Combined microbiological test to assess changes in an organic matrix used to avoid agricultural soil contamination, exposed to an insecticide

Abstract

Combined microbiological test (Biolog Ecoplate, denaturing gradient gel electrophoresis (DGGE) and Real Time PCR (qPCR)) were developed to evaluate the impact of repeated diazinon (DZN) applications at high concentration (40 mg kg-1) on microbial communities in a microcosm simulating the organic matrix (straw (50%): peat (25%): soil (25%) vv-1) of an pesticide biopurification system (PBS). Moreover, pesticide dissipation was also evaluated. After three successive exposition of DZN, dissipation efficiency was high; achieved 87%, 93% and 96% after each application, respectively showing a clear accelerated dissipation of this pesticide in the organic matrix. The results obtained with Biolog Ecoplate showed that community level physiological profiles were no affected by the addition of DZN. On the other hand, molecular assays (DGGE and QPCR) demonstrated that the microbial structure (bacteria and fungi) remained relatively stable over time with high DZN doses compared to control. Therefore, the results of the present study, clearly, demonstrate the high dissipation capacity of this biomixture and highlight the microbiological robustness of this biological system.Fil: Tortella, G. R.. Universidad de la Frontera. Nucleo Cientifico y Tecnologico En Recursos Naturales (bioren-ufro). Departamento de Ciencias Quimicas y Recursos Naturales; ChileFil: Salgado, E.. Universidad de la Frontera. Nucleo Cientifico y Tecnológico En Recursos Naturales; ChileFil: Cuozzo, Sergio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); ArgentinaFil: Mella Herrera, R. A.. Universidad de la Frontera. Nucleo Cientifico y Tecnológico En Recursos Naturales; ChileFil: Parra, L.. Universidad de la Frontera. Núcleo Científico y Tecnológico en Recursos Naturales; ChileFil: Diez, M. C.. Universidad de la Frontera. Nucleo Cientifico y Tecnológico En Recursos Naturales; ChileFil: Rubilar, O.. Universidad de la Frontera. Nucleo Cientifico y Tecnológico En Recursos Naturales; Chil

Enhanced Dissipation of Selected Herbicides in a Simulated Organic Matrix Biobed: A System to Control On‐Farm Point‐Source Pollution

“…In this study, phenol oxidase activity after day 10 was significantly higher than at time zero. The highest phenol oxidase activity was observed at 30 d. Tortella et al (2013aTortella et al ( , 2013bTortella et al ( , 2014 reported that the concentrated pesticides initially had an inhibiting effect on enzyme activity and that enzyme activity recovered after pesticide dissipation. Tian and Shi (2014) reported that, several weeks after adding plant litter to soil, the enzyme activities (e.g., b-glucosidase, b-glucosaminidase, exoglucanase, and phenol oxidase) increased rapidly to a peak; however, exoglucanase and phenol oxidase activities were dependent on litter quality.…”

“…Using individual, volatile, organic compounds, such as terpenes, at a low concentration significantly enhanced atrazine degradation and biological activity (Tortella et al, 2013c). Repeated, concentrated pesticide applications on microbial communities in a simulated biobed matrix demonstrated that the organic matrix system presented a high dissipation capacity, in addition to being microbiologically robust (Tortella et al, 2013a, 2013b, 2014).…”

Pesticide dissipation capacity of an organic biomixture used in the agriculture exposed to copper oxychloride

“…Other chemicals reagents were of analytical reagent grade and purchased from Merck S.A. (Chile). ATZ, DZN and CARB were selected based on their normal use in agriculture, contrasting solubility and because they have been effectively dissipated in the biomixture (Tortella et al, 2013a, b;Tortella et al, 2014).…”

“…All assays were established in triplicate. Controls with single pesticides were not run, because their dissipation and individual effects on the microbiological properties of the biomixture have been previously reported (Tortella et al, 2013a, b;Tortella et al, 2014). Additionally, a control with sterilized biomixture was carried out to evaluate the abiotic dissipation of pesticides.…”

“…In OBS, the organic biomixture is the main component and responsible for the high biological activity and consequently for an efficient pesticide dissipation; the biomixture is composed by agricultural soil, peat and wheat straw (25:25:50% by volume) (Castillo et al, 2008). Several works have demonstrated that the biomixture is able to dissipate several types of pesticide (alone or mixtures) and at high concentrations (Tortella et al, 2012;Tortella et al, 2013a, b;Marinozzi et al, 2013;Tortella et al, 2014;Chin-Pampillo et al, 2015;Holmsgaard et al, 2017;Diez et al, 2017;Diez et al, 2018).…”