Human exploration off planet is severely limited by the cost of launching materials into space and by re-supply. Thus materials brought from Earth must be light, stable and reliable at destination. ...Using traditional approaches, a lunar or Mars base would require either transporting a hefty store of metals or heavy manufacturing equipment and construction materials for in situ extraction; both would severely limit any other mission objectives. Long-term human space presence requires periodic replenishment, adding a massive cost overhead. Even robotic missions often sacrifice science goals for heavy radiation and thermal protection. Biology has the potential to solve these problems because life can replicate and repair itself, and perform a wide variety of chemical reactions including making food, fuel and materials. Synthetic biology enhances and expands life's evolved repertoire. Using organisms as feedstock, additive manufacturing through bioprinting will make possible the dream of producing bespoke tools, food, smart fabrics and even replacement organs on demand. This new approach and the resulting novel products will enable human exploration and settlement on Mars, while providing new manufacturing approaches for life on Earth.
While often obvious for macroscopic organisms, determining whether a microbe is dead or alive is fraught with complications. Fields such as microbial ecology, environmental health, and medical ...microbiology each determine how best to assess which members of the microbial community are alive, according to their respective scientific and/or regulatory needs. Many of these fields have gone from studying communities on a bulk level to the fine-scale resolution of microbial populations within consortia. For example, advances in nucleic acid sequencing technologies and downstream bioinformatic analyses have allowed for high-resolution insight into microbial community composition and metabolic potential, yet we know very little about whether such community DNA sequences represent viable microorganisms. In this review, we describe a number of techniques, from microscopy- to molecular-based, that have been used to test for viability (live/dead determination) and/or activity in various contexts, including newer techniques that are compatible with or complementary to downstream nucleic acid sequencing. We describe the compatibility of these viability assessments with high-throughput quantification techniques, including flow cytometry and quantitative PCR (qPCR). Although bacterial viability-linked community characterizations are now feasible in many environments and thus are the focus of this critical review, further methods development is needed for complex environmental samples and to more fully capture the diversity of microbes (e.g., eukaryotic microbes and viruses) and metabolic states (e.g., spores) of microbes in natural environments.
Tardigrades inhabiting terrestrial environments exhibit extraordinary resistance to ionizing radiation and UV radiation although little is known about the mechanisms underlying the resistance. We ...found that the terrestrial tardigrade Ramazzottius varieornatus is able to tolerate massive doses of UVC irradiation by both being protected from forming UVC-induced thymine dimers in DNA in a desiccated, anhydrobiotic state as well as repairing the dimers that do form in the hydrated animals. In R. varieornatus accumulation of thymine dimers in DNA induced by irradiation with 2.5 kJ/m(2) of UVC radiation disappeared 18 h after the exposure when the animals were exposed to fluorescent light but not in the dark. Much higher UV radiation tolerance was observed in desiccated anhydrobiotic R. varieornatus compared to hydrated specimens of this species. On the other hand, the freshwater tardigrade species Hypsibius dujardini that was used as control, showed much weaker tolerance to UVC radiation than R. varieornatus, and it did not contain a putative phrA gene sequence. The anhydrobiotes of R. varieornatus accumulated much less UVC-induced thymine dimers in DNA than hydrated one. It suggests that anhydrobiosis efficiently avoids DNA damage accumulation in R. varieornatus and confers better UV radiation tolerance on this species. Thus we propose that UV radiation tolerance in tardigrades is due to the both high capacities of DNA damage repair and DNA protection, a two-pronged survival strategy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A Makerspace for Life Support Systems in Space Snyder, Jessica E.; Walsh, David; Carr, Peter A. ...
Trends in biotechnology (Regular ed.),
11/2019, Letnik:
37, Številka:
11
Journal Article
Recenzirano
Human space exploration and settlement will require leaps forward in life support for environmental management and healthcare. Life support systems must efficiently use nonrenewable resources packed ...from Earth while increasingly relying on resources available locally in space. On-demand production of components and materials (e.g., 3D printing and synthetic biology) holds promise to satisfy the evolving set of supplies necessary to outfit human missions to space. We consider here life support systems for missions planned in the 2020s, and discuss how the maker and 'do-it-yourself' (DIY) biology communities can develop rapid, on-demand manufacturing techniques and platforms to address these needs. This Opinion invites the diverse maker community into building the next generation of flight hardware for near-term space exploration.
To establish a human settlement on the moon or Mars, NASA needs reliable life support systems that efficiently use nonrenewable resources packed from Earth while relying increasingly on resources available locally in space – solar energy and biological resources.Equipment for the life support system will need repair during multiyear missions. Earth will resupply when possible, but the crew will also make components in their own habitat during the mission.Both mechanical and biological ultra-low size, weight, and power (UL-SWaP) devices satisfy such technology gaps to continually maintain a habitable atmosphere.As pioneers of rapid prototyping on limited resources, the maker community could propel space travel forward by developing technologies consistent with the needs of human missions: efficient (UL-SWaP), automated, networked, and modular.
Editing nature: Local roots of global governance Kofler, Natalie; Collins, James P; Kuzma, Jennifer ...
Science (American Association for the Advancement of Science),
11/2018, Letnik:
362, Številka:
6414
Journal Article
Recenzirano
Environmental gene editing demands collective oversight
The end of malaria. Restored island habitats. Resiliency for species threatened by climate change. Many envisioned environmental applications ...of newly developed gene-editing techniques such as CRISPR might provide profound benefits for ecosystems and society. But depending on the type and scale of the edit, gene-edited organisms intentionally released into the environment could also deliver off-target mutations, evolutionary resistance, ecological disturbance, and extinctions. Hence, there are ongoing conversations about the responsible application of CRISPR, especially relative to the limitations of current global governance structures to safeguard its use (
1
,
2
); see table S1. Largely missing from these conversations is attention to local communities in decision-making. Most policy discussions are instead occurring at the national or international level (
3
,
4
), even though local communities will be the first to feel the context-dependent impacts of any release. To be fully representative, therefore, local inputs and perspectives must also be considered. As laboratories around the world develop and perfect gene-editing techniques with unprecedented capacity to alter wild species and, by extension, the ecological and cultural systems of which they are a part, we outline our vision for locally based, globally informed governance.
