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African Journal of Biotechnology Vol. 9 (26), pp. 4067-4074, 28 June, 2010
Available online at http://www.academicjournals.org/AJB
ISSN 1684–5315 © 2010 Academic Journals
Full Length Research Paper
Biodegradation of glyphosate herbicide in vitro using
bacterial isolates from four rice fields
A. N. Moneke*, G. N. Okpala and C. U. Anyanwu
Department of Microbiology, University of Nigeria, Nsukka, Enugu State, Nigeria.
Accepted 18 May, 2010
Glyphosate is a compound used as herbicide in the control and/or killing of grasses and herbaceous
plants. It can be used in no-till agriculture, to prepare fields before planting, during crop development and
after crop harvest. Because of its toxicity to non-target organisms, there is need to decontaminate
glyphosate contaminated soils and bioremediation is a very useful alternative to conventional cleanup
methods. The success of this will depend on isolating bacteria with the ability to degrade glyphosate in a
changing environment. The abilities of five bacterial species (Escherichia sp, Azotobacter sp.,
Alcaligenes sp., Acetobacter sp. and Pseudomonas fluorescens) to degrade glyphosate herbicide under
varying environmental conditions were evaluated in this study. The isolates were screened for
glyphosate utilization using mineral salt medium containing glyphosate as carbon and/or phosphorus source.
Of the five bacterial isolates, P. fluorescens and Acetobacter sp. showed the capacity to utilize glyphosate
efficiently and were therefore used for further biodegradation studies. Time course of growth of the
isolates on mineral salt medium containing glyphosate showed that both grew significantly (P < 0.05).
Microbial growth during the study was monitored by measuring the optical density at 660 nm. The
comparative effects of glyphosate as carbon and/or phosphorus source on the growth of the isolates
showed that there was significant (P < 0.05) growth in the medium containing glucose and glyphosate.
The effects of different concentrations of glyphosate on the growth of the isolates (P. fluorescens and
Acetobacter sp) were evaluated. Significant (P < 0.05) growth was observed at lower concentrations (7.2 -
25 mg/ml) of glyphosate. No inhibition of growth was observed at high concentrations (100 - 250 mg/ml),
indicating that the isolated bacteria can tolerate up to 250 mg/ml of glyphosate. However, there was
subsequent decrease in growth of both isolates as the concentration of glyphosate increased. This study
showed that P. fluorescens and Acetobacter sp. exhibited a high capacity to efficiently degrade
glyphosate under the environmental conditions studied. Thus, the organisms can be exploited for
biodegradation of glyphosate and should be studied for their ability to degrade other organophosphates.
Key words: Glyphosphate herbicide, degradation process.
INTRODUCTION
The intensive use of herbicides in rice-based cropping
systems is a general practice and thus a matter of
environmental concern. This is as a result of the potential
hazardous effects of these chemicals on soil biological
processes, non-target organisms and pollution of streams
*Corresponding author. E-mail: annymoneke@yahoo.com. Tel:
08033357734.
and rivers through runoffs. The common herbicides in
use include 2,4-dicholorophenoxyacetic acid (2,4-D) and
Roundup® (isoproplyamine salt of glyphosate).
Glyphosate on its own may be relatively harmless to
humans. It is however formulated with surfactants such
as polyoxyethylene amine (POEA) which is more toxic than
glyphosate alone (Atkinson, 1985). Also, 2,4-
dichlorophenoxy-acetic acid which is used by most
farmers to spike glyphosate in order to boost its efficacy
increases the toxicity of glyphosate.
4068 Afr. J. Biotechnol.
Table 1. State and location from where the soil
samples were collected.
