Environmental Science & Technology,
Год журнала:
2022,
Номер
56(23), С. 16848 - 16856
Опубликована: Ноя. 17, 2022
Dehydrochlorination
is
one
of
the
main
(thus
far
discovered)
processes
for
aerobic
microbial
transformation
hexachlorocyclohexane
(HCH)
which
mainly
catalyzed
by
LinA
enzymes.
In
order
to
gain
a
better
understanding
reaction
mechanisms,
multi-element
compound-specific
stable
isotope
analysis
was
applied
evaluating
α-
and
γ-HCH
transformations
LinA1
LinA2
The
isotopic
fractionation
(εE)
values
particular
elements
(+)α-HCH
(εC
=
−10.8
±
1.0‰,
εCl
−4.2
0.5‰,
εH
−154
16‰)
were
distinct
from
(−)α-HCH
−4.1
0.7‰,
−1.6
0.2‰,
−68
10‰),
whereas
dual-isotope
patterns
almost
identical
both
enantiomers
(ΛC–Cl
2.4
0.4
2.5
0.2,
ΛH–C
12.9
14.9
1.1).
εE
−7.8
1.0‰
−7.5
0.8‰
(εC),
−2.7
0.3‰
−2.5
0.4‰
(εCl),
−170
25‰
−150
13‰
(εH),
respectively.
Similar
ΛC–Cl
(2.7
0.2
2.9
0.2)
observed
as
well
similar
(20.1
2.0
18.4
1.9),
indicating
mechanism
enzymes
during
transformation.
This
first
data
set
on
3D
enzymatic
dehydrochlorination,
gave
more
precise
characterization
bond
cleavages,
highlighting
potential
characterize
different
(e.g.,
dehydrochlorination
reductive
dehalogenation).
Chemosphere,
Год журнала:
2024,
Номер
352, С. 141488 - 141488
Опубликована: Фев. 16, 2024
By
assessing
the
changes
in
stable
isotope
compositions
within
individual
pesticide
molecules,
Compound
Specific
Isotope
Analysis
(CSIA)
holds
potential
to
identify
and
differentiate
sources
quantify
degradation
environment.
However,
environmental
application
of
CSIA
is
limited
by
general
lack
knowledge
regarding
initial
isotopic
composition
active
substances
commercially
available
formulations
used
farmers.
To
address
this
limitation,
we
established
a
database
aimed
at
cataloguing
disseminating
signatures
commercial
expand
use
CSIA.
Our
study
involved
collection
25
analytical
standards
120
from
23
manufacturers.
Subsequently,
59
were
extracted,
each
their
substance
was
analyzed
for
both
δ
The Science of The Total Environment,
Год журнала:
2024,
Номер
931, С. 172858 - 172858
Опубликована: Май 5, 2024
Multi-element
compound-specific
stable
isotope
analysis
(ME-CSIA)
allows
monitoring
the
environmental
behavior
and
transformation
of
most
common
persistent
contaminants.
Recent
advancements
in
analytical
techniques
have
extended
applicability
ME-CSIA
to
organic
micropollutants,
including
pesticides.
Nevertheless,
application
this
methodology
remains
unexplored
concerning
harmful
insecticides
such
as
methoxychlor,
a
polar
organochlorine
pesticide
usually
detected
soil
groundwater.
This
study
introduces
methods
for
dual
carbon
chlorine
(δ
Abstract.
The
prediction
of
pesticide
dissipation
on
the
catchment
scale
through
hydrological
models
often
encounters
challenges
due
to
limited
availability
field
data
capable
distinguishing
between
degradative
and
non-degradative
processes.
This
limitation
complicates
calibration
frequently
results
in
equifinality,
impeding
reliable
forecast
persistence
soil
its
transportation
from
agricultural
plots
outlet.
study
examines
benefits
integrating
Compound-Specific
Isotope
Analysis
(CSIA)
improve
predictive
accuracy
assessing
off-site
transport
at
scale.
research
was
conducted
a
47-ha
crop
catchment,
focusing
widely
used
pre-emergence
herbicide
S-metolachlor.
A
novel
conceptual
model,
named
PIBEACH,
developed
predict
daily
rivers,
incorporating
changes
carbon
isotopic
signatures
(δ13C)
targeted
during
degradation.
Parameter
model
uncertainties
were
estimated
using
Generalized
Likelihood
Uncertainty
Estimation
(GLUE)
method.
inclusion
S-metolachlor
concentrations
topsoil
their
associated
δ13C
values
resulted
more
than
two-fold
reduction
related
degradation
half-life
six
metrics
transport.
Moreover,
indicates
that
moderate
yet
sampling
effort
can
effectively
identify
hot-spots
hot-moments
when
isotope
fractionation
is
integrated
into
model.
In
summary,
incorporation
CSIA
distributed
holds
potential
alleviate
parameter
therewith
significantly
improving
our
ability
dynamics
Biotechnology and Bioengineering,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 16, 2025
The
bioaugmentation
performance
is
severely
reduced
in
the
treatment
of
high-saline
pesticide
wastewater
because
growth
and
degradation
activity
degraders
are
significantly
inhibited
by
high
salt
concentrations.
In
this
study,
a
heterologous
biodegradation
pathway
comprising
seven
genes
mpd/pnpABCDEF
responsible
for
bioconversion
p-nitrophenol
(PNP)-substituted
organophosphorus
pesticides
(OPs)
into
β-oxoadipate
encoding
Vitreoscilla
hemoglobin
(VHb)
green
fluorescent
protein
(GFP)
were
integrated
genome
salt-tolerant
chassis
Halomonas
cupida
J9,
to
generate
genetically
engineered
halotolerant
degrader
J9U-MP.
RT-PCR
assays
demonstrated
that
nine
exogenous
successfully
transcribed
mRNA
Gas
chromatography
analysis
methyl
parathion
(MP)
its
intermediates
expressed
MP
hydrolase
PNP-degrading
enzymes
PnpABCD
show
obvious
toward
specific
substrates
Stable
isotope
showed
J9U-MP
able
efficiently
convert
13C6-PNP
13CO2,
demonstrating
complete
mineralization
high-salt
media.
stable
during
passage
culture,
genomic
integration
does
not
negatively
influence
Under
oxygen-limited
conditions,
VHb-expressing
inhibition
significant
reduction
rate.
A
real-time
monitoring
system
with
enhanced
GFP
used
track
motion
bioremediation.
Moreover,
50
mg/L
(i.e.,
PNP
HQ)
completely
degraded
within
12
h
supplemented
60
g/L
NaCl.
After
3
days
incubation,
25
was
converted
13CO2
Our
results
highlight
power
synthetic
biology
creating
new
pollutant-mineralizing
strains.
strong
competitive
advantages
high-salinity
low-oxygen
environments
make
suitable
situ
OP
wastewater.
