Isolation and Characterization of Glyphosate–Degrading Bacteria from Agricultural Soil in Awka, Anambra State, Nigeria

Abstract

Glyphosate is a very effective pesticide; hence it has been excessively used in agricultural activities. This led to glyphosate residue accumulation in the soil and resulted in various adverse effects on humans and the ecosystem. This necessitates the need to reduce glyphosate accumulation in the soil and microbial bioremediation can be the solution. Thus, this study aimed to isolate and characterize glyphosate degrading bacteria from agricultural soils exposed to glyphosate weed control method. Bacterial organisms were isolated from glyphosate polluted agricultural soil and were characterized using routine microbiological biochemical methods. The isolates were screened for glyphosate utilization using a mineral salt medium containing glyphosate as a carbon source. Confirmed glyphosate degraders were identified using 16s rDNA sequencing. These isolates were assessed for their ability to degrade 106.16 µg/ml glyphosate in varied volumes (1 ml, 1.5 ml and 2 ml), singly and in consortium. Glyphosate degraders were identified as Exiguobacterium alkaliphiluim, Alcaligenes faecalis, Sinorhizobuim fredii and Acinetobacter nosocomialis. These organisms significantly (p<0.05) degraded different glyphosate volumes as a consortium more than as individual organisms. This study has been able to show the different glyphosate degraders present in some glyphosate-polluted agricultural soils in Awka, Anambra State, Nigeria.