Frontiers in Microbiology,
Journal Year:
2020,
Volume and Issue:
11
Published: Feb. 12, 2020
Biodegradation
of
synthetic
polymers,
in
particular
polyethylene
terephthalate
(PET),
is
great
importance,
since
environmental
pollution
with
PET
and
other
plastics
has
become
a
severe
global
problem.
Here,
we
report
on
the
polyester
degrading
ability
novel
carboxylic
ester
hydrolase
identified
genome
marine
hydrocarbonoclastic
bacterium
Pseudomonas
aestusnigri
VGXO14
T
.
The
enzyme,
designated
PE-H,
belongs
to
type
IIa
family
hydrolytic
enzymes
as
indicated
by
amino
acid
sequence
homology.
It
was
produced
Escherichia
coli,
purified
its
crystal
structure
solved
at
1.09
Å
resolution
representing
first
enzyme.
shows
typical
α/β-hydrolase
fold
high
structural
homology
known
hydrolases.
hydrolysis
detected
30°C
amorphous
film
(PETa),
but
not
from
commercial
bottle
(PETb).
A
rational
mutagenesis
study
improve
potential
PE-H
yielded
variant
(Y250S)
which
showed
improved
activity,
ultimately
also
allowing
PETb.
this
1.35
allowed
rationalize
improvement
enzymatic
activity.
oligomer
binding
model
proposed
molecular
docking
computations.
Our
results
indicate
significant
P.
for
degradation.
Proceedings of the National Academy of Sciences,
Journal Year:
2018,
Volume and Issue:
115(19)
Published: April 17, 2018
Significance
Synthetic
polymers
are
ubiquitous
in
the
modern
world
but
pose
a
global
environmental
problem.
While
plastics
such
as
poly(ethylene
terephthalate)
(PET)
highly
versatile,
their
resistance
to
natural
degradation
presents
serious,
growing
risk
fauna
and
flora,
particularly
marine
environments.
Here,
we
have
characterized
3D
structure
of
newly
discovered
enzyme
that
can
digest
crystalline
PET,
primary
material
used
manufacture
single-use
plastic
beverage
bottles,
some
clothing,
carpets.
We
engineer
this
for
improved
PET
capacity
further
demonstrate
it
also
degrade
an
important
replacement,
polyethylene-2,5-furandicarboxylate,
providing
new
opportunities
biobased
recycling.
ACS Catalysis,
Journal Year:
2019,
Volume and Issue:
9(5), P. 4089 - 4105
Published: April 8, 2019
Most
petroleum-derived
plastics,
as
exemplified
by
poly(ethylene
terephthalate)
(PET),
are
chemically
inactive
and
highly
resistant
to
microbial
attack.
The
accumulation
of
plastic
waste
results
in
environmental
pollution
threatens
ecosystems,
referred
the
"microplastic
issue".
Recently,
PET
hydrolytic
enzymes
(PHEs)
have
been
identified
we
reported
degradation
a
consortium
its
bacterial
resident,
Ideonella
sakaiensis.
Bioremediation
may
thus
provide
an
alternative
solution
recycling
waste.
mechanism
into
benign
monomers
hydrolase
mono(2-hydroxyethyl)
terephthalic
acid
(MHET)
from
I.
sakaiensis
has
elucidated;
nevertheless,
biodegradation
require
additional
development
for
commercialization
owing
low
catalytic
activity
these
enzymes.
Here,
introduce
degrading
microorganisms
involved,
along
with
evolution
PHEs
address
issues
that
hamper
enzymatic
degradation.
Potential
applications
also
discussed.
Applied Microbiology and Biotechnology,
Journal Year:
2019,
Volume and Issue:
103(11), P. 4253 - 4268
Published: April 8, 2019
Enzymatic
hydrolysis
of
polyethylene
terephthalate
(PET)
has
been
the
subject
extensive
previous
research
that
can
be
grouped
into
two
categories,
viz.
enzymatic
surface
modification
polyester
fibers
and
management
PET
waste
by
hydrolysis.
Different
enzymes
with
rather
specific
properties
are
required
for
these
processes.
is
possible
several
hydrolases,
such
as
lipases,
carboxylesterases,
cutinases,
proteases.
These
should
designated
surface–modifying
not
degrade
building
blocks
but
hydrolyze
polymer
chain
so
intensity
weakened.
Conversely,
requires
substantial
degradation
PET;
therefore,
only
a
limited
number
cutinases
have
recognized
hydrolases
since
first
hydrolase
was
discovered
Müller
et
al.
(Macromol
Rapid
Commun
26:1400–1405,
2005).
Here,
we
introduce
current
knowledge
on
focus
key
class
enzymes,
pertaining
to
definition
requirements
hydrolysis,
structural
analyses
reaction
mechanisms.
This
review
gives
deep
insight
basis
dynamics
based
recent
progress
in
X-ray
crystallography.
Based
accumulated
date,
discuss
potential
applications,
designing
stream
management.
ACS Catalysis,
Journal Year:
2019,
Volume and Issue:
9(4), P. 3519 - 3526
Published: March 11, 2019
Widespread
utilization
of
polyethylene
terephthalate
(PET)
has
caused
a
variety
environmental
and
health
problems;
thus,
the
enzymatic
degradation
PET
can
be
promising
solution.
Although
PETase
from
Ideonalla
sakaiensis
(IsPETase)
been
reported
to
have
highest
activity
under
mild
conditions
all
PET-degrading
enzymes
date,
its
low
thermal
stability
limits
ability
for
efficient
practical
PET.
Using
structural
information
on
IsPETase,
we
developed
rational
protein
engineering
strategy
using
several
IsPETase
variants
that
were
screened
high
improve
activity.
In
particular,
IsPETaseS121E/D186H/R280A
variant,
which
was
designed
stabilized
β6-β7
connecting
loop
extended
subsite
IIc,
had
Tm
value
increased
by
8.81
°C
enhanced
14-fold
at
40
in
comparison
with
IsPETaseWT.
The
modifications
further
verified
through
structure
determination
variants,
confirmed
heat-inactivation
experiment.
proposed
represent
an
important
advancement
achieving
complete
biodegradation
conditions.
