Assessment of growth of Aspergillus spp. from agricultural soils in the presence of glyphosate

Abstract

Agriculture is one of the bases of the Argentine economy. Glyphosate is undoubtedly one of the most important herbicides used. The increasing consumption and the efficiency of glyphosate-based herbicides have encouraged several studies on their persistence in soils, their effects on soil microbiota and their degradation processes. Fungi have been reported as being the main herbicide-degrading microorganisms as well as the most tolerant to environmental stress conditions. This study evaluated the growth performance of Aspergillus section Flavi and Aspergillus niger aggregate strains on Czapek Dox media supplied with a commercial glyphosate formulation as sole source of carbon (CZC), phosphorus (CZP) or nitrogen (CZN). Six Aspergillus spp. strains were evaluated. Each medium was stab-inoculated with fungal spores from 7-day old cultures. Two measures of colony radii were taken daily. All of the Aspergillus section Flavi strains showed a significant increase (from 24 to 44%) in growth rate on the CZN medium, as compared to controls. The A. niger aggregate strains exhibited the same behavioral pattern under all the conditions tested, except on the CZN medium. Velutinous or slightly floccose colonies with abundant sporulation were observed on CZP. Moreover, the colonies produced sparse sporulation on CZC or CZN media, being their appearances completely different from those on the CZP medium. This study establishes that A. section Flavi and A. niger aggregate strains can grow in vitro in the presence of glyphosate, especially when it is used as a sole source of phosphorus or nitrogen.

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

“…The biomass assay described by Arfarita et al (Arfarita et al, 2011) have previously been used as a robust methodology for the screening of microorganisms able to use glyphosate as nutrient source. A similar conclusion about this methodology was reached out by other workers with similar design (Arfarita et al, 2016;Carranza et al, 2016Carranza et al, , 2017. The selected isolate Penicillium 4A21 degraded the herbicide glyphosate by over 42% in just 14 days in submerged fermentation.…”

Re-registration Challenges of Glyphosate in the European Union

“…A proteomic analysis indicated protein expression modulation and possible metabolic disturbances . Similar effects were not observed for Aspergillus section Flavi strains and A. niger (Carranza et al, 2017). Negative effects of glyphosate and/or N fertilization on soil enzymes and arbuscular mycorrhizal fungi were reported (Nivelle et al, 2018).…”

Effect of in vitro glyphosate on Fusarium spp. growth and disease severity in maize

“…Xenobiotic compounds, such as pesticides, also have a considerable effect on fungal development. Previous studies have shown significant changes on both growth rate and mycotoxin production of Aspergillus species caused by GP …”

“…Previous studies have shown significant changes on both growth rate and mycotoxin production of Aspergillus species caused by GP. [10][11][12][13][14][15] Several maize (Zea mays L.) diseases can affect yield, nutritive value, and quality of the grains. Fusarium sp.…”