Biodegradation of bifenthrin and fipronil pesticides used in the orange cultivation by bacteria

Abstract

In Brazil, citrus cultivation is of great importance in the country's economy. Only in the 2015/2016 harvest, Brazilian exports of concentrated orange juice totaled 1,080,938 tons. In this context, the use of agricultural pesticides in the orange crop stands out, because in 2016 the agricultural pesticides sector reached US $ 9.56 billion in sales in Brazil. Although pesticides reduce the impact of invasive pests they cause serious environmental problems. Bifenthrin and Fipronil are widely used in agriculture, especially in orange. Bifenthrin is classified as a pyrethroid and is applied as a formicide, presenting little toxicity to humans (acute reference dose of 0.328 mg / kg / day), but to the environment it is a highly toxic product. Fipronil is classified as pyrazole and is a formicide, presenting as low toxicity to man (acute reference dose of 2.0 x 10-4 mg / kg body weight / day), but highly toxic to the environment as well. Therefore, a study covering the biodegradation of these agricultural pesticides is relevant because, in biodegradation, microorganisms such as bacteria, for example, are able to metabolize organic pollutants into products that may not be toxic, bringing benefits both from an agricultural and environmental point of view. This work aims to study the biodegradation of Bifenthrin and Fipronil pesticides used in the cultivation of orange by bacteria. The reactions will be analyzed by High Performance Liquid Chromatography (HPLC) from the monitoring of the chromatographic band for pesticides. Later, if possible, the biodegradation routes of the pesticides under study will be proposed. (AU)