Amazonian soil fungi are efficient degraders of glyphosate herbicide; novel isolates of Penicillium, Aspergillus, and Trichoderma

Pesticide residues that contaminate the environment circulate within the hydrological cycle can accumulate within the food chain and cause problems to both environmental and human health. Microbes, however, are well known for their metabolic versatility and the ability to degrade chemically stable substances, including recalcitrant xenobiotics. The current study focused on bio-prospecting within Amazonian rainforest soils to find novel strains fungi capable of efficiently degrading the agriculturally and environmentally ubiquitous herbicide, glyphosate. Of 50 fungal strains isolated (using culture media supplemented with glyphosate as the sole carbon-substrate), the majority were Penicillium strains (60%) and the others were Aspergillus and Trichoderma strains (26 and 8%, respectively). All 50 fungal isolates could use glyphosate as a phosphorous source. Eight of these isolates grew better on glyphosate-supplemented media than on regular Czapek Dox medium. LC-MS revealed that glyphosate degradation by Penicillium 4A21 resulted in sarcosine and aminomethylphosphonic acid.

Isolation and optimization of a glyphosate-degrading Rhodococcus soli G41 for bioremediation

A widely used herbicide for controlling weeds, glyphosate, is causing environmental pollution. It is necessary to remove it from environment using a cost-effective and eco-friendly method. The aims of this study were to isolate glyphosate-degrading bacteria and to optimize their degradative conditions required for bioremediation. Sixteen bacterial strains were isolated through enrichment and one strain, Rhodococcus soli G41, demonstrated a high removal rate of glyphosate than other strains. Response surface methodology was employed G41 strain to optimize distinct environmental factors on glyphosate degradation of G41 strain. The optimal conditions for the maximum glyphosate degradation were found to have the NH4Cl concentration of 0.663% and glyphosate concentration of 0.115%. Degradation analysis showed 47.1% of glyphosate in soil was degraded by G41 strain after 14 days. The presence of soxB gene in G41 strain indicates that the glyphosate is degraded via the eco-friendly sarcosine pathway. The results indicated that G41 strain has the potential to serve as an in-situ candidate for bioremediation of glyphosate polluted environments.

Bacillus megaterium Biodegradation Glyphosate

The Bacillus megaterium ability was evaluated in this paper to degrade the Glyphosate. organophosphorus pesticides, The bacteria re-cultured that isolated from other researches of Baghdad soils and morphological identification and biochemical tests besides by selectivity media. The (5 and 25) ppm showed the highest growth results were within two days to two months on mineral salt media. The highest glyphosate degradation ratio % were (70) % per 25 ppm/two months. Incubation period Increasing led to highest glyphosate degradation ratio% at (25) ppm led to conclusion that bacteria digestive the pesticides as carbon and nitrogen sources and will be well harvest it form contaminated areas.

Temperature and Aging Affect Glyphosate Toxicity and Fatty Acid Composition in Allonychiurus kimi (Lee) (Collembola)

Glyphosate is the most used herbicide worldwide, but enormous use of glyphosate has raised concerned about its environmental loadings. Although glyphosate is considered non-toxic, toxicity data for soil non-target organisms according to temperature and aging are scarce. This study examined the toxicity of glyphosate with the temperature (20 °C and 25 °C) and aging times (0 day and 7 days) in soil using a collembolan species, Allonychiurus kimi (Lee). The degradation of glyphosate was investigated. Fatty acid composition of A. kimi was also investigated. The half-life of glyphosate was 2.38 days at 20 °C and 1.69 days at 25 °C. At 20 °C with 0 day of aging, the EC50 was estimated to be 93.5 mg kg−1. However, as the temperature and aging time increased, the glyphosate degradation increased, so no significant toxicity was observed on juvenile production. The proportions of the arachidonic acid and stearic acid decreased and increased with the glyphosate treatment, respectively, even at 37.1 mg kg−1, at which no significant effects on juvenile production were observed. Our results showed that the changes in the glyphosate toxicity with temperature and aging time were mostly dependent on the soil residual concentration. Furthermore, the changes in the fatty acid compositions suggest that glyphosate could have a chronic effect on soil organisms.

W-Doped ZnO Photocatalyst for the Degradation of Glyphosate in Aqueous Solution

In this paper, the photocatalytic degradation of glyphosate by zinc oxide (ZnO) photocatalysts doped with tungsten (W) was investigated under solar simulated light. The photocatalysts were successfully synthesized through a simple precipitation method and subsequently characterized by different techniques: Raman spectroscopy, UV–Vis, N2 adsorption at −196 °C, X-ray diffraction, and SEM analysis. In particular, all the prepared catalysts were characterized by a crystallite size of about 28 nm and a hexagonal wurtzite structure. After the W doping, the bandgap energy decreased from 3.22 of pure ZnO to 3.19 for doped ZnO. This allowed us to obtain good results in terms of glyphosate degradation and simultaneous mineralization under solar simulated lamps, making the process environmentally friendly and with almost zero energy costs. In particular, the best photocatalytic performance was obtained with 100 W-ZnO (prepared with 1.5 mol% of W). With this catalyst, after 180 min of exposure to solar simulated light, the glyphosate degradation and mineralization was equal to 74% and 30%, respectively. Furthermore, it has been shown that the best catalyst dosage was equal to 1.5 g/L. The study on the influence of pH evidenced that the best photocatalytic performances are obtained at spontaneous (neutral) pH conditions. Finally, to determine the main reactive species in the glyphosate oxidation, the effects of different radical scavengers were tested. The results evidenced that the glyphosate oxidation mechanism seems to be related mainly to the O2•− generated under simulated solar light irradiation, but also in minor part to h+.

The fate of a hazardous herbicide: a DFT-based ab initio study on glyphosate degradation

Interaction of the well-known herbicide, glyphosate, with small radicals like hydroxyl and peroxyl radicals, such that the reaction between glyphosate radicals and oxygen molecules results in different species.

Role of soil bacterial consortia on glyphosate degradation and growth of maize seedlings

Pre-growing weed control by glyphosate herbicides is effective for increasing yield, but glyphosate residues in the soil might reduce soil quality and can accumulate in agricultural products. Naturally, microbes are able to breakdown glyphosate into nontoxic substances orthophosphate and glycine. Glyphosate degradation in soil by single soil microbes are reported elsewhere, but the information about glyphosate removal by soil bacterial consortia was limited. The objective of this research was to determine the effect of carbon (C), nitrogen (N), and phosphorus (P) composition in liquid media to increase glyphosate degradation and its degradation product by soil bacterial consortia and 2) verify the effect of bacterial consortia on maize seedlings growth, their N and P uptake, as well as total and soluble P in soil. Glyphosate degradation test was set up by incubating bacterial consortia in a different composition of C-N-P liquid basal media. Greenhouse experiment has been performed in a randomized block design to treat maize grown in Inceptisols with bacterial and glyphosate application. The results showed that C-N-P composition of liquid media affected the concentration of glyphosate, as well as orthophosphate and glycine as by-products. In-planta experiment verified that inoculation of glyphosate-degrading bacterial to maize seedling grown in glyphosate-contaminated soil enabled to enhance shoot dry weight of maize seedling and N and P uptake at 4 weeks after inoculation.

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

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.