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At least 289 records · Page 16

Overview of Microbiological Tests Performed During the Design of the International Space Station Environmental Control and Life Support Systems

The design and manufacturing of the main Environmental Control and Life Support Systems (ECLSS) for the United States segments of the International Space Station (ISS) was an involved process that started in the late 1980's, with the assessment and testing of competing technologies that could be used to clean the air and recycle water. It culminated in 2009 with the delivery and successful activation of the Water Recovery System (WRS) water processor (WP). The ECLSS required the work of a team of engineers and scientist working together to develop systems that could clean and/or recycle human metabolic loads to maintain a clean atmosphere and provide the crew clean water. One of the main goals of the ECLSS is to minimize the time spent by the crew worrying about vital resources not available in the vacuum of space, which allows them to spend most of their time learning to live in a microgravity environment many miles from the comforts of Earth and working on science experiments. Microorganisms are a significant part of the human body as well as part of the environment that we live in. Therefore, the ISS ECLSS design had to take into account the effect microorganisms have on the quality of stored water and wastewater, as well as that of the air systems. Hardware performance issues impacted by the accumulation of biofilm and/or microbiologically influenced corrosion were also studied during the ECLSS development stages. Many of the tests that were performed had to take into account the unique aspects of a microgravity environment as well as the challenge of understanding how to design systems that could not be sterilized or maintained in a sterile state. This paper will summarize the work of several studies that were performed to assess the impacts and/or to minimize the effects of microorganisms in the design of a closed loop life support system.

Roman, Monsi C.↗

Psychrophilic Biomass Producers in the Trophic Chain of the Microbial Community of Lake Untersee, Antarctica

The study of photosynthetic microorganisms from the Lake Untersee samples showed dispersed distribution of phototrophs within ~80 m water column. Lake Untersee represents a unique ecosystem that experienced complete isolation: sealed by the Anuchin Glacier for many millennia. Consequently, its biocenosis has evolved over a significant period of time without exchange or external interaction with species from other environments. The major producers of organic matter in Lake Untersee are represented by phototrophic and chemolithotrophic microorganisms. This is the traditional trophic scheme for lacustrine ecosystems on Earth. Among the phototrophs, diatoms were not found, which differentiates this lake from other known ecosystems. The dominant species among phototrophs was Chlamydomonas sp. with typical morphostructure: green chloroplasts, bright red round spot, and two polar flagella near the opening. As expected, the physiology of studied phototrophs was limited by low temperature, which defined them as obligate psychrophilic microorganisms. By the quantity estimation of methanogenesis in this lake, the litho-autotrophic production of organic matter is competitive with phototrophic production. However, pure cultures of methanogens have not yet been obtained. We discuss the primary producers of organic matter and the participation of our novel psychrophilic homoacetogen into the litho-autotrophic link of biomass production in Lake Untersee.

Pikuta, Elena V.↗

Study of the Microbial Diversity of a Newly Discovered East Antarctic Freshwater Lake, L27C, and of a Perennially Ice-Covered Lake Untersee

The microbial communities that reside within freshwater lakes of Schirmacher and Untersee Oases in East Antarctica must cope with extreme conditions that may include cold temperature, annual freeze-thaw cycles, exposure to UV radiation, especially during the austral summer months, low light beneath thick ice-cover, followed by seasonal darkness. The objective of this study was to assess the microbial biodiversity and distribution from samples taken from two freshwater lakes (L27C and Lake Untersee) that were collected during the Tawani 2008 International Antarctic Expedition that conducted research in this region of Antarctica. L27C is a small, previously unreported lake residing 2 km WNW of Maitri Station at Schirmacher Oasis. Biodiversity and distribution of microorganisms within the lake were studied using both culture-independent and culture-dependent methodologies based upon the analysis of eubacterial 16S rRNA gene sequences. Lake Untersee, a perennially ice-covered, ultra-oligotrophic, lake in the Otto-von-Gruber-Gebirge (Gruber Mountains) of central Dronning Maud Land was also sampled and the microbial diversity was analyzed by eubacterial 16S rRNA gene sequences derived from pure cultures. Direct culturing of water samples from each lake on separate R2A growth medium exhibited a variety of microorganisms including: Janthinobacterium, Hymenobacter, Sphingamonas, Subtercola, Deinococcus, Arthrobacter, Flavobacterium, Polaromonas, Rhodoferax and Duganella. The evaluation of samples from L27C through culture-independent methodology identified a rich microbial diversity consisting of six different phyla of bacteria. The culture-independent analysis also displayed the majority of bacteria (56%) belonged to the Class gamma-proteobacteria within the phylum Proteobacteria. Within the Class gamma-proteobacteria, Acinetobacter dominated (48%) the total microbial load. Overall, L27C exhibited 7 different phyla of bacteria and 20 different genera. Statistical analysis (Shannon-Weaver Diversity Index and Simpson Diversity Index) of the biodiversity of L27C displayed a moderately rich and diverse community. Investigations of the biodiversity and distribution of microorganisms in these lakes will help further our understanding of how the physical environment impact the structure and function within these microbially dominated ecosystems.