State Location Code
Anambra Omor OMR
Anambra Omasi OMS
Enugu Adani ADA
Ebonyi Abakaliki AKL
Organophosphates, including glyphosate, account for
half of the pesticides used worldwide with glyphosate
based formulations such as Roundup®, Accord® and
Touchdown® consisting the commonest types used for
agricultural purposes (Franz et al., 1997). Glyphosate is a
broad spectrum, non-selective herbicide used in the
control and/or killing of grasses, herbaceous plants,
including deep rooted perennial weeds, brush, some
broad-leaf trees and some shrubs (United States
Department of Agriculture (USDA), 2000; Cox, 2000). It
can be used in no-till agriculture, to prepare fields before
planting, during crop development and after crop harvest
(USDA, 2000). Its mode of action is the
inhibition of 5-
enolpyruvylshikimate-3-phosphate synthase, resulting
in
the depletion of essential aromatic amino acids needed
for
plant survival (Arhens, 1994; Zablotowicz and Reddy,
2004). Although most living organisms lack this metabolic
route such that they would not be potentially affected by
this herbicide, the environmental consequences of the
widespread use of glyphosate have been reported (Cox,
2000; Santillo et al., 1989). On application, glyphosate
remains unchanged in the soil for varying lengths of time,
as a result of its adsorption on clay particles and organic
matter present in the soil (Penaloza-Vazquez et al.,
1995). The removal of glyphosate from the environment
is usually by microbiological processes as chemical
process of degradation is ineffective because of the
presence of highly stable bonds (carbon-phosphorus
bond) present in the compound (Gimsing et al., 2004).
Glyphosate is microbially degraded in soil and
water and
has a reported field half-life of 47 days and a laboratory
half-life of < 25 days (Ahrens, 1994). Studies of
glyphosate degrading bacteria have involved selection
for, and isolation of pure bacterial strains with enhanced or
novel detoxification capabilities for potential uses in
biotechnology industry and biodegradation of polluted
soils and water. Microorganisms known for their ability to
degrade glyphosate in soil and water include
Pseudomonas sp strain LBr (Jacob et al., 1988),
Pseudomonas fluorescens (Zboinska et al., 1992),
Arthrobacter atrocyaneus (Pipke et al., 1988) and
Flavobacterium sp. (Balthazor and Hallas, 1986). Bacteria
degrade glyphosate via two general pathways leading to
the intermediate production of either glycine or
aminomethylphosphonate (AMPA). The use of glyphosate
based formulations in rice farming is a common practice
in south eastern Nigeria and in oil palm (Elaeis
guineensis) plantation in the rainforest area of Nigeria.
No work has been done to identify glyphosate degrading
bacteria from rice farms in Nigeria and the conditions that
enhance the degradation process. The main objectives
of the present study are the isolation and identification of
glyphosate utilizing bacteria from rice farms using an
enrichment culture technique, assessment of the growth
response of the isolates in liquid medium containing
different concentrations of glyphosate and analysis of the
comparative effects of glyphosate as carbon or
phosphorus source on the isolates.
MATERIALS AND METHODS
Chemicals used
The isopropylamine
salt of glyphosate known as Roundup®
(containing 360 g active ingredient/L of glyphosate, Monsanto) was
purchased from a local dealer’s store in Nsukka, Enugu state,
Nigeria. All other chemicals were of the highest purity commercially
available.
Collection of soil samples
Soil samples were obtained from four rice fields located at Adani in
Enugu State, Nigeria, Omor and Omasi in Anambra State, Nigeria
and Abakaliki in Ebonyi State, Nigeria, all in south eastern Nigeria.
These rice fields are known to have been previously exposed to
glyphosate-based formulation (Roundup®) for long periods of time.
Soil samples were collected from depths of 0 - 15 cm from three
different sites in each of the four locations. Soil samples from each
site were thoroughly mixed. They were designated as shown in
Table 1. All samples were placed in sterile polyethylene bags and
taken immediately to the laboratory and stored at 4°C before use
within 24 h (Nannipieri, 1994).
Isolation medium
A modified mineral salts medium (MSM) of Dworkin and Foster
(1958) consisting of (g/l) (NH
4
)
2
SO
4
,
0.375;
MgSO
4
, 0.075; CaC0
3
,
0.03;
FeSO
4
.7H
2
O, 0.001; H
3
BO
3
, 0.000001, MnSO
4
, 0.000001 and
yeast extract, 0.0053 was used. Phosphate buffer was replaced by
tris buffer 6.05 g/L and pH was adjusted to 7.0. All glasswares were
washed with 1 N HCl and thoroughly rinsed with deionized water to
remove contaminating phosphate before use. The medium was
autoclaved at 121°C and 15 psi for 15 min prior to the addition of
the filter sterilized Roundup® (isopropylamine salt of glyphosate)
and glucose (1.0) autoclaved at 110°C and 10 psi as carbon
source.
