Mechanism of oxidation of carbon monoxide by bacteria

Vol. 83, No. 4, 1978

BIOCHEMICAL

AND BIOPHYSICAL

RESEARCH COMMUNICATIONS

August29,1978

Pages 1584-1587

MECHANISM OF OXIDATION

OF CARBON MONOXIDE BY BACTERIA

S. Kirkconnell

and G. D. Hegeman

Department of Biology, Indiana University Bloomington, Indiana 47401

Received

July

lo,1978

SUMMARY--Double label experiments were performed employing 13C0 and eitherzl*O or 1802 in the presence of a CO utilizing bacterium. CO2 generated was trapped and m/e ratios 47/45 showed that the second oxygen atom in the oxidation of CO to CO2 by this bacterium comes neither from O2 nor H20. Introduction Kistner expense second

(1)

provided

of carbon oxygen

CO oxidizers

atom for

in

such as:

described

here

is

utilitarian

by separative

that

will

grow

atmosphere physiological detail

at the

test

hydration

expense

through

characteristics

This

of formate hydrogen

of this

by a hypothetical

that

molecular

oxygen

atom during

source

bacterium

of carbon

and

was isolated

from

Gram negative,non-motile

but will

not

bacteria.

bacterium

1584

the

CO utilizing

bacterium

and is a short,

publication.

0 I978 by Academic Press, Inc. of reproduction in any form reserved.

second

of CO as sole

with

The experiments

An aerobic

0006-291X/78/0834-1584$01.00/0 Copyright All rights

(2),

of the

studies.

used to grow

of the

and utilitarian

followed

of the hypothesis

donor

expense

in these

at the

in a future

for

of CO to CO2.

enrichment

typically

gratuitous

at the

source

has been studied

CO oxidation

the potential

was employed

soil

as to the

CO t Hz0 + HCOOH + CO;! + 2H.

oxidation

of growth

test

a direct

growth

on H20 or O2 (2,3,4,5,6,7,8,9).

in CO oxidation

utilitarian

report

or water

of microbial

in both

exclusively

an indirect

mechanism

energy

Speculation

of formate

dehydrogenation

capable

(CO).

CO oxidation

has focused

hope of providing

the

proof

monoxide

The intermediacy

oxygen

the first

will

grow Other

under

rod an

cultural

be described

and in

BIOCHEMICAL

Vol. 83, No. 4, 1978

AND BIOPHYSICAL

RESEARCH COMMUNICATIONS

Methods 13C0 (Stohler vacuum rack disc

Isotope

constructed

through

which

from

the

expense

of

generated

gas-tight

nitrogen experiment

of Hz I*0

vacuum rack (Precision

liquid

in the

filled

reflect

ratios

system

based

Gases formed

or 1802. sequentially a liquid

through oxygen

permitted

cooled

trap

of water

and minimized

possible

carbonate

possible

confusion

minutes,

CO2 collected

(13C1602)

(referred

produced

in the

sample

Instruments). reservoir

'e0,

was repeated ratios

traps

through

oxygen

and m/e=47 ratios

trap

of the

1585

liquid

design

by

oxygen that

After

was cryogenically

from

: m/e=45 on a CH7 mass

total

CH7, approximately

H,O

eliminates

carbonate.

were measured Estimated

swept

in CO2 with

(13~160180)

H21*0

arrangement

CO2 in the

experimental

exchange

the

followed

This

atoms

reported

by either were

cooled

of oxygen This

into

labelling

the

of

The H2l*O

suspension

to trapping

experiments.

COz-free

Anticipated

slush

as

portion

introduction.

l*O2.

ice

exchange

bottle

the

experiment

cell

and

a locking,

the major

to recirculation.

from

using

1802 : 1602 introduced

bacterial

to as 47/45)

(Varian

l30,

of

in the liquid

to an evacuated

spectrometer

the

at

1802 was

experiments,

1802

to I*02

intermediate.

distilled

from

of stoichiometric

prior

grown

H2180 was added

constituted

For the

prior

resulting

septum

separate

air

two acetone-dry

removal

the

a rubber Corporation).

while

in the

previously

99% enriched)

prior

assumption

medium

Laboratory,

CO,-free

: H21*0 or

25 milliliters/minute.

