by Sayer Ji
September 9, 2013
A new study
reveals that Roundup herbicide enhances the
growth of aflatoxin-producing fungi, lending
an explanation for the alarming increase in
fungal toxins recently discovered in U.S
corn, and revealing another way in which GM
farming is seriously undermining food
A new study lead by Argentinean researchers and published in the
Journal of Environmental Science and Health titled,
"Influence of herbicide glyphosate
on growth and aflatoxin B1 production by Aspergillus section
Flavi strains isolated from soil on in vitro assay," 
...adds to an increasing body of
research indicating that glyphosate (aka
Roundup), the primary herbicide
used in GM agriculture, is seriously undermining the quality of our
global food supply, and may help to explain recent observations that
GM corn heavy markets, such as the U.S., have a significant
Researchers from the Department of Microbiology and Immunology,
National University of Rio Cuarto, Cordoba, Argentina, set out to
evaluate the effect of glyphosate (Roundup) on the growth of aﬂatoxin
B1 production by strains of Aspergillus under different water
availabilities on maize based medium.
Aflatoxin B1, one of at least 14
different types, is a naturally occurring mycotoxin that is produced
by Aspergillus flavus and Aspergillus parasiticus, two species of
fungi that commonly effect cereal grains.
Known to be one of the most carcinogenic substances in existence,
aflatoxin B1 is classified by the International Agency for
Research on Cancer (IARC) as "Group
1, carinogenic to humans," with an oral, rat LD50 (the
dose that acutely kills 50% of a test group) of 5mg/kg - compare
that to a 6.4 mg/kg LD50 for potassium cyanide, which is used in
The authors of the study pointed out
that that little previous research has been performed on the role of
glyphosate on the growth rate of
aflatoxin-producing fungal species.
The researchers also described the
relevance this information has to the Argentinean corn market:
Aspergillus section Flavi and Nigri
Argentina is the world's second biggest exporter of maize (Zea
mays L.), and was responsible roughly for 15 percent of the
world's maize exports in the last three years.
During the harvest season 2011/2012
the maize production is expected to be of 20 million tons. These
cereal grains are colonize by several fungi communities,
including mycotoxigenic species.
Argentina's total acreage dedicated to
GM corn, while small in comparison to the U.S. majority stake in the
world market, is second only to the U.S. [See figure 1]
Acreage of GM
maize in million hectares
Also, Argentina's GM corn share in the total GM corn acreage
of their country is on par with the U.S. [see figured 2 below],
indicating that their environmental and toxicological situation in
regard to the food quality fallout from GM farming is likely very
GM maize share in
the total maize acreage of a country
Roundup Enhances Growth of Aflatoxin-Producing Fungi
In brief, the researchers discovered that all six different
concentrations of glyphosate tested decreased the lag phase of fungi
growth proportionately to the increase in glyphosate concentrations.
In other words, the glyphosate
enhanced the growth of the aflatoxin-producing Apergillus strains,
and at concentrations lower than the range generally detected in
Argentinean soils destined to crop production, specifically an
agricultural area belonging to the province of Buenos Aires.
In the author's words:
This study has shown that the eight
Aspergillus ﬂavus and A. parasiticus strains evaluated are able
to grow effectively and produce AFs [aflatoxins] in natural
medium with high nutrient status over a range of glyphosate
concentrations under different aW [water activity] conditions.
The figure below shows the influence of
glyphosate on growth and aflatoxin B1 production:
glyphosate on aflatoxin
The discovery that glyphosate enhances fungal growth
contradicts several previous studies, including a 2007 study
performed by US Department of Agriculture researchers,
which did not find that glyphosate increased Aspergillus flavus
The authors noted that their findings
are consistent with research on similar fungal strains, such as
Fusarium, which possesses high tolerance to
applied doses of glyphosate, and Rust fungi and Blight fungi,
 which exhibit enhanced growth on glyphosate-amended
"[S]everal studies have demonstrated
that microbial activity and/or biomass can be stimulated
following application of some glyphosate formulation to field
This may be explained by the fact that
glyphosate-tolerant species of fungi use glyphosate as a source of
'food,' utilizing available phosphate or amine structures that
result from its metabolic breakdown.
Indeed, previous studies indicate
glyphosate can be used by fungal strains as a "nutriment" and,
"energy substrate."  
Nightmare of GM Food Grows Darker
A major implication of the study is that there exists a
synergism between glyphosate (Roundup) and soil-borne pathogens,
which would lead to increased susceptibility to and severity of
disease in glyphosate-treated plants.
Not only would Roundup-ready corn
contain residues of highly toxic glyphosate, its 'inactive' yet
still highly toxic ingredients (surfactants), and metabolites (AMPA),
but it would also be more likely to contain aflatoxins - taken
together, represent a veritable nightmare of synergistic
toxicities, whose sum harms no regulatory agency yet adequately
The researchers conclude their paper with a cautionary note:
This situation suggests that
quantitative changes could occur in these fungi population
in the soil exposed to longtime action of this xenobiotic.
The survival of these microorganisms, capable to adapt to
different glyphosate concentration represents a
When one takes into account recent
research that Roundup herbicide contributes to the suppression
of beneficial lactic-acid producing gut bacteria, while
enhancing some of the most deadly known to man, e.g.
Clostridium botulinum (1
kilogram - 2.2 lbs - would be enough to kill the entire human
population), the days of casually classifying the ever-expanding
numbers of anti- or non-GMO supporters and activists as
alarmists, or GM food itself as "substantially
equivalent" to non-GM food, are over.
Those who continue to toe Biotech's
party-line, under the much maligned banner of checkbook
"Science," and in face of clear evidence against its safety,
will increasingly be perceived as morally, financially and even
legally liable for the damages being caused to exposed
Carla L Barberis, Cecilia S
Carranza, Stella M Chiacchiera, Carina E Magnoli.
Influence of herbicide glyphosate
on growth and aflatoxin B1 production by Aspergillus
section Flavi strains isolated from soil on in vitro
assay - J Environ Sci Health B. 2013
Tate & Lyle says aflatoxin in U.S.
corn complicates grain sourcing, Nov. 2012
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