International Materials Reviews,
Journal Year:
2014,
Volume and Issue:
59(7), P. 384 - 393
Published: Aug. 22, 2014
Identification
of
any
mechanism
for
microbiologically
influenced
corrosion
(MIC)
requires
an
understanding
the
specificity
metal/microbe/electrolyte
interactions.
Recent
advancements
in
our
MIC
are
related
to
recognition
implications
this
specificity.
For
example,
under
some
circumstances,
nutrients
can
accelerate
rates
corrosion.
In
other
cases
oxyanions
inhibit
localised
environments
absence
oxidisable
carbon
force
a
shift
electron
donor
and
may
result
more
aggressive
than
presence
carbon.
Non-corrosive
biofilms
become
corrosive
with
subtle
changes
environment,
e.g.,
addition
shuttle
compounds.
The
list
donors
acceptors
has
been
expanded
metabolic
flexibility
that
demonstrated
microorganisms.
research
on
microbial
fuel
cells
batteries
added
microbial/metal
Applied and Environmental Microbiology,
Journal Year:
2013,
Volume and Issue:
80(4), P. 1226 - 1236
Published: Dec. 7, 2013
About
a
century
ago,
researchers
first
recognized
connection
between
the
activity
of
environmental
microorganisms
and
cases
anaerobic
iron
corrosion.
Since
then,
such
microbially
influenced
corrosion
(MIC)
has
gained
prominence
its
technical
economic
implications
are
now
widely
recognized.
Under
anoxic
conditions
(e.g.,
in
oil
gas
pipelines),
sulfate-reducing
bacteria
(SRB)
commonly
considered
main
culprits
MIC.
This
perception
largely
stems
from
three
recurrent
observations.
First,
sulfate-rich
environments
seawater)
particularly
corrosive.
Second,
SRB
their
characteristic
product
sulfide
ubiquitously
associated
with
damage,
third,
no
other
physiological
group
produces
comparably
severe
damage
laboratory-grown
pure
cultures.
However,
there
remain
many
open
questions
as
to
underlying
mechanisms
relative
contributions
On
one
hand,
constructions
indirectly
through
corrosive
chemical
agent,
hydrogen
sulfide,
formed
by
organisms
dissimilatory
sulfate
reduction
organic
compounds
or
("chemical
corrosion";
CMIC).
certain
can
also
attack
via
withdrawal
electrons
("electrical
EMIC),
viz.,
directly
metabolic
coupling.
Corrosion
is
typically
formation
sulfides
(FeS)
which,
paradoxically,
may
reduce
some
while
they
increase
it
others.
brief
review
traces
historical
twists
SRB-induced
corrosion,
considering
presently
most
plausible
explanations
well
possible
early
misconceptions
understanding
anoxic,
environments.
Direct,
mediator-free
transfer
of
electrons
between
a
microbial
cell
and
solid
phase
in
its
surrounding
environment
has
been
suggested
to
be
widespread
ecologically
significant
process.
The
high
rates
electron
uptake
observed
during
microbially
influenced
corrosion
iron
[Fe(0)]
electrosynthesis
have
considered
support
for
direct
these
processes.
However,
the
underlying
molecular
mechanisms
are
unknown.
We
investigated
characteristics
Fe(0)-corroding
electromethanogenic
archaeon
Methanococcus
maripaludis
discovered
that
free,
surface-associated
redox
enzymes,
such
as
hydrogenases
presumably
formate
dehydrogenases,
sufficient
mediate
an
apparent
uptake.
In
genetic
biochemical
experiments,
we
showed
which
released
from
cells
routine
culturing,
catalyze
formation
H2
or
when
sorbed
appropriate
redox-active
surface.
These
low-molecular-weight
products
rapidly
consumed
by
M.
present,
thereby
preventing
their
accumulation
any
appreciable
even
detectable
level.
Rates
cell-free
spent
culture
medium
were
explain
methane
Fe(0)
cathode-derived
wild-type
well
mutant
strain
carrying
deletions
all
catabolic
hydrogenases.
Our
data
collectively
show
cell-derived
free
enzymes
can
mimic
extracellular
may
represent
important
but
so
far
overlooked
mechanism
biological
transfer.The
intriguing
trait
some
organisms
engage
is
thought
nature.
Consequently,
into
surfaces
assumed
impact
not
only
on
fundamental
biogeochemical
processes
also
applied
bioelectrochemical
systems,
biocorrosion.
This
study
provides
simple
mechanistic
explanation
frequently
fast
kinetics
microbiological
systems
without
transfer:
interact
with
cathodic
intermediates
cells.
likely
plays
role
various
reactions
environment.