Isolation of glyphosate utilizing bacteria
The soil samples were air-dried and sieved using a 2 mm mesh. 5 g
of each soil sample was suspended in 250-ml Erlenmeyer flasks
containing a mixture of 50 ml of mineral salts medium and 1 ml of
Roundup® (7.2 mg/ml of glyphosate). This concentration was used
because it is equivalent to the field application rate. The flasks were
incubated on a rotary shaker (Gallenkamp, England) at 120 rpm for
7 days at 30°C. The above steps were repeated by taking 1.0 ml of
sample from each broth culture and transferred to fresh enrichment
medium followed by incubation as described for 7 days. Isolation
was done using the spread plate method on the solid mineral salts
medium described above with added glyphosate. The plates were
incubated at 30°C for 5 days. Morphologically distinct colonies were
re-isolated and were repeatedly sub-cultured on nutrient agar
(Fluka). Identity of the isolates was affirmed after characterization
by standard bacteriological methods (Holt et al., 1994; Cheesbrough,
1984). Stock cultures were maintained in nutrient agar slants at
4°C.
Inoculum preparation and standardization
Inocula used for the study were prepared by inoculating isolates
into nutrient broth and incubated at 30°C for 24 h using sterile
normal saline; the cells from the above cultures were resuspended
to a 0.5 McFarland nephelometer standard (Optical density of 0.17
at 660 nm).
Glyphosate utilization patterns of the different isolates
A 1.0 ml portion of each isolate was inoculated into 150 ml of the
screening medium (contained in a 500-ml flask) which is the
isolation medium without yeast extract. It contained 3 ml of roundup
(7.2 mg/ml of glyphosate). The flasks were incubated on a rotary
shaker (Gallenkamp, England) at 120 rpm for 180 h at 30°C. The
ability of each isolate to utilize glyphosate was measured based on
the turbidity of the medium at 660 nm using a spectrophotometer
(Spectronic 20, USA).
Determination of time course of the growth of P. fluorescens
and Acetobacter sp.
500-ml Erlenmeyer flasks containing 150 ml of the sterile screening
medium was prepared and 3 ml of roundup (containing 7.2 mg/ml of
glyphosate) was added to each flask. 1 ml of the inoculum (0.5
Macfarlane standards) of each selected isolate was used to
inoculate each flask (experiments were carried out in 3 replicates).
The two isolates used were selected based on their utilization
patterns. The medium was then incubated at 30°C for 192 h on a
shaker at 120 rpm. 5 ml of the culture medium was collected from
each flask at 12 h intervals and assayed for growth by measuring
the optical density at 660 nm using a spectrometer.
Comparative role of glyphosate as carbon or phosphorus
source
The screening medium (150 ml) was prepared as earlier described
and 3.0 ml filter-sterilized roundup (containing 7.2 mg/ml of
glyphosate) was added as phosphorus or carbon source. When
used as carbon source, denoted by Gly and Pi, the medium
consisted of the following (g/L): (NH
4
)
2
SO
4
,
0.375; MgSO
4,
0.075;
CaC0
3
,
0.03;
FeSO
4
.7H
2
O, 0.001; H
3
BO
3
, 0.000001; MnSO
4
,
0.000001; NaHPO
4
, 6.0
and KH
2
PO
4
, 2.0. When used as carbon
and phosphorus source, denoted by (Glyphosate), the medium
consisted of the following (g/L): (NH
4
)
2
SO
4
,
0.375;
MgSO
4,
0.075;
CaC0
3
,
0.03;
FeSO
4
.7H
2
O, 0.001; H
3
BO
3
, 0.000001; MnSO
4
,
0.000001; tris buffer 6.05 g. When used as phosphorus source
denoted by (Gly and Glu), the medium consisted of the following
(g/L): (NH
4
)
2
SO
4
,
0.375;
MgSO
4,
0.075; CaC0
3
,
0.03;
FeSO
4
.7H
2
O,
Moneke et al 4069
0.001; H
3
BO
3
, 0.000001; MnSO
4
, 0.000001; glucose, 1.0; tris buffer
6.05 g. The media was incubated at 30°C for 120 h on a shaker at
120 rpm. 5 ml of the culture medium was collected from each flask
at 12 h intervals and assayed for growth by measuring the optical
density at 660 nm using a spectrometer.
