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At least 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Developing Model Benchtop Systems for Microbial Experimental Evolution

Understanding how microbes impact an ecosystem has improved through advances of molecular and genetic tools, but creating complex systems that emulate natural biology goes beyond current technology. In fact, many chemical, biological, and metabolic pathways of even model organisms are still poorly characterized. Even then, standard laboratory techniques for testing microbial impact on environmental change can have many drawbacks; they are time-consuming, labor intensive, and are at risk of contamination. By having an automated process, many of these problems can be reduced or even eliminated. We are developing a benchtop system that can run for long periods of time without the need for human intervention, involve multiple environmental stressors at once, perform real-time adjustments of stressor exposure based on current state of the population, and minimize contamination risks. Our prototype device allows operators to generate an analogue of real world micro-scale ecosystems that can be used to model the effects of disruptive environmental change on microbial ecosystems. It comprises of electronics, mechatronics, and fluidics based systems to control, measure, and evaluate the before and after state of microbial cultures from exposure to environmental stressors. Currently, it uses four parallel growth chambers to perform tests on liquid cultures. To measure the population state, optical sensors (LED/photodiode) are used. Its primary selection pressure is UV-C radiation, a well-studied stressor known for its cell- and DNA-damaging effects and as a mutagen. Future work will involve improving the current growth chambers, as well as implementing additional sensors and environmental stressors into the system. Full integration of multiple culture testing will allow inter-culture comparisons. Besides the temperature and OD sensors, other types of sensors can be integrated such as conductivity, biomass, pH, and dissolved gasses such as CO and O. Additional environmental stressor systems like temperature (extreme heat or cold), metal toxicity, and other forms of radiation will increase the scale and testing range.

Developing↗
NASA NTRS2017

One Step Closer to Mars with Aquaponics: Cultivating Citizen Science in K12 Schools

The Microbial Ecology and Biogeochemistry Research Laboratory at NASA Ames Research Center focuses primarily on the nutrient cycling and diversity of complex microbial communities. NASA is interested in the composition and functioning of microbial mat communities as these processes fundamentally shape the form and function of these analogs for the earliest forms of life on Earth (3.6 billion years ago), and likely will on other planets as well. Aquaponics systems are supported by microbial communities who perform many complex ecosystem services, including cycling nitrogen. Microbes are integral to the stability and productivity of aquaponics systems, which are analogous to microbial communities in food production systems that are essential for building efficient life support systems for long-distance space travel. Students at Meadow Park Middle School created 10 parallel aquaponics systems and took temporal microbial samples to characterize whether any macro-ecology variables impacted or changed the microbial diversity of these systems. Students additionally created a website so that other classrooms can pursue similar projects in their own schools (https://go.nasa.gov/2uJhxmF). Our lab at NASA Ames has sequenced water samples from each of the 10 tanks at 3 timepoints using a MinION sequencer. MPMS students will be involved in the analysis of the bioinformatics data generated through this collaboration. Our ongoing collaboration aims to collect and analyze data in the classroom setting that has utility for research scientists, while involving students as collaborators in the research process.

Kolattukudy, Maria↗
NASA NTRS2018

A Microbial Analysis of Space-Grown Produce

Before space crops become a permanent staple of the astronaut diet, we must first understand how plants and pathogenic microbes interact in microgravity. Crops such as red romaine lettuce and Chinese cabbage were grown on the International Space Station and sent back to Kennedy Space Center for microbial analysis. Aerobic plate counts and metagenomic sequencing were used to characterize bacterial and fungal communities for plants and their respective ''pillows''. These data will be used to create new guidelines for the microbial safety of space-grown produce, and will help us better protect astronauts from food-borne pathogens like E.coli, Staphylococcus, and Salmonella.

