Author’s
Profile
My
name
is
Tan
Liang
Juin
and
I
am
a
final
year
student
in
Murdoch
University,
majoring
in
Biotechnology
and
Molecular
Genetic
.
My
interest
lies
in
the
beauty
of
our
amazing
world
that
is
able
to
sustain
life
.
I
choose
this
topic
because
a
portion
of
these
widely
used
chlorine
hydrocarbon
are
toxic
and
pose
serious
cause
for
health
and
environment
concerns
.
Some
are
also
known
to
be
quite
stable
in
nature
and
can
be
absorbed
into
fatty
tissues,
such
that
it
can
be
accumulated
up
a
food
chain
resulting
in
biomagnification,
with
us
consuming
the
highest
amounts
of
these
toxic
compounds!
One
relevant
case
is
the
chlorine
hydrocarbon
contamination
of
Orica’s
Botany
Industrial
Park,
which
is
just
in
Sydney
.
It
is
quite
major
and
imagine
the
possibility
of
taking
up
to
30
years
to
remediate
.
Author
: Tan Liang Juin
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Dehalococcoides Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Papers of
Comparision
1.
Role of ''
Dehalococcoides
'' spp. in the
Anaerobic
Transformation of
Hexachlorobenzene
in European Rivers.
Neslihan
Tas
, Miriam H. A. van
Eekert
,
Anke
Wagner, Gosse
Schraa
, Willem
M. de
Vos
and
Hauke
Smidt
(2011)
Role of ''
Dehalococcoides
'' spp. in the
Anaerobic Transformation of
Hexachlorobenzene
in European Rivers.
Applied and
Environmental Microbiology
77
, 4437
-
4445
2.
Molecular Analysis of
Dehalococcoides
16S Ribosomal DNA
from
Chloroethene
-
Contaminated Sites throughout North
America and Europe
Edwin R. Hendrickson, Jo Ann Payne, Roslyn M. Young, Mark G. Starr,
Michael P. Perry, Stephen
Fahnestock
, David E. Ellis & Richard C.
Ebersole
(
2001)
Molecular Analysis of
Dehalococcoides
16S Ribosomal DNA from
Chloroethene
-
Contaminated Sites throughout North America and Europe
.
Applied
and Environmental Microbiology
68
, 485
-
495
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Dehalococcoides Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Exclusive
Summary
Comparison
to
determine
potential
of
Dehalococcoides
spp
for
use
in
bioremediation
of
contaminated
sites
and
underground
water,
by
reductive
dechlorination
of
toxic
chlorine
hydrocarbon
to
hydrocarbon
.
Favourable
to
be
found
widely
in
nature,
dechlorinate
wide
range
of
chlorinated
hydrocarbon
and
tolerant
to
high
concentration
of
chlorinated
hydrocarbons
in
contaminated
sites
.
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Background
1
(
About
Chlorinated
hydrocarbon)
Chlorine
hydrocarbon
are
used
extensively
for
the
production
of
vinyl
chloride,
pesticides,
chlorinated
solvents
for
industrial
usage
and
for
insulation
.
Toxic
compounds
like
carcinogenic
Hexachlorobenzene
(HBC)
and
neurotoxicity
and
endocrine
disrupting
Polychlorinated
Biphenyls
(PCB)
,
are
now
ban
in
countries
due
to
health
and
environmental
concerns
.
HBC
and
PCB
are
quite
resistant
to
aerobic
microbial
degradation,
hence
have
long
half
-
life
and
remains
in
the
environment
for
long
periods,
with
possible
biomagnification
up
the
food
chain
.
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Background
2
(
Dehalococcoides
spp)
Dehalococcoides
spp
are
currently
the
only
few
known
microorganisms
capable
of
carrying
out
the
alternative
route
of
anaerobic
reductive
dechlorination
of
these
compounds
coupled
to
their
growth,
using
hydrogen
as
electron
donor
and
replacing
chlorine
atoms
in
the
chlorine
hydrocarbon
,
till
all
chlorine
atoms
are
replaced
.
(
Neslihan
Tas
,
2011
)
They
are
a
ble
to
carry
out
anaerobic
reductive
dechlorinate
of
chloroethenes
to
the
benign
end
product
of
ethene
is
especially
important
if
they
are
to
be
used
for
bioremediation
of
contaminated
land
and
underground
water
.
(
Wei
-
Qin
Zhuang
,
2011
)
.
