Content uploaded by David Thomas
Author content
All content in this area was uploaded by David Thomas
Content may be subject to copyright.
Genetic modification and selection of microorganisms for growth on Mars
Abstract
Genetic engineering has often been suggested as a mechanism for improving the survival prospects of terrestrial microoganisms when seeded on Mars. The survival characteristics that these pioneer microorganisms could be endowed with and a variety of mechanisms by which this can be achieved are discussed, together with an overview of some of the potential hurdles that must be overcome. Also, a number of biologically useful properties for these microorganisms are presented that could facilitate the initial human colonisation and ultimately the planetary engineering of Mars.
... Humans have been using genetically modified microorganism for centuries for food, medicine, bioremediation, and industries. With the progress in genetic engineering technologies, the metabolic potentials of various microbes are being explored and used to improve and develop microbes with desired characters (Hiscox, 1995). Majorly the understanding of microbes and their different capabilities such as production of industrially important products, remediation, etc in regard to their complex biology has been through genetic manipulation. ...
... Many of these hard environmental conditions added to the aforementioned along with the geophysical characteristics of the sampling site in combination (Fig. 5) resemble those present in the early Earth's atmosphere that gave rise to the evolution of the ancient microorganisms (Cabrol et al. 2007;Albarracín et al. 2015;Cockell et al. 2000;Yen et al. 2006;Karunatillake et al. 2007;Hecht et al. 2009;Sforna et al. 2014;Forni et al. 2015;Wadsworth and Cockell 2017). Thus, Act20 is an exciting model organism to study the mechanisms by which the extremophiles could have successfully faced the adverse conditions of the Earth's primordial history, with also clear implications in astrobiological projects (Hiscox and Thomas 1995;Slotnick 2000;Merino et al. 2019). ...
Central-Andean Ecosystems (between 2000 and 6000 m above sea level (masl) are typical arid-to-semiarid environments suffering from the highest total solar and ultraviolet-B radiation on the planet but displaying numerous salt flats and shallow lakes. Andean microbial ecosystems isolated from these environments are of exceptional biodiversity enduring multiple severe conditions. Furthermore, the polyextremophilic nature of the microbes in such ecosystems indicates the potential for biotechnological applications. Within this context, the study undertaken used genome mining, physiological and microscopical characterization to reveal the multiresistant profile of Nesterenkonia sp. Act20, an actinobacterium isolated from the soil surrounding Lake Socompa, Salta, Argentina (3570 masl). Ultravioet-B, desiccation, and copper assays revealed the strain’s exceptional resistance to all these conditions. Act20’s genome presented coding sequences involving resistance to antibiotics, low temperatures, ultraviolet radiation, arsenic, nutrient-limiting conditions, osmotic stress, low atmospheric-oxygen pressure, heavy-metal stress, and toxic fluoride and chlorite. Act20 can also synthesize proteins and natural products such as an insecticide, bacterial cellulose, ectoine, bacterial hemoglobin, and even antibiotics like colicin V and aurachin C. We also found numerous enzymes for animal- and vegetal-biomass degradation and applications in other industrial processes. The resilience of Act20 and its biotechnologic potential were thoroughly demonstrated in this work.
... In addition, third, because the extreme conditions strongly limit the possibilities of invader species to succeed, appropriate strategies will need to consider the use of extremophiles [108,109] or the engineering of new microbial life forms able to cope with those conditions. Synthetic biology of soil microbial life forms is likely to be the most promising way of dealing with the gap to restart a novel biosphere [18,133]. ...
What is the potential for synthetic biology as a way of engineering, on a large scale, complex ecosystems? Can it be used to change endangered ecological communities and rescue them to prevent their collapse? What are the best strategies for such ecological engineering paths to succeed? Is it possible to create stable, diverse synthetic ecosystems capable of persisting in closed environments? Can synthetic communities be created to thrive on planets different from ours? These and other questions pervade major future developments within synthetic biology. The goal of engineering ecosystems is plagued with all kinds of technological, scientific and ethic problems. In this paper, we consider the requirements for terraformation, i.e., for changing a given environment to make it hospitable to some given class of life forms. Although the standard use of this term involved strategies for planetary terraformation, it has been recently suggested that this approach could be applied to a very different context: ecological communities within our own planet. As discussed here, this includes multiple scales, from the gut microbiome to the entire biosphere.
... And third, that because the extreme conditions strongly limit the possibilities of invader species to succeed, appropriate strategies will need to consider the use of extremophiles [114,126] or the engineering of new microbial life forms able to cope with those conditions. Synthetic biology of soil microbial life forms is likely to be the most promising way of dealing with the gap to restart a novel biosphere [49,121]. ...
