DCPIP and Respirometry Used in the Understanding of Ametryn Biodegradation

Abstract

In view of an environmental scenario of degradation of the terrestrial ecosystem due to the indiscriminate use of organic compounds, it is necessary to use complementary techniques to evaluate the remediation processes of contaminated soils. Thus, the objective of this work was to evaluate the biodegradation of ametryn herbicide, which is applied in sugarcane crops to control broadleaf weeds. The colorimetric assay was carried out by oxidation of 2.6-dichlorophenol-indophenol (DCPIP) in order to quantify the biodegradation of organic compounds present in the soil, in a short period of time. Another method used was the quantification of CO₂ from the microbial respiration responsible for the metabolization of organic compounds in soil. The biodegradation of the ametryn herbicide was evaluated in soil, with the addition of microbial consortium as bioaumentation and addition of surfactant, as a form of microbial stimulation. It was observed that the addition of bioaumentation and biostimulation favored the increased metabolism of ametryn, reducing its residence time in the environment. The colorimetric assay is simple to perform, bringing rapid results. The respirometric assay is simple to perform, however, it has had long-term results. Thus, the use of a colorimetric assay as the primary evaluation of the biodegradation process of organic compounds and the use of the respirometric assay for the long-term evaluation of the metabolization process is suggested. Therefore, the use of complementary methods helps in understanding the process of biodegradation of organic compounds in the environment, as well as in the combination of factors that favor the mitigation of contaminated sites.