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Summary
1
Role
of
''
Dehalococcoides
''
spp
.
in
the
Anaerobic
Transformation
of
Hexachlorobenzene
in
European
Rivers
(
Neslihan
Tas
,
2011
)
Sample
collection
River
sediments
and
water
where
obtained
from
Four
E
uropean
rivers
Floodplain
soil
where
also
obtain
from
Elbe
River
Methods
Samples
were
either
with
known
history
of
HCB
contamination,
O
r
samples
were
additionally
added
with
chlorinated
aliphatic
compounds
Samples
were
added
with
lactate
as
electron
donor
Samples
were
store
in
an
anaerobic
environment
Samples
were
Incubated
in
the
dark
at
30
degree
Celsius
Experiments
where
triplicate
for
purpose
of
control
(no
sediments)
and
Abiotic
sediments
Microcosm
were
tested
in
intervals
of
7
-
10
days
for
dechlorination
(
establish
within
2
-
4
wks)
Temperature
effect
were
also
being
test
by
collecting
samples
of
river
sediment
over
5
months
that
was
subjected
to
temperature
change
of
4
-
37
degree
Celsius
Analytical
method
Gas
chromatography
was
used
to
measure
mass
of
chlorinated
benzene
Fast
DNASpinKit
was
used
for
DNA
isolation
Cloning,
sequencing
and
quantitative
PCR
was
done
to
measure
abundance
of
Dehalococcoides
spp
Terminal
restriction
Fragment
length
polymorphism
(T
-
RFLF)
was
used
to
detect
reductive
dehalogenation
genes
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Summary
2
Role
of
''
Dehalococcoides
''
spp
.
in
the
Anaerobic
Transformation
of
Hexachlorobenzene
in
European
Rivers
(
Neslihan
Tas
,
2011
)
Results
and
Discussion
12
out
of
15
sediments
were
able
to
dechlorinate
HCB
to
lower
chlorinated
benzene,
while
HCB
was
not
degraded
in
abiotic
or
autoclaved
controls
.
This
shows
microbes
were
responsible
for
the
degrading
of
HCB
and
that
they
are
found
in
quite
wide
areas
.
1
sediments
that
had
no
dechlorination
where
found
to
contain
high
concentration
of
heavy
metal
.
This
show
possible
hindrance
of
dechlorination
by
heavy
metal
.
Very
low
levels
of
penta
or
tetrachlorobenzene
were
dedected
,
while
Monochlorobenzene
was
not
detected
at
all
throughout
the
experiment
.
At
end
of
5
months,
Trichlorobenzene
and
Dichlorobenzene
was
detected
.
This
show
only
partial
dechlorination
of
HCB
is
achieved
.
Dehalococcoides
was
detected
in
most
sample
with
dechlorination
,
showing
its
relation
to
dechlorination
of
HCB
.
In
laboratory
samples,
those
with
added
lactate
start
having
dechlorination
after
10
day,
while
no
lactate
started
only
after
30
days
lag
.
No
dechlorination
observed
in
river
water
samples
without
sediment
.
Possible
biostimulation
using
lactate
.
Temperature
studies
shows
dechlorination
can
occur
at
low
temperatures
but
will
require
longer
time
.
Conclusion
There
is
potential
for
in
-
situ
biodegradation
of
HCB,
but
more
information
on
HCB
is
required
for
effective
biodegradation
of
HCB
.
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Summary
1
Molecular
Analysis
of
Dehalococcoides
16
S
Ribosomal
DNA
from
Chloroethene
-
Contaminated
Sites
throughout
North
America
and
Europe
(Edwin
R,
2001
)
Sample
collection
Soil
and
samples
were
obtain
from
depths
ranging
from
3
-
25
m
Groundwater
samples
were
also
collected
Methods
Microcosm
were
prepared
with
minimal
salt
medium
and
0
.
05
%
yeast
extract
Duplicated
microcosms
were
made
and
sterilized
as
control
Samples
stored
in
anaerobic
conditions
Samples
were
incubated
at
22
Degree
Celsius
Testing
was
done
twice
a
week
for
180
days
.
Analysis
Method
Gas
chromatography
was
use
to
test
for
Chloroethene
and
ethane
contents
FastDNA
SPIN
kit
was
used
for
DNA
extraction
of
soil
sample
PCR
assay
was
used
to
identify
Dehalococcoides
groups
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Summary
2
Molecular
Analysis
of
Dehalococcoides
16
S
Ribosomal
DNA
from
Chloroethene
-
Contaminated
Sites
throughout
North
America
and
Europe
(Edwin
R,
2001
)
Results
and
Discussion
Dehalococcoides
were
found
in
samples,
whereby
PCE
was
fully
dechlorinated
to
ethene
,
shows
ability
of
Dehalococcoides
for
fulll
-
dechlorination
.