What is the potential for synthetic biology as a way of engineering, on a large scale, complex ecosystems? Can it be used to change endangered ecological communities and rescue them to prevent their collapse? What are the best strategies for such ecological engineering paths to succeed? Is it possible to create stable, diverse synthetic ecosystems capable of persisting in closed environments? Can synthetic communities be created to thrive on planets different from ours? These and other questions pervade major future developments within synthetic biology. The goal of engineering ecosystems is plagued with all kinds of technological, scientific and ethic problems. In this paper we consider the requirements for Terraformation, i. e. for changing a given environment to make it hospitable to some given class of life forms. Although the standard use of this term involved strategies for planetary terraformation, it has been recently suggested that this approach could be applied to a very different context: ecological communities within our own planet. As discussed here, this includes multiple scales, from the gut microbiome to the entire biosphere.
... One of the more ambitious proposals is to engage in terraforming, which is the creation of livable environments on otherwise inhospitable extraterrestrial planets and other bodies of mass (Fogg, 1995(Fogg, ,1998Graham, 2004;McKay and Marinova, 2001). Terraforming proposals involve approaches such as using photosynthetic organisms to create an oxygen-rich atmosphere (Friedmann and Ocampo-Friedmann, 1995;Hiscox and Thomas, 1995), heating polar ice caps, such as the water-and-CO2 ice cap on Mars, to create a greenhouse gas atmosphere to warm the planet (Sagan, 1973;Mole, 1995; but see Fogg, 1995Fogg, , 1998, and putting megascale mirrors in a planet's orbit to reflect more radiation towards it and warm it (Birch, 1992). ...
Atomically precise manufacturing (APM) is the assembly of materials with atomic precision. APM does not currently exist, and may not be feasible, but if it is feasible, then the societal impacts could be dramatic. This paper assesses the net societal impacts of APM across the full range of important APM sectors: general material wealth, environmental issues, military affairs, surveillance, artificial intelligence, and space travel. Positive effects were found for material wealth, the environment, military affairs (specifically nuclear disarmament), and space travel. Negative effects were found for military affairs (specifically rogue actor violence and AI. The net effect for surveillance was ambiguous. The effects for the environment, military affairs, and AI appear to be the largest, with the environment perhaps being the largest of these, suggesting that APM would be net beneficial to society. However, these factors are not well quantified and no definitive conclusion can be made. One conclusion that can be reached is that if APM R&D is pursued, it should go hand-in-hand with effective governance strategies to increase the benefits and reduce the harms.
... Some of the most popular extremophiles discussed (Hiscox & Thomas, 1995;Budzik, 2000;Slotnick, 2000) in the context of terraforming are: ...
As humankind heads into space, one of our primary goals is to find new worlds to settle. Mars stands out as far and away the most practical choice to begin this next phase of human civilization. Apart from its relative closeness, one of the main reasons for this is Mars's potential for terraforming. The red planet's characteristics, while representing challenges, offer an opportunity for the manifestation of a vision which has permeated human thought since the dawn of science fiction – another planet that humans can walk on without the need for a spacesuit; a planet with air, water, soil, plants and animals. Numerous thinkers have contributed to the development of terraforming strategies. This paper expands on previous work, incorporating our current understanding of Mars as well as emerging technologies. The result is a strategy that incorporates past ideas with several new ones. Terraforming is organised into 3 primary tasks: increasing the temperature, building the atmosphere, and implanting the biosphere. These are implemented in stages, favouring solutions that are controllable yet still fast. The use of robotics and genetic engineering are emphasized, based on the assumption that these technologies will be much more advanced, probably even commonplace, during the 21 st – 22 nd century.
