Abstract.
Methylmercury
(MeHg),
accumulated
in
rice
grain,
is
highly
toxic
for
human.
Its
production
largely
driven
by
microbial
methylation
paddy
soils;
however,
dissolved
organic
matter
(DOM)
represents
a
hotspot
soil
biogeochemistry,
resulting
MeHg
production,
remain
poorly
understood.
Here,
we
conducted
hgcA
gene
sequencing
and
genome-resolved
metagenomic
analysis
to
identify
core
Hg-methylating
microbiome
investigate
the
effect
of
DOM
on
soils
across
Hg
contamination
gradient.
In
general,
communities
varied
with
degree
soils.
Surprisingly,
was
identified
exclusively
associated
concentration.
The
partial
Mantel
test
revealed
strong
linkages
among
composition,
Structural
equation
model
further
indicated
that
composition
significantly
impacted
concentration
(accounting
89
%);
while
crucial
determining
(65
%).
These
results
suggested
regulates
altering
microbiome.
presence
various
genes
carbon
metabolism
metagenome-assembled
genome
microorganisms
suggests
different
DOMs
stimulate
activity
methylate
Hg,
which
confirmed
pure
incubation
experiment
Geobacter
sulfurreducens
PCA
(core
microorganism)
amended
natural
solution
extracted
from
investigated
Overall,
simultaneously
changes
functional
thus
enhances
Biogeosciences,
Journal Year:
2025,
Volume and Issue:
22(6), P. 1543 - 1556
Published: March 24, 2025
Abstract.
Methylmercury
(MeHg),
accumulated
in
rice
grains,
is
highly
toxic
for
humans.
Its
production
largely
driven
by
microbial
methylation
paddy
soils;
however,
dissolved
organic
matter
(DOM)
a
critical
component
of
the
soil
biogeochemistry
process,
yet
its
interactions
with
microorganisms
involved
MeHg
remain
poorly
understood.
Here,
we
conducted
hgcA
gene
sequencing
and
genome-resolved
metagenomic
analysis
to
identify
core
Hg-methylating
microbiomes
investigate
effect
DOM
on
soils
across
Hg
contamination
gradient.
In
general,
communities
varied
degree
soils.
Surprisingly,
microbiome
was
identified
that
exclusively
associated
concentration.
The
partial
Mantel
test
revealed
strong
linkages
among
composition,
DOM,
Structural
equation
models
further
indicated
composition
significantly
impacted
concentration,
contributing
89
%
observed
variation,
while
plays
crucial
role
determining
accounting
65
%.
These
results
suggested
regulates
altering
microbiomes.
presence
various
genes
carbon
metabolism
metagenome-assembled
genome
suggests
different
stimulates
activity
methylate
Hg,
which
confirmed
pure
incubation
experiment
Geobacter
sulfurreducens
PCA
(a
microorganism)
amended
natural
solution
extracted
from
investigated
Overall,
simultaneously
changes
functional
thus
enhances