Effects of different concentrations of glyphosate on the growth
of the isolates
Aliquots (1.0 ml) of 24 h old bacterial cultures (0.5 MacFarland
standard) grown in nutrient broth were inoculated into 500-ml
Erlenmeyer flasks containing 150 ml of MSM supplemented with
various concentrations of glyphosate (25, 50, 100 and 250 mg/ml).
A control was maintained with MSM supplemented with 7.2 mg/ml
of glyphosate. Bacterial growth was monitored by withdrawal of 5.0
ml of culture sample immediately after inoculation for the 0 h and
every 12 h up to 108 h of incubation and optical density was measured
at 660 nm.
Treatment effects on the growth of the bacterial isolates at the
different time periods were analysed using 2-way ANOVA.
RESULTS
Isolation of glyphosate utilizing bacteria
The preliminary studies with glyphosate as phosphorus
source showed that a total of twelve bacterial isolates
were able to grow in the presence of glyphosate as sole
phosphorus source. On further sub-culturing on solid
medium, five isolates consistently grew on the MSM
enriched with glyphosate as phosphorus source. They
are: Acetobacter sp. - G ADA3, Escherichia sp. - G AKL2,
P. fluorescens - G AKL5, Azotobacter sp. - G OMR1 and
Alcaligenes sp. - G OMS1.
Glyphosate utilization patterns of the different
isolates
The five bacterial isolates were screened for glyphosate
utilization by measuring their growth turbidimetrically at
660 nm. Of the five bacterial isolates grown on the
medium containing glyphosate as sole phosphorus
source, P. fluorescens significantly (P < 0.05) utilized
glyphosate (mean OD 0.1268). This was followed by
Acetobacter sp., Azotobacter sp. and Alcaligenes sp.
(mean OD 0.1069, 0.0858 and 0.0841, respectively).
Escherichia sp. did not show any appreciable growth as
shown in Figure 1.
Growth kinetics of P. fluorescens and Acetobacter
sp. in glyphosate
The growth kinetics of P. fluorescens and Acetobacter sp.
were further monitored over time at 660 nm, using the
MSM enriched with glyphosate as sole phosphorus source.
Their growths were both significant (P < 0.001), but that
4070 Afr. J. Biotechnol.
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180
Time (Hours)
A b s o rb a n c e (6 6 0 n m )
Acetobacter sp Escherichia sp P seudomo nas fluo rescens Azo to bacter s p Alcaligenes sp
Figure 1. Screening of the isolates for glyphosate utilization.
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192
Time (Hours)
Ab so rb an ce (660 n m )
Acetobacter sp Pseudomonas fluorescens
Figure 2. Growth kinetics of Acetobacter sp. and P. fluorescens on glyphosate.
but that of P. fluorescens was significantly (P < 0.05)
higher than that of Acetobacter sp. as shown in Figure 2.
Comparative role of glyphosate as carbon or
phosphorus source
The ability of glyphosate to serve as carbon source,
phosphorus source, carbon and phosphorus source was
monitored. Optical density measurement at 660 nm was
used to monitor increase in cell numbers. The growth of
Acetobacter sp. was non-significantly (P < 0.05) higher in
the Glucose and Glyphosate (Gly and Glu) medium
(mean OD value = 0.0907) when compared to P.
fluorescens (mean OD value = 0.09003) (Figure 3). On
the medium with glyphosate as carbon and phosphorus
source, the growth of P. fluorescens was significantly
higher when compared to Acetobacter sp. The growth
kinetics of the isolates in the different carbon sources
showed that there was progressive increase in growth of
the isolates when glyphosate was used as a phosphorus
source and glucose as carbon source. The growth of
Acetobacter sp. after 24 h incubation on Glu and Gly
medium was more significant (P < 0.05) with a mean OD
value of 0.0933 when compared with the growth on the
GPi, glyphosate and the control (Figure 4). Also, the
growth of Acetobacter sp. on the GPi medium peaked
after 36 h with mean OD value of 0.02733, which was
significantly (P < 0.05) higher than growth on the medium
containing glyphosate and the control. After 36 h of
incubation, the growth on the Glu and Gly medium
consistently increased till the end of the monitoring (120
Moneke et al 4071
0.00000
0.01000
0.02000
0.03000
0.04000
0.05000
0.06000
0.07000
0.08000
0.09000
0.10000
Glucose Gly and Glu Glyphosate Gly and Pi
Carbon source
Optical Density (660nm )
Acetob acter sp Pseudomonas fluorescens
Figure 3. Comparative effect of glyphosate as carbon or phosphorus source on Acetobacter sp. and P
fluorescens.