Terraforming is the process of modifying a planet, moon, or other body to a more habitable atmosphere, temperature, or ecology. The idea of terraforming or colonizing other planets has recently become a topic of intense scientific interest and public debate. Geoengineering and terraforming, at their core, have the same goal: to enhance or revive the ability of a specific environment to support human life, society, and industry. New Worlds: Colonizing Planets, Moons and Beyond examines extra-terrestrial colonization plans with a critical eye. The ten chapters of the book provide a detailed review of the demographic and economic reasons behind this space imperative, technical and ecological solutions to improve the settlement of our own planet, enhancements of our current space industry. The book also covers interesting topics such as the terraformation of Mars, the moon, and other planets like Venus, colonizing the outer solar system (and beyond), and the ethical considerations in favor of space expansion. This simple, yet informative treatise is an essential read for anyone interested in the subject of space colonization
Terraforming is the process of modifying a planet, moon, or other body to a more habitable atmosphere, temperature, or ecology. The idea of terraforming or colonizing other planets has recently become a topic of intense scientific interest and public debate. Geoengineering and terraforming, at their core, have the same goal: to enhance or revive the ability of a specific environment to support human life, society, and industry. New Worlds: Colonizing Planets, Moons and Beyond examines extra-terrestrial colonization plans with a critical eye. The ten chapters of the book provide a detailed review of the demographic and economic reasons behind this space imperative, technical and ecological solutions to improve the settlement of our own planet, enhancements of our current space industry. The book also covers interesting topics such as the terraformation of Mars, the moon, and other planets like Venus, colonizing the outer solar system (and beyond), and the ethical considerations in favor of space expansion. This simple, yet informative treatise is an essential read for anyone interested in the subject of space colonization
The concept of modifying the environment of another planet, so that it can support terrestrial life, is known as terraforming. As a speculative thought experiment in planetary engineering, it has been slowly gaining in respectability and, over the past 40 years, has amassed a considerable body of published work. In this paper, the progress of research into the terraforming of the planet Mars is briefly reviewed. While such an undertaking does not appear technologically impossible, whether it will actually happen is an unanswerable question. However, the control space for thought experimentation that terraforming provides is of use in planetological research, environmental ethics, and education. The subject is therefore relevant to the present day, as well as to a possible future.
Samples from an Oligocene silver-bearing manganese ore mining site in Saguochi country, Colorado were screened for bacteria which solubilize manganese in the refractory ore thus making the silver more amenable to standard extraction techniques. Over 300 bacterial isolates were tested. Manganese reduction was detected by growing the organisms in a mineral salts medium supplemented with the insoluble MnO2 (pyrolusite). Reduction of the black MnO2 resulted in the formation of colorless solubilized Mn²⁺. One of the most efficient manganese reducers was a Bacillus polymyxa strain D1. This bacterium was isolated from the ore heap and from a zone 5 cm below the sediment surface of the inlet which drained ore heap leachate into a holding pond. Isolate D1 has a unique mode of manganese reduction as shown by the following combination of characteristics: (1) anaerobiosis is absolutely necessary; (2) direct surface contact with the mineral particle is required; (3) facultative fermentation occurs concomitantly with manganese reduction; and (4) Mn⁴⁺ does not substitute for O2 at the end of the respiratory electron transport chain.
This paper addresses the problems of terraforming Mars quickly. It is shown that a solar mirror could be used to vaporize portions of the Martian regolith, liberating trapped volatiles including oxygen, nitrogen, carbon dioxide, and water vapor. The creation of a breathable atmosphere could then be completed by photosynthesis. Illumination from the same soletta would then provide a warm climate around the new canals and sunlight on the high deserts, maintaining the 24.5 hour cycle of day and night. It is claimed that terraforming could be completed in as little as fifty years.
The subspeciesNostoc commune var.flagelliforme andN. commune var.commune are found in China (Ningxia Province, Inner Mongolia) as two morphologically different ecotypes of the desiccation-independent
cyanobacteriumN. commune. The first ecotype, but not the second, colonizes arid areas. Various biochemical parameters and water dependence of photosynthesis
and nitrogen fixation were compared for both ecotypes. Different patterns of water stress proteins were found in the two ecotypes.
Repeated desiccation resulted in an enhanced desiccation independence for photosynthesis and, in the case of the ecotypecommune, for nitrogen fixation. The different response of nitrogenase of both ecotypes towards repeated cycles of rewetting and desiccation
under conditions simulating the natural environment is discussed in terms of the energy balance of the colonies that are adapted
to different environmental conditions.
Previous outline proposals for terraforming Mars nearly all require, as
a first step, the creation of a dense atmosphere of carbon dioxide, with
a surface pressure of about 1 bar and with sufficient greenhouse effect
to raise surface temperatures above 273 K. However, since it is now
thought that the bulk of Mars' CO2 inventory lies either within
carbonate rocks or has been lost from the planet in an early episode of
impact erosion, this first step may be more difficult to achieve than
commonly appreciated. If carbonate-bearing minerals are abundant within
the Martian regolith, it would be necessary to devolatilize them to
return their store of CO2 into the atmosphere. The most practical way to
do this would be through the use of buried thermonuclear explosives. It
is shown that at least ten million such explosives, in the multi-megaton
range, buried at depths of hundreds of meters would be required. All
materials required for their fabrication could be obtained from Martian
resources. The most serious objection to such a scheme is that Mars is
likely to be settled before terraforming becomes practical, thus ruling
out highly energetic or intrusive engineering techniques.
