Physiological and molecular characterization of active fungi in pesticides contaminated soils for degradation of glyphosate

Abstract

Understanding the physiological and molecular characteristics of naturally occurring fungi in glyphosate pesticide contaminated environment is crucial to managing its contamination. The study was aimed at isolating and characterizing soil fungi for their physiological roles towards glyphosate degradation. Pure cultures of fungi were isolated from soil contaminated with glyphosate at farms in Lagos, Nigeria. The cultures were grown on minimal salt agar media amended with glyphosate. The best isolates exhibiting good tolerance to the glyphosate were characterized using molecular techniques. The BLAST search indicated that the fungi belong to four Aspergillus species (Aspergillus flavus strain JN-YG-3-5, Aspergillus niger strain APBSDSF96, Aspergillus fumigatus strain FJAT-31052 and Aspergillus flavus strain APBSWTPF130, Trichoderma gamsii and Penicillium simplicissimum. The biodegradation study of the glyphosate by the selected fungi species showed the presence of Aminomethylphosphonic Acid (AMPA) except for Aspergillus fumigatus strain FJAT-31052. Annotation analysis of the partial gene sequence shows that the strains possess protein coding gene clusters for glyphosate utilization and other physiological activities. The GhostKOALA output confirmed that CYP2W1 gene (Cytochrome P450, fungi type) was present in Aspergillus fumigatus strain FJAT-31052 which was absent in genome of other fungi. The physiological and molecular characteristics of Aspergillus fumigatus strain FJAT-31052 clearly show that this isolate is a useful organism for managing contamination by glyphosate pesticide.