Barash, Eric L.↗
NASA NTRS2018

A Prototype Tool for Assessing Forward Contamination from Space Suits

Crewed exploration missions dramatically increase the capability for large-scale sample collection and return activities, but they also increase the possibility and likelihood of forward contamination. Systematic research on forward contamination from uncrewed spacecraft has steadily progressed since the Viking missions, but parallel research on contamination from space suits has not. Current space suits have leakage rates as high as 100 cc gas/min., but it is unclear how many or what types of microbes are exiting the suits along with this gas. The Human Forward Contamination Assessment team at NASA's Johnson Space Center (JSC) has developed a prototype swab tool that is capable of maintaining sterility during pressure changes associated with entering and exiting vacuum. The primary objective of recent Extravehicular Activity (EVA) Swab Kit testing is to characterize the type of microorganisms typically found on spacesuit external surfaces under suit differential pressure conditions. Most human-associated microorganisms can fit through a 0.5 to 1.0 μm gap. Understanding potential leak paths will inform future hardware design decisions. Knowing which types of microorganisms may leak from EVA suits provides a basis for subsequent studies to characterize the viability of those organisms under destination conditions, as well as how far they might spread through natural or human-influenced processes. The results of EVA suit molecular microbial community analyses will inform NASA exploration mission operations and hardware design, and help close Strategic Knowledge Gap B5, Forward Contamination to Mars.

Rucker, M.↗
NASA NTRS2018

Microbial Ecology of NASA Curation Clean Rooms

Clean room standards like ISO 14644 used for facilities that construct spacecraft and store returned samples do not explicitly account for microbial contamination. While there are associated ISO standards for monitoring and controlling bio-contamination in clean rooms it is not always standard practice to do so. The NASA Astromaterials Acquisition and Curation Office maintains seven separate clean labs for storing extraterrestrial samples from the Moon, meteorites, cosmic dust, asteroids, comets, solar wind particles, and microparticle impact samples. These labs are routinely monitored for particulate and trace metal contamination. However, the sample collections are either non-sterile at the time of collection (e.g., meteorites) or are no longer being used to address scientific questions that could be affected by non-sterile conditions (e.g., Lunar samples). Outside of isolated studies there has not been a systematic, longitudinal characterization of the microbial ecology of NASA curation clean rooms. In accordance with the advanced curation initiative, and to prepare for future sample return missions, we have initiated a routine microbiological monitoring program in the Antarctic Meteorite Lab. This monitoring program will be used to determine what microbes are capable of surviving in these oligotrophic environments and whether or not they are capable of altering the sample collections in any significant manner. Repeat sampling will allow us to understand how routine use of these labs affects the microbial ecology over time.

Regberg, A. B.↗
NASA NTRS2018

Bioreduction of Solid Rocket Motors for Planetary Protection

Solid rocket propulsion systems have been used for in-space applications including planetary exploration missions for many years. Current NASA science lander projects require solid rocket propulsion systems to touchdown on the surface of potentially life-supporting planets and moons. A critical requirement of these missions is the prevention of accidental transportation of Earth's microbes to these environments. This mission requirement places an increased importance on the ability to reduce the biological burden that may be on board the solid propulsion systems and potentially deposited in a habitable environment. Some traditional interplanetary spacecraft decontamination operations could reduce the reliability of the solid propulsion system, indicating a need for new decontamination procedures. New techniques for biological burden reduction are being studied and may become the method of choice to ensure adequate reduction has been achieved. These techniques include biocidal elimination through chemical agents already present within the motor and cellular disruption due to assembly and operational environments induced in the motor. Recent investigations into the effectiveness of these techniques have generated promising experimental results. These techniques and current experimental results will be presented.

Boyle, Sadie M.↗
NASA NTRS2018

GeneLab: "Omics" Data Systems for Spaceflight and Simulated Spaceflight Environment

NASA's GeneLab Data System is a repository that hosts multi-omics datasets generated by biological experiments flown onboard the International Space Station. Strategies regarding how GeneLab envisions the involvement of the scientific community and the public at large will be discussed, and current and future capabilities of the system will be described. Information describing how scientists can participate in analyzing the current datasets on plants, microbes, invertebrates or mammals will be provided, and initial findings from the current datasets will be discussed during this presentation. Anyone interested in genomics, transcriptomics, epigenomics and proteomics, and systems biology, or who is curious to understand how space modifies living organisms should attend.

