Astrobiology,
Journal Year:
2023,
Volume and Issue:
23(5), P. 513 - 535
Published: March 21, 2023
Jezero
Crater
on
Mars
is
a
paleolacustrine
environment
where
Mg-carbonates
may
host
evidence
of
ancient
life.
To
elucidate
the
environmental
and
mineralogical
controls
biosignature
preservation,
we
examined
samples
from
five
terrestrial
analogs:
Lake
Salda
(Turkey),
Alchichica
(Mexico),
Qinghai-Tibetan
Plateau
(China),
Mg-carbonate
playas
(British
Columbia,
Canada),
mine
with
fine-grained
ultramafic
tailings
(Yukon,
Canada).
The
compositions
varied,
yet
were
often
dominated
by
either
aragonite
(CaCO3)
or
hydromagnesite
[Mg5(CO3)4(OH)2·4H2O].
Aragonite-rich
Alchichica,
playas,
contained
an
abundance
entombed
microbial
biomass,
including
organic
structures
that
resembled
cells,
whereas
hydromagnesite-rich
devoid
microfossils.
Aragonite
precipitates
subaqueously
microbes
thrive,
thereby
increasing
likelihood
biomass
entombment,
while
hydrated
typically
form
evaporation
in
subaerial
settings
biofilms
are
less
prolific.
Magnesite
(MgCO3),
most
stable
Mg-carbonate,
forms
extremely
slowly,
which
limit
capture
biosignatures.
Hydrated
prone
to
transformation
via
coupled
dissolution-precipitation
reactions
expose
biosignatures
degradation.
Although
abundant,
commonly
found
environments
better
medium
for
preservation
due
its
fast
precipitation
rates
relative
stability,
as
well
tendency
lithify.
Consequently,
propose
be
considered
valuable
exploration
target
Mars.
Scientific Reports,
Journal Year:
2025,
Volume and Issue:
15(1)
Published: Jan. 2, 2025
Abstract
Microbial
impacts
on
early
carbonate
diagenesis,
particularly
the
formation
of
Mg-carbonates
at
low
temperatures,
have
long
eluded
scientists.
Our
breakthrough
laboratory
experiments
with
two
species
halophilic
aerobic
bacteria
and
marine
grains
reveal
that
these
created
a
distinctive
protodolomite
(disordered
dolomite)
rim
around
grains.
Scanning
Electron
Microscopy
(SEM)
X-ray
Diffraction
(XRD)
confirmed
formation,
while
solid-state
nuclear
magnetic
resonance
(NMR)
revealed
bacterial
interactions
carboxylated
organic
matter,
such
as
extracellular
polymeric
substances
(EPS).
We
observed
significant
carbon
isotope
fractionation
(average
δ
13
C
=
11.3‰)
notable
changes
in
Mg/Ca
ratios
throughout
experiments.
Initial
medium
was
−
18‰,
sterile
sediments
were
2‰
(n
12),
bacterial-altered
6.8‰
final
4.7‰.
These
results
highlight
role
driving
sequestration
into
Mg-rich
carbonates
demonstrate
utility
NMR
tool
for
detecting
microbial
biosignatures.
This
has
implications
understanding
diagenesis
(dissolution
reprecipitation),
climate
science,
extraterrestrial
research.
Environmental Microbiology,
Journal Year:
2024,
Volume and Issue:
26(2)
Published: Jan. 12, 2024
Abstract
Micritization
is
an
early
diagenetic
process
that
gradually
alters
primary
carbonate
sediment
grains
through
cycles
of
dissolution
and
reprecipitation
microcrystalline
calcite
(micrite).
Typically
observed
in
modern
shallow
marine
environments,
micritic
textures
have
been
recognized
as
a
vital
component
storage
flow
hydrocarbon
reservoirs,
attracting
scientific
economic
interests.
Due
to
their
endolithic
activity
the
ability
promote
nucleation
crystals,
microorganisms
progressively
shown
be
key
players
micritization,
placing
this
at
boundary
between
geological
biological
realms.
However,
published
research
mainly
based
on
geochemical
perspectives,
overlooking
ecological
complexity
microbial
communities
micritized
sediments.
In
paper,
we
summarize
state‐of‐the‐art
gaps
micritization
from
ecology
perspective.
Since
growing
body
literature
successfully
applies
vitro
situ
‘fishing’
strategies
unveil
elusive
expand
our
knowledge
diversity,
encourage
application
study
micritization.
By
employing
these
research,
advocate
promoting
interdisciplinary
approach/perspective
identify
understand
overlooked/neglected
pathways
governing
phenomenon
ecology/dynamics,
reshaping
comprehension
process.