(Mound

Sampling

once,

was recirculated

disc.

concentrations

on the

rack

a

a fritted

the fritted

vacuum rack.

of H2160

in the

into

above

through

the vacuum rack

different

and containing

minimal

in experiments

was repeated

using

through

in liquid

experiments,

atmosphere

trap

the

total

For the H zl*O

twice

of cells

syringe

9.9% of the

atmosphere

12C0, was introduced

into

tubing

was introduced

pump at approximately

by electrolysis

introduced

the

Bellows

suspension

90% enriched)

6mm. glass

the gaseous

by means of a Metal A dense

Chemicals,

pressure 0.5 milliliters

90

Vol. 83, No. 4, 1978

(STP)

CO2 were

produced

of CO, derived oxidation

BIOCHEMICAL

from

during

was oxidized

(m/e = 44)

than

during

1:5. the

varied

The ratio

to CO2 formed between

Approximately course

RESEARCH COMMUNICATIONS

of each experiment.

of CO (m/e = 45)

reserves

but was in no case lower supplied

the course

the oxidation

of cellular

AND BIOPHYSICAL

by the

experiments,

25% of the

13C0

of each experiment.

Results H,lBO:

Experiments

Anticipated Observed

47/45 47/45

ratio

0.10

ratios

#1 and 82 t 0.003

29.01

'802 :

Experiment

Anticipated Observed

47/45 47/45

ratios

0.23

ratios

Experiment

#l + 0.01

Experiment

2 0.01

0.10

20.01

#2

0.15

(0.01

#3

+ 0.01

-co.01

Discussion These

results

CO to CO, does not equilibrates that

the

either.

its

show that

the second

come from

H,D or any species

oxygen

second

oxygen

with

present

studies

utilitarian

CO oxidation,

and O2 must

be sought.

of water.

is

for

CO oxidation

representative then

atom in the oxidation that

possible

results

directly

from molecular

employed

by the

of a general sources

of

rapidly

The present

atom is not derived

If the mechanism

in the

that

oxygen

other

show

oxygen

bacterium

mechanism

of oxygen

also

used

for than

HP0

Acknowledgements Development funds

supplied

of the mass spectrometry to the Department

National

Science

helpful

discussions

permitting

Foundation of this

the use of his

facilities

of Chemistry,

was made possible Indiana

Grant

GP-32225.

kre thank

work

in progress

and his

facilities.

1586

University,

by

John Hayes for generosity

by

in

Vol. 83, No. 4, 1978

BIOCHEMICAL

AND BIOPHYSICAL RESEARCH COMMUNICATIONS

REFERENCES 1.

Kistner, 443-449.

A.

(1953)

2.

Meyer, Second

3.

Kirkconnell, S. and G.D. Hegeman (1976) Abstracts of the 76th Annual American Society for Microbiology National Meeting, Atlantic City p. 121,157 Published by the American Society for Microbiology.

4.

Kirkconnell, Microbiology,

5.

Thauer, Bioch.

6.

Ferenci,

7.

Uffen,

R.L.

8.

Kluyver 57-70.

, A.J.

9.

Daniel, -132(l)

Fuchs, 1:81126.

0. and H.G. International

Proc.

Kon.

Ned. Akad.

v. Wet.

"Microbial Pushchino

Growth (1977)

Schlegel in Symposium,

S. and G.D. Hegeman (1977) American Indiana Branch Spring Meeting.

R.K., G. Fuchs, -45: 343-349. T.

B. Kaufer,

FEBS Letters PNAS USA

and Schnellen, G.,

Thauer,

4L(l)

3298-3302.

C.G.

(1947)

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for

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Eur.

J.

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R.K.,

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on Cl-Compounds" 95-97.

and U. Schnitker

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(1977)

S.,

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and Zeikus,

Bioch. J.G.

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14

J. Bact.