Huang, Jonathan P.↗

Microbial Contamination in the Spacecraft

Spacecraft and space habitats supporting human exploration contain a diverse population of microorganisms. Microorganisms may threaten human habitation in many ways that directly or indirectly impact the health, safety, or performance of astronauts. The ability to produce and maintain spacecraft and space stations with environments suitable for human habitation has been established over 40 years of human spaceflight. An extensive database of environmental microbiological parameters has been provided for short-term (< 20 days) spaceflight by more than 100 missions aboard the Space Shuttle. The NASA Mir Program provided similar data for long-duration missions. Interestingly, the major bacterial and fungal species found in the Space Shuttle are similar to those encountered in the nearly 15-year-old Mir. Lessons learned from both the US and Russian space programs have been incorporated into the habitability plan for the International Space Station. The focus is on preventive measures developed for spacecraft, cargo, and crews. On-orbit regular housekeeping practices complete with visual inspections are essential, along with microbiological monitoring. Risks associated with extended stays on the Moon or a Mars exploration mission will be much greater than previous experiences because of additional unknown variables. The current knowledge base is insufficient for exploration missions, and research is essential to understand the effects of spaceflight on biological functions and population dynamics of microorganisms in spacecraft.

Pierson, Duane L.↗

Microbial Anomalies Encountered on the International Space Station

Microorganisms in our living environments are unavoidable. A community of microbes arrived in space with the delivery of the first element of the International Space Station (ISS), attached to hardware and on the bodies of the humans tasked with the initial assembly missions. The risk that microorganisms could cause adverse effects in the health of both the human occupants of the ISS as well as the physical integrity of the station environment and life support systems has been both a driver and a function of engineering and operational controls. Scientists and engineers at NASA have gone to extensive measures to control microbial growth at levels safe for the crewmembers and the spacecraft environment. Many of these measures were initiated with the design of the spacecraft and its systems. Materials used in the ISS were tested for resistance to fungi, such as mold and a paint with a fungus-killing chemical was also used. Controlling the humidity of the air in the Station is also an effective way of discouraging microbe growth. The breathing air is reconditioned by the Environmental Control Life Support System (ECLSS) prior to distribution, utilizing High Efficiency Particulate Air (HEPA) filtration. Requirements restricting the accumulation of water condensate in the air handlers and habitable volume of the ISS were other safeguards added. Water for drinking and food rehydration is disinfected or filtered. A robust in-flight housekeeping regimen for the ISS significantly reduces inappropriate growth of microorganisms and includes a regular cleaning of accessible surfaces with disinfectant wipes. Most of these requirements were suggested by microbiologists to mitigate and possibly prevent many microbiological risks. In addition to these controls, before flight monitoring and analyses of the cabin air, exposed surfaces, water and food, consumables, and crew members are conducted to mitigate microbial risk to the crew and spacecraft. Many microbial risks are much easier to identify and resolve before launch than during space flight. Although the focus has been on prevention of microbiologically related, not all problems can be anticipated. A number of microbial anomalies have occurred on ISS. This paper will discuss the occurrences, root-cause investigations, and mitigation steps taken to remediate the contamination.

