8/12/2019 Artculo Biognesis Marte

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Volume 7

2003

pp 2382395 EUROPE

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PH. D. R. G. CUERO

Life On MarsBiogenesis Studies Using MartianSimulant Soil and Electrosensors

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Life On MarsBiogenesis Studies Using MartianSimulant Soil and Electrosensors

R. G. Cuero

Mars and Earth are part of the inner plan-

ets (nearest the Sun) of the Solar System,

and they are made of rocks (silicates) with

iron rich cores [1]. Therefore, perhaps the

explorations to neighboring planets such

as Mars and Venus will help us to under-

stand better the origin of life on earth and

what life really is as a physical-chemical

and biological system. Molecular paleon-tology tells us how life on Earth was at

certain point of history under oxidation

conditions, but it does not tell us how life

began or how the process from reduction

to oxidation conditions of present life hap-

pened. But Mars is still under a reduced

condition as compared to earth and thus

understanding of life on Mars may require

a revised understanding of Life. Also, it

has been reported that ultrafine-grained

magnetite in a Martian meteorite exhib-

ited similarities to biogenic magnetite pro-

duced on Earth [2]. However, Mars mayrepresent what planet Earth was or what

Earth would become.

Recent explorations to Mars have par-

tially demonstrated some of the atmos-

pheric composition of the planet such as

lower oxygen levels as compared to cur-

rent levels on Earth. Mars has a thin or

lower pressure atmosphere with higher

CO2 (95 %) and lower Nitrogen (2.7 %), as

compared to Earth, which has higher Ni-

trogen (78 %) and O2 (21 %). Although the

full picture of how Earths atmosphere

evolved remains unresolved the early at-mosphere should have been dry. Thus

precluding the possibility of an oxygenic

prebiotic atmosphere caused by photo

dissociation of water vapor followed by

escape of hydrogen to space [3]. These

early conditions of Earth seem to be simi-

lar to the current condition on Mars, ac-

cording to some reports from Martian ex-

plorations [1]. Similarly, explorations

and/or studies of Mars through remote

sensing confirm the highly reduced state

of Mars and its high iron content, thus

suggesting a soil with a high ferromagnet-ism, although unlike Earth, no planetwide

magnetic field has been found on Mars

[1]. Also, great presence of ultraviolet

light radiation has been detected on Mars.

Geological and microbiological reports

suggest that reduction of Fe (III) was a

very early form of respiration on Earth,

and geochemists have also proposed that

high levels of ultraviolet radiation pro-

duced abundant Fe (III) oxides and H2 on

the anoxic, prebiotic Earth [4]. Thus, sug-

gesting more evidences of the similarities

between early conditions of Earth and thecurrent conditions of Mars.

However, presence of life on extrater-

restrial planets such as Mars, has been

difficult to demonstrate during the differ-

ent explorations, because of the lack of understanding of the geo-

biological electrokinetic interaction at

the molecular level, the lack of sensitive devices at the mi-

cro and nano levels to detect lower le-

vels of iron-reducing microorganisms

especially autotrophic (use metals as

electron acceptors for energy biosyn-thesis) which are more likely to be the

dominant and not the heterotrophic

(carbon base molecular structure)

which are the dominant on Earth.

Results from cur-

rent laboratory ex-

perimental research

on biogenesis of

Mars, carried out atPrairie View A&M

University (PVAMU),

Texas, and funded

by NASA-JSC-Hous-

ton (in collabora-

tion with Dr D.

Mckay), are sug-

gesting that presence of any form of

microscopic life on Mars depends not

only on water, but also on the interac-

tion of other equally essential factors

such as oxidation-reduction of iron,

ferromagnetic fields, and ultraviolet

radiation.

R. G. Cuero

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and also because of the lack of an

analog matrix to simulate the initial

highly reducing conditions of the soil

in Earth as well as in the present con-

ditions of Mars.

Oxidation-reduction of iron has been sug-

gested as one of the mechanisms for au-

totrophic bacterial metabolism on earlyEarth, and UV radiation as a mediator of

this iron cycle [5] (Fig.1). On the contrary,

most of the approaches and/or techniques

to study life on Mars has been based on

life on Earth, for heterotrophic microor-

ganisms. However, the interacting effect

of iron-oxidation reduction, UV light, and

magnetism on biogenesis has not been de-

termined.