The objective of terraforming is to alter the environment of a planet in
order to improve the chances of survival of an indigenous biology or to
allow habitation by most, if not all, terrestrial life forms. It is
found that, within our Solar System, Mars is the only planet which could
possibly be terraformed using foreseeable techniques. Terraforming Mars
would involve two stages: first, warming the surface and increasing the
surface pressure, and second, chemically altering the composition of the
atmosphere. Estimates for the timescales of the first and second stage
are 100 and 100,000 years, respectively. Constant technological input
woul; only be required during the first stage.
A two-stage terraforming scenario is outlined for Mars. The approach
adopted differs from past methodology in two ways. It adopts a more
conservative and plausible Martian volatile inventory. Possible
planetary engineering solutions, including possible synergic use of
terraforming techniques, are examined in detail. In the first stage, the
Martian environment is modified to a state where it can support
microbial and hardy plant life in approximately 200 years. While this
step is conceptually similar to past scenarios, it differs greatly in
detail. The second stage deals with the creation of conditions tolerable
for human beings over a period of approximately 21,000 years. It is
concluded that terraforming Mars is possible but not by the passive, or
near-spontaneous, methods favored by some workers. A powerful industrial
effort is required both on the planet's surface and in space as will be
continuing technological intervention to stabilize the postterraformed
regime.
Halophilic microorganisms were isolated from Triassic and Permian salt deposits. Two were rods and grew as red colonies; another was a coccus and produced pink colonies. The rods lysed in solutions that lacked added sodium chloride. Growth of all isolates was inhibited by aphidicolin and their bulk proteins were acidic as judged from isoelectric focusing. Therefore, these organisms were tentatively identified as extreme halophiles. Whole cell proteins patterns of the isolates following gel electrophoresis were distinct and differed from those of representative type strains of halophilic bacteria. The membrane ATPases from the rods were similar to the enzyme fromHalobacterium saccharovorum with respect to subunit composition, enzymatic properties and immunological cross-reaction, but differed slightly in amino acid composition. If the age of the microbial isolated is similar to that of the salt deposits, they can be considered repositories of molecular information of great evolutionary interest.
Rhodopseudomonas sphaeroides f. denitrificans grown photosynthetically with NO
3-under anaerobic conditions accumulated NO
2-in the culture medium. In washed cells succinate, lactate, fumarate, citrate and malate, were effective electron donors for the reduction of NO
3-, NO
2-and N2O to N2 gas. Nitrate reductase was inhibited by amytal and potassium thocyanate. Nitrite reductase activity was severely restricted by potassium cyanide, sodium diethyldithiocarbamate, Amytal and 2-n-heptyl-4-hydroxyquinoline-N-oxide whereas N2O reductase was inhibited by NaN3, C2H2 and KCNS. Cells incubated with either K15NO3 or K15NO2 produced 15N2O and 15N2. A stoichiometry of 2:1 was recorded for the reduction of either NO
3-or NO
2-to N2O and N2 and for N2O to N2 it was 1:1.
The concept of modifying the environment of another planet, so that it can support terrestrial life, is known as terraforming. As a speculative scientific subject, it has been slowly gaining in respectability and, over the past 30 years, has amassed a considerable body of published work. In this paper, the present day capabilities of civilisation to bring about global environmental change are breifly discussed, followed by a review of the progress of research into the terraforming of the planet Mars. Whilst such an undertaking does not appear technologically impossible, whether it will actually happen is an unanswerable question. However, the control space for thought experimentation that terraforming provides is of use for both planetological research and education. The subject is therefore relevant to the present day, as well as to a possible future.
An energy balance model has been developed to investigate how the Martian atmospheric environment could influence a community of photosynthetic microorganisms with properties similar to those of a cyanophyte (blue-green algal mat) and a lichen. Surface moisture and soil nutrients are assumed to be available. The model was developed to approximate equatorial equinox conditions and includes parameters for solar and thermal radiation, convective and conductive energy transport, and evaporative cooling. Calculations include the diurnal variation of organism temperature and transpiration and photosynthetic rates. The influences of different wind speeds and organism size and resistivity are also studied. The temperature of organisms in mats less than a few millimeters thick will not differ from the ground temperature by more than 10°K. Water loss is actually retarded at higher wind speeds, since the organism temperature is lowered, thus reducing the saturation vapor pressure. Typical photosynthetic rates lead to the production of 10−6 to 10−7 mole O2 cm−2 day−1.