0.00000
0.05000
0.10000
0.15000
0 12 24 36 48 60 72 84 96 108 120
Time (Hrs)
Absorbance (660nm)
Glucose Glyphosate Gly and Glu Gly and Pi
Figure 4. Growth kinetics of Acetobacter sp. in glyphosate as carbon or phosphorus source.
h). The growth of P. fluorescens in the Glu and Gly
medium followed a similar pattern as that of Acetobacter sp.
as shown in Figure 5.
Effects of different glyphosate concentration on the
growth of Acetobacter sp. and P. fluorescens
The growth of Acetobacter sp. and P. fluorescens in
different concentrations of glyphosate gave an inverse
result as shown in Figure 6. As the concentration of
glyphosate increased there was a corresponding
decrease in the growth of the isolates. The highest
growth was observed in the control (7.2 mg/ml) which
contained the least concentration of glyphosate. The
growth kinetics of both isolates in increasing
concentrations of glyphosate followed a similar pattern
with a lag phase of about 12 h and steady increase in
growth as seen in Figures 7 and 8. After 84 h of
incubation the growth of P. fluorescens in medium
containing 25 mg/ml of glyphosate increased significantly
(P < 0.05) when compared with its growth in the medium
with 7.2 mg/ml of glyphosate till the end of the monitoring
at 108 h.
DISCUSSION
Twelve bacterial isolates were initially isolated from rice
field soil samples. On further sub-culturing on solid media
enriched with glyphosate, only five showed the capacity
to grow in the presence of the herbicide. The five
bacterial isolates were identified as Acetobacter sp.,
Escherichia sp., P. fluorescens, Azotobacter sp., and
4072 Afr. J. Biotechnol.
0.00000
0.05000
0.10000
0.15000
0 12 24 36 48 60 72 84 96 108 120
Time (Hrs)
Absorbance (660nm)
Glucose Glyphosate Gly and Glu Gly and Pi
Figure 5. Growth kinetics of P. fluorescens in glyphosate as carbon or phosphorus source.
0.0000
0.0200
0.0400
0.0600
0.0800
0.1000
0.1200
0.1400
0.1600
Optical density (660 nm )
7.2mg/ml 25mg/ml 50mg/ml 100mg/ml 250mg/ml
Acetobacter sp
Pseudomonas fluorescens
Figure 6. Effects of the different concentrations of glyphosate on the growth of Acetobacter sp.
and P. fluorescens.
0.000
0.050
0.100
0.150
0.200
0.250
0 12 24 36 48 60 72 84 96 108
Time (hours)
Ab so rb a n ce (660n m )
7.2mg/ml 25mg/ml 50mg/ml 100mg/ml 250mg/ml
Figure 7. Growth kinetics of Acetobacter sp. on the different concentrations of glyphosate.
Moneke et al 4073
0.0000
0.0500
0.1000
0.1500
0.2000
0 12 24 36 48 60 72 84 96 108
Time (Hours)
A b s o rb a n c e (6 6 0 n m )
7.2mg/ml 25mg/ml 50mg/ml 100mg/ml 250mg/ml
Figure 8. Growth ksinetics of P. fluorescens on the different concentrations of glyphosate.
Alcaligenes sp. The results of this study, which showed a
reduction in the number of bacterial species grown on
glyphosate solid medium, are consistent with the report of
Busse et al. (2001) who showed that culturable bacteria
and fungi are usually reduced in number or eliminated
when extracted from soil or grown on solid media
containing glyphosate. Other studies (Quinn et al., 1988;
Santos and Flores, 1995; Kryzsko-Lupicka and Orlik,
1997) had found similar reductions in population counts
when glyphosate was added to culture media. Toxicity of
the artificial media is expected to be based on the mode
of action of glyphosate (inability of the organism to
synthesize the needed aromatic amino acids). Unlike the
response in artificial media, no toxicity was expressed
when glyphosate was added to soil in laboratory
bioassays (Busse et al., 2001).