Partial
dechlorination
of
PCE
to
TCE
and
cDCE
was
found
in
aerobic
oxidized
environment,
showing
anaerobic
is
very
essential
for
complete
dechlorination
.
Dechlorination
was
found
to
occur
in
a
wide
range
of
climatic
zones
(subtropical
to
temperate),
due
to
the
large
-
scale
area
in
which
samples
from
obtained
for
the
experiment
.
Groundwater
samples
shows
possibility
of
full
dechlorination
of
PCE,
provided
conditions
are
anaerobic
and
reduced
.
Conclusion
Dehalococcoides
have
the
potential
to
carry
out
full
dechlorination
of
Chloroethene
,
however
these
activates
are
found
to
be
site
specific
.
They
are
found
to
also
exist
in
a
wide
range
of
climatic
zone
and
areas
.
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Comparison
of
papers
Paper 1
Paper 2
Area Scale with
Dehalococcoides
Europe
(Smaller scale for climatic
and
geologial
aspect)
North America
& Europe
(Wider scale for climatic
and
geologial
aspect)
Samples collected
Sediments, soil
and river
-
water
Soil and Ground
water
Substrate
dechlorinated
HCB
to DCB
(Partial)
PCE
to
Ethene
(Complete)
Temperature
Incubate at 22degree
celcius
Incubation at
30degree
celcius
Duration
5
months
6months
Methods
Both
h
ave
controlled experiments
Both uses anaerobic incubation
Both have environmental and in
-
lab testing (Microcosm)
Both uses PCR assay
Both uses Fast
DNASpinKit
Both
uses
Gas chromatography
Both
tested effects of temperature range
Conclusion
Both
complements and support
Dehalococcoides
as
potential organism for use in
dechlorination
of HCB and
PCE in anaerobic conditions.
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Critical
Comments
Combination
of
works
shows
additive
evidences
of
Behalococcoides
existence
in
wide
spread
areas
of
Europe
and
North
America
.
This
is
very
relevant
for
Bioremediation
as
it
provides
opportunities
for
further
research
into
Biostimulation
(
Bioremedition
)
of
local
population
of
Behaloccoides
to
carry
out
more
effective
dechlorination
of
HCB
and
PCE
.
More
research
can
also
be
done
to
determine
the
optimal
conditions
of
Dehalococcoides
to
carry
out
reductive
dechlorination
and
if
any
additional
substrate
can
be
added
to
catalyse
the
activity
.
Both
works
seems
to
be
of
good
quality
as
they
take
into
accounts
control
setups
for
the
experiments
and
temperature
effects
on
the
rate
of
dechlorination
.
Thou
the
first
test
it
using
natural
temperature
and
the
latter
did
so
in
a
lab
setting
.
However,
no
research
was
done
to
determine
if
the
intermediates
produced
from
dechlorination
of
the
HCB
and
PCE,
were
less
toxic
then
the
original
compounds
.
If
these
intermediates
are
even
more
harmful
then
the
original
compounds,
the
partial
dechlorination
will
result
more
harmful
effect
to
the
environments
.
Unless,
full
-
dechlorination
can
be
ensured
.
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
Reference
Wei
-
Qin Zhuang, Shan Yi, Xueyang Feng, Stephen H
.
Zinder, Yinjie J.
Tang and Lisa Alvarez
-
Cohen(2011)
Selective Utilization of Exogenous
Amino Acids by
Dehalococcoides ethenogenes Strain 195
and Its Effects on
Growth and Dechlorination Activity.
Applied and Environmental
Microbiology
77
, 7797
-
7803
Neslihan Tas, Miriam H. A. van Eekert, Anke Wagner, Gosse Schraa,
Willem M. de Vos and Hauke Smidt
(2011)
Tracking Functional Guilds: “Dehalococcoides” spp. in European
River Basins Contaminated with Hexachlorobenzene
.
Applied and
Environmental Microbiology
75
, 4696
-
4704
Lorenz Adrian, Vlasta Dudková, Katarina Demnerová and Donna L.
Bedard (2009)
“Dehalococcoides” sp. Strain CBDB1 Extensively
Dechlorinates the Commercial Polychlorinated Biphenyl Mixture Aroclor
1260.
Applied and Environmental Microbiology
75
, 4516
-
4524
Dehalococcoides
Abundance and Role in
Degradation of Chlorinated Hydrocarbons
Home
Papers of Comparison
Exclusive Summary
Background 1
Summary 2
Summary 1
Critical comments
Comparison of papers
References
Background 2
(Neslihan
Tas ,2011)
Summary 2
Summary 1
(
Edwin R
,2001)
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