Immobilization of the white-rot fungus Anthracophyllum discolor to degrade the herbicide atrazine.

C Santos,S Elgueta,M C Diez,N Lima

doi:10.1186/s13568-016-0275-z

Abstract

Herbicides cause environmental concerns because they are toxic and accumulate in the environment, food products and water supplies. There is a need to develop safe, efficient and economical methods to remove them from the environment, often by biodegradation. Atrazine is such herbicide. White-rot fungi have the ability to degrade herbicides of potential utility. This study formulated a novel pelletized support to immobilize the white-rot fungus Anthracophyllum discolor to improve its capability to degrade the atrazine using a biopurification system (BS). Different proportions of sawdust, starch, corn meal and flaxseed were used to generate three pelletized supports (F1, F2 and F3). In addition, immobilization with coated and uncoated pelletized supports (CPS and UPS, respectively) was assessed. UPS-F1 was determined as the most effective system as it provided high level of manganese peroxidase activity and fungal viability. The half-life (t1/2) of atrazine decreased from 14 to 6 days for the control and inoculated samples respectively. Inoculation with immobilized A. discolor produced an increase in the fungal taxa assessed by DGGE and on phenoloxidase activity determined. The treatment improves atrazine degradation and reduces migration to surface and groundwater.

Highlights

Atrazine is the most commonly used herbicide in Chile and perhaps in the world (Mesquini et al 2015) and it is produced by the chemical giant Syngenta as a weedkiller
uncoated pelletized support (UPS)-F1 immobilization was chosen for further evaluations based on its capacity to permit the fungus to growth and produce high levels of manganese peroxidases (MnP)
The results demonstrated that the proliferation of fungal mycelia of A. discolor was significantly higher in the formulation F1

Summary

Introduction

Atrazine is the most commonly used herbicide in Chile and perhaps in the world (Mesquini et al 2015) and it is produced by the chemical giant Syngenta as a weedkiller. It is used for corn, sugarcane and sorghum, and reduces broadleaf and grassy weeds during pre- and postemergence (Cabrera-Orozco et al 2016). Soil contamination by pesticides such as atrazine, during filling of sprayer tanks, can produce severe environmental impacts (Castillo et al 2008; Grigg et al 1997; Lozier et al 2012). WRF produce extracellular ligninolytic enzymes which degrade a wide range of other organic compounds (Rubilar et al 2012). The ligninolytic enzymes from WRF are unique in that they can completely degrade lignin to carbon dioxide and water

Objectives

Methods

Results

Conclusion