edu/ howtocite.html. This Article is brought to you for free and open access by the Entomology at Iowa State University Digital Repository. It has been accepted for inclusion in Entomology Publications by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Comparative degradation of organophosphorus insecticides in soil: specificity of enhanced microbial degradation Abstract Laboratory experiments investigated the comparative degradation of six organophosphorus insecticides in soil as affected by enhanced microbial degradation. The degradation rates and product distributions of chlorpyrifos, fonofos, ethoprop, terbufos, and phorate were not dramatically altered in soils containing microbial populations adapted to rapidly degrade isofenphos. An Arthrobacter sp. isolated from soils with a history of isofenphos use rapidly metabolized isofenphos in pure culture but did not metabolize or cometabolize any of the other five organophosphorus insecticides. Likewise, only fonofos was rapidly degraded in soil with a long history of fonofos use. None of the organophosphorus insecticides were rapidly degraded in soil containing carbofuran-degrading microbial populations. Results indicate that the phenomenon of enhanced microbial degradation of soil insecticides may exhibit some degree of specificity. Disciplines Entomology | Environmental Health | Environmental Microbiology and Microbial Ecology | Organismal Biological Physiology | Plant Sciences Comments Reprinted (adapted) with permission from Journal of Agricultural and Food Chemistry, 36(1); 193-199. Doi: 10.1021/jf00079a049. 1988 American Chemical Society. This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/ent_pubs/390 J. Agric. Food Chem. 1988, 36, 193-199 193 Acid Moiety”.Pestic. Sci. 1985, 16, 46. lation and Residue Analysis of Fenvalerate”. Chromatographia Miyamoto, J.; Mikami, N. “Degradation of Pyrethroid Insecticide 1985, 20, 376. in the Field”. in Pesticide Chemistry: Human Welfare and Quistad, G. B.; Staiger, L. E.; Mulholland, K. M.; Schooley, D. the Environment; Miyamoto, J., Kearney, P. C., Eds.; Perga- A. “Plant Metabolism of Fluvalinate [o-Cyano-3-(phenoxy- mon: Oxford, England, 1983; Vol. 2, p 193. benzyl)-2-[ 2-chloro-4-(trifluoromethyl)anilino]-3-methyl- Ohkawa, H.; Nambu, K.; Inui, H.; Miyamoto, J. “Metabolic Fate butanoate]”. J. Agric. Food. Chem. 1982, 30, 888. of Fenvalerate (Sumicidin”) in Soil and by Soil Reed, W. T.; Ehmann, A.; Lee, P. W.; Barber, G. F.; Bishop, J. Microorganisms”. J. Pestic. Sci. 1978, 3, 129. L. “The Fate and Impact of Pydrina on Nontarget Systems Ohkawa, H.; Kaneko, H.; Tsuji, H.; Miyamaoto, J. “Metabolic Fate following Field Application”. In Pesticide Chemistry: Human of Fenvalerate (Sumicidinm) in Rats”. J. Pestic. Sci. 1979, 4, Welfare and the Environment; Miyamoto, J., Kearney, P. C., 143. Eds; Pergamon: Oxford, England, 1983; Vol. 2, p 213. Ohkawa, H.; Kikuchi, R.; Miyamoto, J. “Bioaccumulation and RUZO,L. 0.;Casida, J. E. “Degradation of Decamethrin in Cotton Biodegradation of the (S)-Acid Isomer of Fenvalerate Plants”. J. Agric. Food Chem. 1979, 27, 572. (Sumicidin”) in an Aquatic Model System”. J. Pestic. Sci. Soderlund, D. M.; Sandborn, J. R.; Lee, P. W. “Metabolism of 1980a, 5, 11. Pyrethrins and Pyrethroids in Insects”. In Progress in Pesticide Ohkawa, H.; Nambu, K.; Miyamoto, J. “Metabolic Fate of Fen- Biochemistry and Toxicology; Huston, D. H., Roberts, T. R., valerate (Sumicidin”) in Bean Plants”. J. Pestic. Sci. 1980b, Eds.; Wiley: Chichester, England, 1983; Vol. 3, p 401. 5, 215. Papadopoulou-Mourkidou,E. “Direct Analysis of Fenvalerate Isomers by Liquid Chromatography. Application to Formu- Received for review March 20, 1987. Accepted August 19, 1987. Comparative Degradation of Organophosphorus Insecticides in Soil: Specificity of Enhanced Microbial Degradation Kenneth D. Racke’ and Joel R. Coats* Laboratory experiments investigated the comparative degradation of six organophosphorus insecticides in soil as affected by enhanced microbial degradation. The degradation rates and product distributions of chlorpyrifos, fonofos, ethoprop, terbufos, and phorate were not dramatically altered in soils containing microbial populations adapted to rapidly degrade isofenphos. An Arthrobacter sp. isolated from soils with a history of isofenphos use rapidly metabolized isofenphos in pure culture but did not metabolize