Omics↗
NASA NTRS2018

In-space Biomanufacturing Using CO2 with Methylobacterium Extorquens

Long duration missions to deep space will require new approaches for supplying astronauts. In-space microbial manufacturing could generate many important compounds (such as nutrients, pharmaceuticals and fuels) but there are significant barriers to deploying reliable bioproduction platforms to space. These include ensuring adequate production and proper purification of the desired product, especially in the unique radiation and microgravity environment. Here we are focused on developing methods and technologies to feed microbial factories using the resources available in space. CO2, found in abundance in spacecraft cabins and the Mars atmosphere, can be sequestered and converted into bioproducts. While autotrophic organisms can use CO2 directly, they are generally slow growing and have less-developed biotechnology toolkits. Therefore we are developing an alternative paradigm in which CO2 is first reduced to more energetic carbon compounds that can support more rapid growth of workhorse biotechnology platforms (E. coli, S. cerevisiae, P. pastoris).Various technologies exist or are being developed to convert CO2. For example, the Sabatier system currently installed on the ISS, reacts CO2 and H2 to generate CH4 and H2O. This methane could be consumed by engineered methanotrophic bacteria. Alternatively, electrochemical systems can convert CO2 into formate (CHO2) which could be consumed by formatotrophic bacteria. In either case, synthetic biology techniques allow these microbes to serve as reprogrammable biofactories capable of producing a vast number or products.

Synthetic biology; Formate metabolism↗
NASA NTRS2018

Investigating Microbiome Differences Between Red Romaine Lettuce Grown from Sanitized and Unsanitized Seeds

The International Space Station (ISS) as an integral component for the discovery and development of advanced robotics, materials, communications, medicine, agriculture, and environmental science due to it currently being the world's only microgravity laboratory of its kind. Because the ISS is a contained system with confined quarters, much research has been undertaken to assess and diminish the number of microbiological risks associated with astronauts inhabiting the station for extended periods of time. Notable microbiological risk factors include drinking water, air, and food. As an avenue for both mental/emotional respite and a source of fresh produce for astronauts, a vegetable production system has been employed on the ISS. In order to understand the microbial risks involved with a "pick and eat" vegetable system on the International Space Station (ISS), this study aims to compare microbial differences between sanitized and unsanitized seeds by tracking and identifying seedborne microbes throughout the development of red romaine lettuce (Lactuca sativa)-a plant species that has already been grown on the ISS.

Polanco, Jonilee A.↗
NASA NTRS2018

Carbon-Nitrogen Coupling Under Three Schemes of Model Representation: A Traceability Analysis

The interaction between terrestrial carbon (C) and nitrogen (N) cycles has been incorporated into more and more land surface models. However, the scheme of C-N coupling differs greatly among models, and how these diverse representations of C-N interactions will affect C-cycle modeling remains unclear. In this study, we explored how the simulated ecosystem C storage capacity in the terrestrial ecosystem (TECO) model varied with three different commonly used schemes of C-N coupling. The three schemes (SM1, SM2, and SM3) have been used in three different coupled C-N models (i.e., TECO-CN, CLM 4.5, and O-CN, respectively). They differ mainly in the stoichiometry of C and N in vegetation and soils, plant N uptake strategies, down regulation of photosynthesis, and the pathways of N import. We incorporated the three C-N coupling schemes into the C-only version of the TECO model and evaluated their impacts on the C cycle with a traceability framework. Our results showed that all three of the C-N schemes caused significant reductions in steady-state C storage capacity compared with the C-only version with magnitudes of −23%, −30%, and −54% for SM1, SM2, and SM3, respectively. This reduced C storage capacity was mainly derived from the combined effects of decreases in net primary productivity (NPP; −29%, −15%, and −45%) and changes in mean C residence time (MRT; 9%, −17%, and −17%) for SM1, SM2, and SM3, respectively. The differences in NPP are mainly attributed to the different assumptions on plant N uptake, plant tissue C : N ratio, down regulation of photosynthesis, and biological N fixation. In comparison, the alternative representations of the plant vs. microbe competition strategy and the plant N uptake, combined with the flexible C : N ratio in vegetation and soils, led to a notable spread in MRT. These results highlight the fact that the diverse assumptions on N processes represented by different C-N coupled models could cause additional uncertainty for land surface models. Understanding their difference can help us improve the capability of models to predict future biogeochemical cycles of terrestrial ecosystems.

