Anammox
is
an
energy-efficient
nitrogen
removal
process
in
which
anammox
bacteria
(AnAOB)
oxidize
NH4+-N
to
N2
using
NO2--N
as
the
electron
acceptor.
Recent
evidence
suggests
that
AnAOB
can
perform
extracellular
transfer
(EET),
potentially
coupling
Fe(III)
reduction
with
oxidation
(Feammox).
However,
whether
directly
participate
Feammox
within
complex
wastewater
treatment
systems
remains
unclear.
Here,
we
investigated
iron-mediated
metabolism
pathways
a
microaerobic
granular
sludge
(MGS)
reactor
by
integrating
enzyme
inhibition
assays
analyses
of
gene
dynamics
and
co-occurrence
patterns
nitrogen-
iron-cycling
genes.
Results
demonstrate
contributed
activity.
The
iron
CT573071,
coding
porin-cytochrome
c
protein
associated
EET,
co-occurred
hao,
hzsABC,
hdh
genes
Candidatus
Kuenenia,
suggesting
its
role
Feammox.
Furthermore,
four
high-quality
metagenome-assembled
genomes
(MAGs)
affiliated
Kuenenia
stuttgartiensis_A
harbored
hao-like,
genes,
along
hao-cluster,
catalyzes
hydroxylamine.
This
genomic
further
supports
their
dual
metabolic
capacity.
Metatranscriptomic
analysis
confirmed
CT573071
upregulation
coexpression
These
findings
establish
potential
K.
Feammox,
providing
novel
insights
into
low-strength
systems.
Biodegradation,
Journal Year:
2023,
Volume and Issue:
35(1), P. 47 - 70
Published: July 12, 2023
Abstract
In
the
context
of
anaerobic
ammonium
oxidation
process
(anammox),
great
scientific
advances
have
been
made
over
past
two
decades,
making
anammox
a
consolidated
technology
widely
used
worldwide
for
nitrogen
removal
from
wastewaters.
This
review
provides
detailed
and
comprehensive
description
process,
microorganisms
involved
their
metabolism.
addition,
recent
research
on
application
with
alternative
electron
acceptors
is
described,
highlighting
biochemical
reactions
involved,
its
advantages
potential
applications
specific
An
updated
also
given
studies
reporting
ability
to
couple
extracellular
transfer
insoluble
acceptors;
particularly
iron,
carbon-based
materials
electrodes
in
bioelectrochemical
systems
(BES).
The
latter,
referred
as
anodic
anammox,
promising
strategy
combine
wastewater
bioelectricity
production,
which
discussed
here
terms
efficiency,
economic
feasibility,
energetic
aspects.
Therefore,
information
provided
this
relevant
future
applications.
