Biodegradation of Glyphosate by Fungi Species

Abstract. Pesticides are chemicals that combat the attack of various pests on agricultural crops. The use of synthetic pesticides has become an indispensable tool in agriculture. Their use over the years has led to serious environmental pollution. In view of this, efforts have been made by scientists to remove these pollutants from the environment. Degradation of pesticides pollutants by the use of microorganisms has been one of the most environmentally safe and cost effective methods, since these microorganisms exist in abundance in the environment. Glyphosate, an herbicide used for the control of weeds was made to undergo degradation by fungi isolates. The fungi growth was monitored by measuring cell turbidity with a UV-visible spectrophotometer (Genesys IOS VI) at 660nm. The released phosphate ion was determined by spectrophotometric analysis using a UV-Visible spectrophotometer (Genesys IOS VI) at 690nm, using Trichoderma viridae, Aspergillus niger, and Fusarium oxysporum fungi as biodegraders. The release of phosphate ion, was an indication that the first step in glyphosate degradation by fungi is cleavage of the Carbon-Phosphorus bond, resulting in the release of an inorganic phosphate which could be utilized as a source of phosphorus by fungi. There was an inverse relationship between the fungus growth and the amount of phosphate ion in the broth culture over a period o