Scientists at PVAMU have now been

able to demonstrate the growth of au-

totrophic iron-depending bacteria in a

highly iron content Martian simu-

lated soil. Mea-

surements were

made under ul-

traviolet radia-

tion, using a series

of electrosensors,

thus establishing a

measurement and

control interface

(MCI) at different mil-

Amperes and mil-Volt-

age, which is also linked to a

computer intelligent system. Dif-

ferent time course experiments were setup under laboratory conditions, and a se-

ries of parameters including electro-con-

ductivity, redox potential and electron

emission, oxygen levels using fiber optic

sensors through an infra-red spectropho-

tometer, pH, iron (Fe II/III) concentration

using a voltmeter, and soil culture para-

magnetism, were measured. These re-

sults were correlated with bacterial

growth through spectrophotometer, agar

colonies forming units, and through elec-

tron microscopy. Formation of bacterial

biofilm and expression of DNA/RNA werealso correlated.

Results from this laboratory, clearly

showed the marked interactive effect of

UV light, the constant oxidation-reduc-

tion, and paramagnetism on the growth of

the autotrophic bacteria in the Martian

simulated soil (Figs. 1, 2). The level of UV

intensity seems to have been enough to

stimulate growth of the autotrophic bacte-

ria in the Martian simulated soil with high

concentration of iron. The increased bac-

terial growth was observed through opti-

cal density, agar CFU, and by the forma-tion of a thick biofilm underneath of the

Martian simulated soil bacterial culture,

and by electron microscopy. The results

correlate well with the emission of elec-

trons. The ability of iron in

absorbing UV light and even

the oxidative UV photolysis,

has been demonstrated [6].

Both the level of iron content

and UV radiation are high on

Mars, thus the present re-

sults suggest the positive ef-

fect of UV light on iron oxi-dation-reduction in relation

with presence of microscopic

autotrophic life in Martian

soil. The formation of the

bacterial biofilm underneath

of the Martian simulated

soil, also suggests a possible

magnetoctatic effect of the

Martian simulated soil on

the cell magnetic dipole. This

magnetotactic effect can

be correlated with the

higher ferromagnetic read-

ing (9001300 CGS) that

we have found in the Mart-

ian simulated soil [7]. Also,

the formation of the bacter-

ial biofilm under the simu-

lated soil can be due to the

effect of the UV light inten-

sity, especially after the oxi-

dation-reduction of the iron.

The laboratory results

showed a correlation be-

tween higher electron emission and redox

potential from the Martian soil culture

with higher bacterial growth and biofilmformation, especially under UV light, as

compared to control under no UV light ex-

posure. Therefore, these results are sug-

gesting that perhaps the mechanism of

survival of any microscopic life in the soil

of Mars, follows a chemiosmotic circuit,

under an anodic and cathiodic reactions,

connected one half of the circuit by the

electron transport chain [8]. Current ex-

periments at the molecular level, are

showing the effect of the higher ferromag-

netism of the Martian simulated soil on

the expression of DNA and RNA [7].

Conclusions

Life on Mars may require more than just

water alone. Studies of life on Mars may

require use of novel electro-chemical sen-

sors, and better understanding of the in-

teraction between the geo-chemical and

atmospheric elements of Mars and the

electro-chemistry of the kinetic of the

iron-oxidizing autotrophic microorgan-

isms. Perhaps the high iron content in

Martian soil is inducing high ferromagnet-ism, which is affecting the genomic ex-

pression, thus influencing the non-de-

tectable scarce life. The new findings of

life on Mars may change our understand-

ing of Life, thus having deep impact on

our society, scientific and technological

paradigms, way of thinking, living, philos-ophy, and on our economy. Maybe, life on

Mars is as different as the fiction-writers

envision

Literature

[1] Arny, T.: Explorations: an introduction to as-

tronomy, 3rd edition. McGraw-Hill Higher Ed-

ucation. NY. (2002)

[2] McKay, D.: Science 273: 924930 (1996)

[3] Kasting et al.: Report. NASA-Ames, CA (1986)

[4] D. R. Lovley: ASM News Vol. 68 (5): 231237

(2002)[5] DeDuve, (1995), Derek, (2002)

[6] T. El-Morsi et al., (2002), M. Kolb et al.,

(1992), Cuero et al., (2003)

[7] R. Cuero, D. McKay, Manuscript to be submit-

ted, (2003)

[8] Crundwell, F.: Biochemistry and Bioenerget-

ics 43: 115122 (1997)

For further literature please contact the author.

R. G. Cuero, Ph.D

Microbiologist

Distinguished Professor

Prairie View A&M UniversityTexas A&M University System

Texas, USA

olimpa@aol.com

Fig. 1: Growth of the autotrophic bacteria

Fig. 2: Martian simulated soil