or cometabolize any of the other five organophosphorus insecticides. Likewise, only fonofos was rapidly degraded in soil with a long history of fonofos use. None of the organophosphorus insecticides were rapidly degraded in soil containing carbofuran-degrading microbial populations. Results indicate that the phenomenon of enhanced microbial degradation of soil insecticides may exhibit some degree of specificity. Organophosphorus and carbamate insecticides are et al., 1981))EPTC (Wilson, 1984), and isofenphos (Racke widely used in the Midwest to control such soil-dwelling and Coats, 1987). pests of corn as larval corn rootworms (Diabrotica sp.) and Enhanced degradation is, at its core, a pesticide/microbe cutworms (Agrotis sp.). Corn is now the crop receiving the interaction. The decreased persistence of the pesticide most intensive use of soil-applied insecticides, and in Iowa involved results from rapid catabolism by populations of alone, approximately 6 X lo6 acres are treated annually pesticide-adapted soil microorganisms (Fournier et al., with soil insecticides (Wintersteen and Hartzler, 1987). 1981; Kaufman and Edwards, 1983; Racke and Coats, Although the degradation of individual insecticides in soil 1987). Pesticide catabolism by adapted soil microorgan- has been investigated, few comparative studies of their isms usually involves a hydrolysis, with further metabolism degradation have been conducted (Fuhremann and Li- and utilization of one or more hydrolysis products as chtenstein, 1980). carbon or nutrient sources (Karns et al., 1986; Tam et al., Enhanced microbial degradation is an increasingly im- 1987; Racke and Coats, 1987). portant phenomenon affecting the degradation of pesti- The current research was initiated to study the com- cides in soil (Tollefson, 1986). Enhanced degradation parative degradation of six organophosphorus insecticides occurs when a population of soil microorganisms, which in soil as affected by enhanced microbial degradation. The has adapted due to previous exposure to a pesticide, rap- study focused on determining the specificity of the en- idly degrades a subsequent application of the pesticide. hanced degradative phenomenon, with special emphasis The result of this enhanced degradation is a failure of the on the specificity of enhanced isofenphos degradation. pesticide to adequately control the target pests due to MATERIALS AND METHODS dramatically decreased persistence (Felsot et al., 1982). Enhanced degradation of several commonly used soil Chemicals. The following radiolabeled insecticides, pesticides has been reported, including carbofuran (Felsot along with model metabolites, were obtained from the respective manufacturers: [ U-ring-14C]isofenphos,Mobay Chemical Corp., Kansas City, MO; [2,6-phenyl-14C]- Department of Entomology, Iowa State University, chlorpyrifos, Dow Chemical Co., Midland, MI; [ U-ring- Ames, Iowa 50011. 14C]fonofos,Stauffer Chemical Co., Mountain View, CA; Present address: The Connecticut Agricultural Ex- [I-ethyl-14C]ethoprop, Rhone-Poulenc Inc., Monmouth periment Station, New Haven, CT 06504. Junction, NJ; [rnethylene-14C]terbufosand [rnethylene- 0021-8581/88/1436-0193$01.50/0 0 1988 American Chemical Society 194 J. Agric. Food Chem., Vol. 36, No. 1, 1988 Racke and Coats Table I. Structures and Selected Properties of Organophosphorus Insecticides Studied water soil half-life, compound chemical structure sol: ppm weeks location reference COOCH(CH,), 12 field Chapman and Harris (1982) isofenphos (CH,),CHN 11 22.1 5-8 field Abou-Assaf et al. (1986) )P-0 >14 lab Felsot (1984) 'ZH5' 2-8 field Chapman and Harris (1980a) chlorpyrifos 0.7 2-7 field Pike and Getzin (1981) ,H,,:$ c ,H,,:$ - oQ CI 4-12 lab Getzin (1981) CZHP ci 6 field Kiigemagi and Terriere (1971) fonofos 15.7 6 field Ahmad et al. (1979) 3-5 lab Miles et al. (1979) ethoprop 750 2-12 field Smelt et al. (1977) 14 lab Jordan et al. (1986) 5 <2 field Ahmad et al. (1979) z ti5'\ 11 terbufos ,P-5-CH2-S-C(CH,l, 5.5 2 field Szeto et al. (1986) C2H50 1 lab Chapman et al. (1982b) field Suett (1975) phorate lab Getzin and Chapman (1960) lab Fuhremann and Lichtenstein (1980) aSources: Bowman and Sans, 1979, 1983. Table 11. Soils Used in the Comparative Insecticide Degradation Study texture 70 HzO no. soil serieso insecticide historyb pH OM sand silt clay ('I2bar) I Tama none 7.3 3.9 8.2 58.6 33.2