The isolated bacterial species had previously been
obtained from other soil samples (Zboinska et al., 1992,
Franz et al., 1997). Of the seven identified bacterial species,
two (Acetobacter sp. and P. fluorescens) were selected
for further biodegradation studies based on their short lag
phase and rapid utilization of glyphosate. Many
Pseudomonas species have been used extensively in the
degradation and/or metabolism of glyphosate (Jacob et
al., 1988; Shinabarger et al., 1984; Kishore and Jacob,
1987; Talbot et al., 1984. However, Zboinska et al. (1992)
reported that P. fluorescens could not utilize glyphosate.
The strain of P. fluorescens used in this study was not
only able to utilize glyphosate but was also able to thrive
at high concentrations of the herbicide. The use of
Acetobacter in the degradation/metabolism of glyphosate
has not been reported.
Both organisms used in this study showed appreciable
growth in the culture medium containing glyphosate as
sole phosphorus source. The differences observed in the
growth of the isolates in the medium are indicative of the
differences between the organisms in tolerating the
herbicide. The short lag phase, coupled with rapid growth
of the two isolates, showed effective utilization of
glyphosate by the selected isolates. P. fluorescens attained
maximum growth and peaked at 132 h incubation, while
Acetobacter sp. achieved maximum growth and peaked
at 72 h incubation. There have been several reports on
the ability of microorganisms, including some Pseudomonas
sp., to effectively utilize glyphosate by naturally
synthesizing appropriate enzymes or as a result of genetic
mutation (Jacob et al., 1988; Shinabarger et al., 1984;
Kishore and Jacob, 1987). So far, there has been no
report on the ability of P. fluorescens to utilize glyphosate
as sole phosphorus or carbon source. The high capacity
of these two organisms to utilize this herbicide in vitro
could be attributed to their previous contact with the
herbicide in the soil (rice fields) from where they were
isolated. It is also possible that the organisms have
undergone genetic mutation leading to the adaptability of
the organisms to their microenvironment.
The results of the comparative role of glyphosate as
carbon or phosphorus source for the two isolates showed
that glyphosate serves as a better phosphorous source
than as a carbon source. Many bacterial isolates have
been reported to utilize glyphosate as a phosphorus
source (Liu et al., 1991; Balthazor and Hallas, 1986; Dick
and Quinn, 1995). Of the two isolates used in the present
study, P. fluorescens demonstrated a better capacity to
utilize glyphosate as carbon and phosphorus source.
Glyphosate served as a better phosphorus source than
carbon source for the Acetobacter sp. The presence of
inorganic phosphate in the growth medium affected the
effective uptake of glyphosate in both organisms. This is
because inorganic phosphate has been reported to sup-
4074 Afr. J. Biotechnol.
press the genes coding for the C-P lyase system and
thus make them unable to metabolise glyphosate (Liu et
al., 1991). Our results in this study agree with this report.
The results of this study showed that increase in
glyphosate concentration led to a concomitant decrease
in the growth of the isolates. This is in contrast with the
report of Amoros et al. (2007), who, while studying the
effects of roundup (glyphosate) at different concentrations
(50 and 100 mg/l) observed an increase in Aeromonas
counts in contrast with the control which contained no
glyphosate. However, Carlisle and Trevors (1988)
observed that glyphosate can either stimulate or inhibit
soil microorganisms depending on the soil type or
herbicide concentration. In our study, high cell density
was recorded for both isolates at glyphosate
concentrations of 7.2 - 50 mg/ml after 24 h at 30°C.
However, at higher concentrations (100 and 250 mg/ml),
the cell density was very low compared with the control
(7.2 mg/ml). Even though a severe decline in growth of
the organisms occurred at high concentrations (100 and
250 mg/ml), the isolates were still able to tolerate 250
mg/ml of glyphosate. A possible explanation may be the
presence of novel degradative systems in the organisms.
Conclusion
Herbicides are extensively used in farming practices.
Some of the farmers, due to illiteracy and impatience,
apply more than the stipulated quantity of herbicide per
application. These chemicals may persist for long periods
of time in the environment, whereby they may affect non-
target organisms. This study reports the isolation and
identification of two bacterial species, P. fluorescens and
Acetobacter sp. that possess the capacity to utilize
glyphosate. The ability of these isolates to utilize
glyphosate effectively provides a means of removing this
compound from the environment. Thus the capacity of
the isolates to survive and grow in the presence of high
concentrations of the herbicide marks them out as good
candidates for the bioremediation of glyphosate-polluted
environments.
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