Du, Zhenggang↗
NASA NTRS2018

Hopanoids Producing Bacteria and Related Biofertilizers, Compositions, Methods and Systems

Hopanoids, hopanoids-producing nitrogen-fixing bacteria, and related formulations, systems and methods are described herein. In particular, hopanoids alone or in combination with hopanoid-producing nitrogen-fixing bacteria can be used as biofertilizer to stimulate plant growth and yield with enhanced tolerance to diverse stresses found in plant-microbe symbiotic microenvironments.

Newman, Dianne K.↗
NASA NTRS2019

Analysis of Seed Sanitization, Rapid Freezer Proficiency, and Veg-03 Water Verification

In order to ensure the well-being of astronauts and experiments on the ISS (International Space Station), seeds need to be free of microbes, the rapid freezer needs to be freezing biological samples evenly and proficiently, and the astronauts need to have accurate watering procedures for Veg-03 (the latest Phytotron for the Veggie (Vegetable Production System) project). Seed flight candidates were sanitized with varying levels of HCL in order to determine the right amount to use for future flight experiments, too much HCL and the seeds will not germinate and too little and they will be contaminated with microorganisms. The rapid freezer was assessed using temperature probes to determine if there is a homogeneous change in temperature in order to ensure the safe freezing of biological organisms. The plant watering procedures given to the astronauts were assessed in order to make sure that Veg-03 experiments are receiving the correct amount of water.

Hollingsworth, Savannah↗
NASA NTRS2019

GeneLab: A Systems Biology Platform for Omics Analysis

NASA's GeneLab includes an open-access repository of some 200+ omics datasets generated by biological experiments relevant to spaceflight (including simulated cosmic radiation and microgravity). In order to maximize the intelligibility of these data, particularly for users with limited bioinformatics knowledge, GeneLab is now transforming the data in the repository into actual biological and physiological knowledge of the genetic and proteomic signatures found in these samples. This processed data is being derived by establishing standard data analysis workflows vetted by 114 scientists who are members of the four GeneLab Analysis Working Groups (Animal AWG, Plant AWG, Microbe AWG, Multi-Omics AWG). AWG members from institutes spanning the U.S. and four other countries participate on a voluntary basis. The AWGs meet monthly to discuss data mining, compare results and interpretations, and test forthcoming releases of the GeneLab Data Systems (GLDS). GLDS version 3.0 has been available to the general public since October 1st 2018, and has been providing a professional state-of-the-art bioinformatics platform for everyone in the space biology community to upload their data into a space biology omics data commons, to process their data with vetted standard workflows and to compare to existing analyses. The user interface for the platform is being designed to be accessible to a broad variety of users including those with limited bioinformatics experience, including high school and college students who can use it to learn about omics data analysis and space biology. As such, Genelab will constitute a powerful general public outreach capability of NASA and the Space Biology community at large. Data mining of the GeneLab database by the AWG has already started generating very interesting findings, including reports linking specific spaceflight conditions such as radiation, microgravity or carbon dioxide levels to molecular changes seen across various species. In this presentation, we will report on the current and future objectives for GeneLab, and review recent studies reported by the various AWGs relating molecular changes observed in various animal models and tissue with microgravity, radiation, circadian rhythm, hydration and carbon dioxide conditions.

Omics↗
NASA NTRS2018

UV Shielding of Bacillus pumilus SAFR-032 Endospores by Martian Regolith Simulants

