Performance evaluation of Trichoderma reseei in tolerance and biodegradation of diuron herbicide in agar plate, liquid culture and solid-state fermentation

Abstract

Abstract The present work evaluated the performance of the fungus Trichoderma reesei to tolerate and biodegrade the herbicide diuron in its agrochemical presentation in agar plate, liquid culture, and solid-state fermentation. The tolerance to diuron was characterized through a non-competitive inhibition model, showing higher tolerance on the PDA agar plate (Ki=98.63 mg L− 1) than liquid culture with glucose and ammonium nitrate as carbon and nitrogen sources (Ki=39.4 mg L− 1). Diuron biodegradation was characterized through the model of inhibition by the substrate. Trichoderma reesei had a maximum radial growth rate (vrmax) of 1.17 cm d− 1 on agar plate. In liquid culture, Trichoderma reesei biotransformed diuron in 3,4-dichloroaniline using the amide group from the diuron structure as a carbon and nitrogen source, with a maximum specific growth rate (µmax) of 0.0245 h− 1 and a yield of the biomass on the substrate (YXD) of 0.154 mg mg− 1. In solid-state fermentation with a mix of barley straw and agrolite (70:30) as support-substrate, the maximum diuron removal percentage (97.26%) was reached with a specific aeration rate of 1.0 vkgm, inoculum of 2.6x108 spores g− 1, and an initial diuron concentration of 160.81 mg kg− 1. The diuron removal in solid-state fermentation by sorption on the barley straw and agrolite was discarded compared with the removal magnitude of the biosorption and biodegradation mechanisms of Trichoderma reesei. The Trichoderma reesei performance in its tolerance and capability to remove diuron in liquid and solid culture media displays its potential to be used in bioremediation technologies of herbicides polluted sites.