Biodegradation of Herbicide Propanil and Its Subproduct 3,4-Dichloroaniline in Water

• Published in: Clean : soil, air, water Vol. 40; no. 9; pp. 958 - 964
• Main Authors: Roehrs, Rafael, Roehrs, Miguel, Machado, Sérgio L. de O., Zanella, Renato
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.09.2012; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Bioremediation; Enterobacter cloacae; Environmental pollution; Enzyme activity; Herbicides; Microorganism; Pesticide; Pesticides
• ISSN: 1863-0650; 1863-0669
• DOI: 10.1002/clen.201100693

The rational use of pesticides generates an impact which is normally reversed and eliminated by the environment itself. However, the indiscriminate use of pesticides makes its natural degradation rhythm difficult, prolonging their presence in the soil for a great deal of time. Aiming towards a decrease in the environmental impact of pesticides, soil microorganisms capable of degrading pesticides, such as propanil, were investigated. An Enterobacter cloacae strain, isolated from rice field soil, was exposed to the herbicide propanil alone and in a mixture containing also bentazone, clomazone, quinclorac, and 2,4‐D. This bacterium was able to eliminate 100% of the applied propanil in 28 days. Propanil degradation in the 5‐herbicide mixture was much lower than that of individual pesticide degradation. The aeration of the system helped to degrade propanil and its subproduct 3,4‐dichloroaniline much faster. LC with UV detection was used to determine the remaining concentrations of the herbicides and their subproducts. In a mixture, propanil and 3,4‐DCA can be degraded faster by the bacteria strain RR02 using aeration at 30 and 37°C. The use of E. cloacae in bioremediation of pesticides could be very useful because 3,4‐DCA is not a specific subproduct of propanil, but also of some phenylureas and carbamates. E. cloacae is found naturally in soil and therefore can be used in water at real conditions.