As exploration of the solar system advances with life detection missions on the horizon, the concern for planetary protection has grown considerably. When attempting to detect extraterrestrial life, the likelihood of false positives from terrestrial contamination must be minimized. The Exposing Microorganisms in the Stratosphere (E-MIST) balloon project aims to evaluate whether resilient terrestrial bacteria can survive stressors in a Mars-like environment. This is accomplished by sending Bacillus pumilus SAFR-032, an endospore-forming bacterial isolate from a spacecraft assembly facility, to the Earth's middle stratosphere (30-38 kilometers), where low temperature and pressure and high radiation and dryness conditions are similar to the surface of Mars. Previous ground and flight tests showed that the vast majority of SAFR-032 spores (99.99 percent) were inactivated by direct sunlight due to ultraviolet (UV) radiation. This observation led us to explore the role of dust shielding in changing microbial survivorship outcomes. To determine the dust particle distributions and density for potentially shielding microbes from UV radiation, samples of a Martian dust simulant were mixed with SAFR-032 spores. The dry heat sterilized simulant used was JSC MARS-1, weathered volcanic ash from Hawaii that displays many chemical and physical properties similar to the Martian soil as characterized by the Viking Lander 1, including reflectance spectrum, chemical composition, mineralogy, grain size, specific gravity, and magnetic properties. First, scanning electron microscopy was undertaken to visualize the aggregation of the spores with dust particles (i.e., shading effects), and samples of varying dust concentrations were subsequently irradiated with UVC light to test survivorship outcomes. After a relationship between dust concentration and spore survivorship was determined, a solar simulator capable of irradiating samples with a fuller UV spectrum (less than 280-400 nanometers) was used to perform a more robust middle stratosphere simulation. Taken together, we will use results from the ground-based irradiation studies to feed into experimental designs for the next E-MIST ultra-long duration polar balloon flight launched by NASA.

Stratosphere↗
NASA NTRS2017

Stratosphere Conditions Inactivate Bacterial Endospores from a Mars Spacecraft Assembly Facility

Every spacecraft sent to Mars is allowed to land viable microbial bioburden, including hardy endospore-forming bacteria resistant to environmental extremes. Earth’s stratosphere is severely cold, dry, irradiated and oligotrophic; it can be used as a stand-in location for predicting how stowaway microbes might respond to the Martian surface. We launched E-MIST, a high altitude NASA balloon payload on 10 Oct 2015 carrying known quantities of viable Bacillus pumilus SAFR-032 (4.07 x107 spores per sample), a radiation-tolerant strain collected from a spacecraft assembly facility. The payload spent 8 hours at ~32 km above sea level exposing bacterial spores to the stratosphere. We found that within 120 and 240 min, spore viability was significantly reduced by 2 and 4 orders of magnitude, respectively. By 480 min, < 0.001% of spores carried to the stratosphere remained viable. Our balloon flight results predict that most terrestrial bacteria would be inactivated within the first Sol on Mars if contaminated spacecraft surfaces receive direct sunlight. Unfortunately, an instrument malfunction prevented the acquisition of ultraviolet (UV) light measurements during our balloon mission. To make up for the absence of radiometer data, we calculated a stratosphere UV model and also conducted ground tests with a 271.1 nm UVC light source (0.5 W/m2), observing a similarly rapid inactivation rate when using a lower number of contaminants (640 spores per sample). The starting concentration of spores and micro-configuration on hardware surfaces appeared to influence survivability outcomes in both experiments. With the relatively few spores that survived the stratosphere, we performed a re-sequencing analysis and identified 3 single nucleotide polymorphisms compared to unexposed controls. It is therefore plausible that bacteria enduring radiation-rich environments (e.g., Earth’s upper atmosphere, interplanetary space, or the surface of Mars) may be pushed in evolutionarily consequential directions.

Mars↗
NASA NTRS2019

MEDLI2 Flight Heat Flux Sensor Environment and Planetary Protection Testing

Mars 2020 will fly the Mars Entry, Descent, and Landing Instrumentation II (MEDLI2) sensor suite consisting of a total of seventeen instrumented thermocouple sensor plugs, eight pressure transducers, two total heat flux sensors, and one radiometer embedded in the thermal protection system (TPS). Of the MEDLI2 instrumentation, eleven instrumented thermocouple plugs and seven pressure transducers will be installed on the heatshield of the Mars 2020 vehicle while the rest will be installed on the backshell. The goal of the MEDLI2 instrumentation is to directly inform the large performance uncertainties that contribute to the design and validation of a Mars entry system. A better understanding of the entry environment and TPS performance could lead to reduced design margins enabling greater payload mass-fraction and smaller landing ellipses. The MEDLI2 total heat flux sensors and radiometer are new instruments that were not flown on the Mars Science Laboratory mission. These sensors directly measure the surface heat flux and radiation at specific backshell locations. The total heat flux sensors use a Schmidt-Boelter sensing element. The radiometer version uses a sapphire window placed over the Schmidt-Boelter sensing element to separate the radiative component of the total heat flux. MEDLI2 recently planned and executed protoflight environmental testing as well planetary protection measures on the flight and flight-spare total heat flux sensors and radiometers. This testing is required to provide confidence in the performance of the flight-lot sensors when exposed to flight-like environments, and to reduce the risk of biological contamination on the planet of Mars with microbes from Earth.