Fuels,
Journal Year:
2024,
Volume and Issue:
5(3), P. 394 - 438
Published: Aug. 27, 2024
This
comprehensive
review
investigates
the
potential
of
cyanobacteria,
particularly
nitrogen-fixing
strains,
in
addressing
global
challenges
pertaining
to
plastic
pollution
and
carbon
emissions.
By
analyzing
distinctive
characteristics
including
their
minimal
growth
requirements,
high
photosynthetic
efficiency,
rapid
rates,
this
study
elucidates
crucial
role
transforming
sequestration,
biofuel
generation,
biodegradable
production.
The
investigation
emphasizes
cyanobacteria’s
efficiency
photosynthesis,
positioning
them
as
optimal
candidates
for
cost-effective
bioplastic
production
with
minimized
land
usage.
Furthermore,
explores
unconventional
yet
promising
utilization
biodiesel
production,
mitigating
environmental
concerns
such
sulfur
emissions
presence
aromatic
hydrocarbons.
resulting
exhibits
significant
combustion
potential,
establishing
cyanobacteria
a
viable
option
sustainable
Through
assessment
both
achievements
encountered
during
commercialization
process,
offers
valuable
insights
into
diverse
contributions
cyanobacteria.
Its
objective
is
provide
guidance
researchers,
policymakers,
industries
interested
harnessing
bio-inspired
approaches
structural
applications,
thereby
advancing
efforts
towards
environmentally
conscious
Construction and Building Materials,
Journal Year:
2024,
Volume and Issue:
434, P. 136735 - 136735
Published: May 27, 2024
This
study
evaluated
the
feasibility
and
efficiency
of
stabilizing
washed
recycled
sand
(RS)
derived
from
construction
demolition
wastes
when
treated
by
soybean-based
enzyme-induced
carbonate
precipitation
(EICP),
cured
at
a
low
temperature
4
°C.
Two
types
RS
were
studied,
being
fine
(FRS)
coarse
(CRS).
Urease
extracted
soybeans
was
used
to
catalyze
urea
hydrolysis
reaction,
which
led
calcium
carbonate,
acts
as
soil
binder.
Such
low-temperature
curing
condition
found
effectively
minimize
surface
clogging
same
treatment
cycles
compared
room-temperature
due
comparatively
urease
activity.
The
excess
amount
CaCO3
precipitated
on
block
effective
EICP
solution
flowing
through
sample
did
not
contribute
strength
improvement.
unconfined
compressive
(UCS)
results
CRS
depicted
slight
reduction
curing,
but
improvement
in
bio-clogging
indicated
potential
involving
extra
could
further
develop
strength.
SEM,
EDS
XRD
analyses
established
existence
biocement
gel
triggered
soybean-extracted
temperatures
within
both
FRS
particles.
As
such,
be
an
green
binder
for
terms
noticeable
effect,
hence
suitable
geotechnical
fill
material
ground
works.
Biogeochemistry,
Journal Year:
2025,
Volume and Issue:
168(1)
Published: Jan. 15, 2025
Blue
carbon
represents
the
organic
retained
in
marine
coastal
ecosystems.
Sabkhas
(an
Arabic
for
"mudflats"),
formed
tidal
environments
under
arid
conditions,
have
been
proposed
to
be
capable
of
sequestrating.
Despite
growing
understanding
critical
role
blue
ecosystems,
there
is
a
current
dispute
about
whether
sabkhas
around
Persian
Gulf
can
contribute
retention
as
ecosystem.
The
arguments
often
lack
data
on
contributor,
inorganic
form
carbonates,
which
drive
net
exchange
with
atmosphere.
In
this
study
we
inventory
and
capacity
two
contrasting
Qatar
Peninsula:
carbonaceous
Dohat
Faishakh
siliciclastic
Khor
Al-Adaid.
differences
stock
between
sabkhas,
sabkha
has
higher
(37.17
±
0.81
Mg
Corg
ha-1)
than
it
Al-Adaid
(13.75
0.38
0.
44
m
sediment
depth,
similar
those
reported
mangroves
salt
marshes.
Notably,
calculated
CO2
sequestration
indicated
that
both
evade
into
Thus,
carbonate
formation
negated
accumulation
sabkha.
Consequently,
proper
evaluation
ecosystem,
an
analysis,
especially
formation,
inevitable.
Considering
only
may
ay
overestimate
capacity.
online
version
contains
supplementary
material
available
at
10.1007/s10533-024-01204-5.
