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 showed 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 the genome of other fungi. The physiological and molecular characteristics of Aspergillus fumigatus strain FJAT-31052 clearly show that this fungus is a useful organism for managing contamination by glyphosate pesticide.

Glyphosate Pollution Treatment and Microbial Degradation Alternatives, a Review

“…Kulikova et al (2020) [169] report that the biodegradation of the herbicide can be carried out both with the formation of AMPA and sarcosine, the latter being the main degradation pathway. For their part, in the study of Njoku et al (2020) [164] fungal strains were identified capable of degrading glyphosate; this study points out that the selected fungi biodegraded the herbicide through GOX pathway due to the presence of the AMPA metabolite, in exception of Aspergillus fumigatus FJAT-31052. Despite these studies, the metabolic processes related to the degradation of glyphosate in fungi have not been fully described.…”