MEDLI2 FLIGHT HEAT FLUX SENSOR ENVIRONMENT AND PLA↗
NASA NTRS2019

GeneLab: A Systems Biology Platform for Omics Analysis: Disseminate and Reuse Data, Tools, and Samples Post-Project

NASA's GeneLab includes an open-access repository of some 200 plus omics datasets generated by biological experiments relevant to spaceflight (including simulated cosmic radiation and microgravity). In order to maximize the intelligibility of these data, particularly for users with limited bioinformatics knowledge, GeneLab is now transforming the data in the repository into actual biological and physiological knowledge of the genetic and proteomic signatures found in these samples. This processed data is being derived by establishing standard data analysis workflows vetted by 114 scientists who are members of the four GeneLab Analysis Working Groups (Animal AWG, Plant AWG, Microbe AWG, Multi-Omics AWG). AWG members from institutes spanning the U.S. and four other countries participate on a voluntary basis. The AWGs meet monthly to discuss data mining, compare results and interpretations, and test forthcoming releases of the GeneLab Data Systems (GLDS). GLDS version 3.0 has been available to the general public since October 1st 2018, and has been providing a professional state-of-the-art bioinformatics platform for everyone in the space biology community to upload their data into a space biology omics data commons, to process their data with vetted standard workflows and to compare to existing analyses. The user interface for the platform is being designed to be accessible to a broad variety of users including those with limited bioinformatics experience, including high school and college students who can use it to learn about omics data analysis and space biology. As such, Genelab will constitute a powerful general public outreach capability of NASA and the Space Biology community at large. Data mining of the GeneLab database by the AWG has already started generating very interesting findings, including reports linking specific spaceflight conditions such as radiation, microgravity or carbon dioxide levels to molecular changes seen across various species. In this presentation, we will report on the current and future objectives for GeneLab, and review recent studies reported by the various AWGs relating molecular changes observed in various animal models and tissue with microgravity, radiation, circadian rhythm, hydration and carbon dioxide conditions.

Omics↗
NASA NTRS2019

Does Seed Sanitization Affect the Plant Rhizosphere Microbiome and Its Ability to Compete with the Human Associated Pathogen, E. coli on Salad Crops?

Cultivation of crops in controlled environmental agricultural systems may limit microbial colonization and reduce diversity of the microbial communities. Practices like seed and growth medium sanitization may further impact microbial communities in the mature plant and the plant’s capacity to limit the growth of pathogens through competition. As humans expand their travels to space, understanding plant growth, health, and development in closed environments will be critical to the success of producing a safe, supplemental food source for astronauts. To determine the persistence of a potential human pathogen in plant growth and development, sanitized and unsanitized seeds from, mizuna (Brassica rapa var japonica) and red romaine lettuce (Lactuca sativa cultivar ‘Outredgeous’), were inoculated with Escherichia coli, ATCC 21445, germinated under simulated International Space Station (ISS) environmental conditions and harvested every 7 days until maturity. The persistence of E. coli in the rhizosphere was determined by plating on selective media, real time PCR (Polymerase Chain Reaction) and community sequencing of the rhizosphere communities. E. coli was detected in the crops’ roots and leaves for several weeks post germination. At day 28, plants from sanitized seeds had significantly higher counts of E. coli on the roots than those from unsanitized seeds. E. coli was also detected on a few uninoculated plants indicating airborne cross contamination among plants in the same growth chamber and suggesting an influence of the natural microbiome on human pathogen survival and persistence in leafy greens. Sequencing analysis revealed variations in composition and diversity between the communities. Understanding the microbial community of the rhizospheric microbiome is only the first step in determining the relationships between plants. Additional studies to include genotypic and phenotypic variations in the plants should be considered to determine if the natural microbes in the rhizosphere may contribute to the health and therefore, safety of the edible plants.

Khodadad, Christina L. M.↗