Summary
High‐strength polymers, such as aramid fibres, are important materials in space technology. To obtain these materials in remote locations, such as Mars, biological production is of interest. ...The aromatic polymer precursor para‐aminobenzoic acid (pABA) can be derived from the shikimate pathway through metabolic engineering of Bacillus subtilis, an organism suited for space synthetic biology. Our engineering strategy included repair of the defective indole‐3‐glycerol phosphate synthase (trpC), knockout of one chorismate mutase isozyme (aroH) and overexpression of the aminodeoxychorismate synthase (pabAB) and aminodeoxychorismate lyase (pabC) from the bacteria Corynebacterium callunae and Xenorhabdus bovienii respectively. Further, a fusion‐protein enzyme (pabABC) was created for channelling of the carbon flux. Using adaptive evolution, mutants of the production strain, able to metabolize xylose, were created, to explore and compare pABA production capacity from different carbon sources. Rather than the efficiency of the substrate or performance of the biochemical pathway, the product toxicity, which was strongly dependent on the pH, appeared to be the overall limiting factor. The highest titre achieved in shake flasks was 3.22 g l−1 with a carbon yield of 12.4% C‐mol/C‐mol from an amino sugar. This promises suitability of the system for in situ resource utilization (ISRU) in space biotechnology, where feedstocks that can be derived from cyanobacterial cell lysate play a role.
Bacillus subtilis was genetically engineered for production of para‐aminobenzoic acid. End‐product toxicity appeared to be limiting due to a pH‐drop during cultivation. Utilisation of acetyl‐glucosamine as carbonsource alleviated the toxic effect by inverting the pH‐shift.
Amyloid‐based prions have simple structures, a wide phylogenetic distribution, and a plethora of functions in contemporary organisms, suggesting they may be an ancient phenomenon. However, this ...hypothesis has yet to be addressed with a systematic, computational, and experimental approach. Here we present a framework to help guide future experimental verification of candidate prions with conserved functions to understand their role in the early stages of evolution and potentially in the origins of life. We identified candidate prions in all high‐quality proteomes available in UniProt computationally, assessed their phylogenomic distributions, and analyzed candidate‐prion functional annotations. Of the 27 980 560 proteins scanned, 228 561 were identified as candidate prions (~0.82%). Among these candidates, there were 84 Gene Ontology (GO) terms conserved across the three domains of life. We found that candidate prions with a possible role in adaptation were particularly well‐represented within this group. We discuss unifying features of candidate prions to elucidate the primeval roles of prions and their associated functions. Candidate prions annotated as transcription factors, DNA binding, and kinases are particularly well suited to generating diverse responses to changes in their environment and could allow for adaptation and population expansion into more diverse environments. We hypothesized that a relationship between these functions and candidate prions could be evolutionarily ancient, even if individual prion domains themselves are not evolutionarily conserved. Candidate prions annotated with these universally occurring functions potentially represent the oldest extant prions on Earth and are therefore excellent experimental targets.
The evolution of photosynthesisagain? Rothschild, Lynn J
Philosophical transactions of the Royal Society of London. Series B. Biological sciences,
08/2008, Letnik:
363, Številka:
1504
Journal Article
Recenzirano
Replaying the tape is an intriguing would it happen again? exercise. With respect to broad evolutionary innovations, such as photosynthesis, the answers are central to our search for life elsewhere. ...Photosynthesis permits a large planetary biomass on Earth. Specifically, oxygenic photosynthesis has allowed an oxygenated atmosphere and the evolution of large metabolically demanding creatures, including ourselves. There are at least six prerequisites for the evolution of biological carbon fixation: a carbon-based life form; the presence of inorganic carbon; the availability of reductants; the presence of light; a light-harvesting mechanism to convert the light energy into chemical energy; and carboxylating enzymes. All were present on the early Earth. To provide the evolutionary pressure, organic carbon must be a scarce resource in contrast to inorganic carbon. The probability of evolving a carboxylase is approached by creating an inventory of carbon-fixation enzymes and comparing them, leading to the conclusion that carbon fixation in general is basic to life and has arisen multiple times. Certainly, the evolutionary pressure to evolve new pathways for carbon fixation would have been present early in evolution. From knowledge about planetary systems and extraterrestrial chemistry, if organic carbon-based life occurs elsewhere, photosynthesisalthough perhaps not oxygenic photosynthesiswould also have evolved.
Life in extreme environments Rothschild, Lynn J; Mancinelli, Rocco L
Nature,
02/2001, Letnik:
409, Številka:
6823
Journal Article
Recenzirano
Odprti dostop
Each recent report of liquid water existing elsewhere in the Solar System has reverberated through the international press and excited the imagination of humankind. Why? Because in the past few ...decades we have come to realize that where there is liquid water on Earth, virtually no matter what the physical conditions, there is life. What we previously thought of as insurmountable physical and chemical barriers to life, we now see as yet another niche harbouring 'extremophiles'. This realization, coupled with new data on the survival of microbes in the space environment and modelling of the potential for transfer of life between celestial bodies, suggests that life could be more common than previously thought. Here we examine critically what it means to be an extremophile, and the implications of this for evolution, biotechnology and especially the search for life in the Universe.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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