06 Bioremediation Ta.. - Murdoch University

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)