Bruce, Rebekah J.↗

The Biotoxicity of Mars Soils

Recent evidence from the Opportunity and Spirit rovers suggests that the soils on Mars might be very high in biotoxic materials induding sulfate salts, chlorides, and acidifying agents. Yet, very little is known about how the chemistries of Mars soils might affect the survival and growth of terrestrial microorganisms. The primary objectives of the proposed research will be to: (1) prepare and characterize Mars analog soils amended with potential biotoxic levels of sulfates, chlorides, and acidifying minerals; (2) use the stimulants to conduct a series of toxicology assays to determine if terrestrial microorganisms from spacecraft or extreme environments can survive direct exposure to the biotoxic soils, and (3) mix soils from extreme environments on Earth into Mars analog soils to determine if terrestrial microorganisms can grow and replicate under Martian conditions. The Mars analog soils will be thoroughly characterized by a wide diversity of soil chemistry assays to determine the exact nature of the soluble biotoxic components following hydration. The microbial experiments will be designed to test the effects of Mars stimulants on microbial survival, growth and replication during direct challenge experiments. Toxicology experiments will be designed to mimic terrestrial microbes coming into contact with biotoxic soils with and without liquid water. Results are expected to help" ... characterize the limits of life in ... planetary environments ... " and may help constrain the search for life on Mars.

Kerney, Krystal↗

Monitoring of Microbial Loads During Long Duration Missions as a Risk Reduction Tool

Humans have been exploring space for more than 40 years. For all those years microorganisms have accompanied, first un-manned spacecraft/cargo and later manned vessels. Microorganisms are everywhere on Earth, could easily adapt to new environments and/or can rapidly mutate to survive in very harsh conditions. Their presence in spacecraft and cargo have caused a few inconveniences over the years of humans spaceflight, ranging from crew health, life support systems challenges and material degradation. The sterilization of spacecraft that will host humans in long duration mission would be a costly operation that will not provide a long-term solution to the microbial colonization of the vessels. As soon as a human is exposed to the spacecraft, during the mission, microorganisms will start to populate the new environment. As the hum an presence in space increases in length, the risk from the microbial load, to hardware and crew will also increase. Mitigation of this risk includes several different strategies that will include minimizing the microbial load (in numbers and diversity) and monitoring. This presentation will provide a list of the risk mitigation strategies that should be implemented during ground processing, and during the mission. It will also discuss the areas that should be discussed before an effective in-flight microbial monitoring regimen is implemented. Microbial monitoring technologies will also be presented.

Roman, Monsi C.↗

Extreme Ionizing-Radiation-Resistant Bacterium

There is a growing concern that desiccation and extreme radiation-resistant, non-spore-forming microorganisms associated with spacecraft surfaces can withstand space environmental conditions and subsequent proliferation on another solar body. Such forward contamination would jeopardize future life detection or sample return technologies. The prime focus of NASA s planetary protection efforts is the development of strategies for inactivating resistance-bearing micro-organisms. Eradi cation techniques can be designed to target resistance-conferring microbial populations by first identifying and understanding their physiologic and biochemical capabilities that confers its elevated tolerance (as is being studied in Deinococcus phoenicis, as a result of this description). Furthermore, hospitals, food, and government agencies frequently use biological indicators to ensure the efficacy of a wide range of radiation-based sterilization processes. Due to their resistance to a variety of perturbations, the nonspore forming D. phoenicis may be a more appropriate biological indicator than those currently in use. The high flux of cosmic rays during space travel and onto the unshielded surface of Mars poses a significant hazard to the survival of microbial life. Thus, radiation-resistant microorganisms are of particular concern that can survive extreme radiation, desiccation, and low temperatures experienced during space travel. Spore-forming bacteria, a common inhabitant of spacecraft assembly facilities, are known to tolerate these extreme conditions. Since the Viking era, spores have been utilized to assess the degree and level of microbiological contamination on spacecraft and their associated spacecraft assembly facilities. Members of the non-sporeforming bacterial community such as Deinococcus radiodurans can survive acute exposures to ionizing radiation (5 kGy), ultraviolet light (1 kJ/m2), and desiccation (years). These resistive phenotypes of Deinococcus enhance the potential for transfer, and subsequent proliferation, on another solar body such as Mars and Europa. These organisms are more likely to escape planetary protection assays, which only take into account presence of spores. Hence, presences of extreme radiation-resistant Deinococcus in the cleanroom facility where spacecraft are assembled pose a serious risk for integrity of life-detection missions. The microorganism described herein was isolated from the surfaces of the cleanroom facility in which the Phoenix Lander was assembled. The isolated bacterial strain was subjected to a comprehensive polyphasic analysis to characterize its taxonomic position. This bacterium exhibits very low 16SrRNA similarity with any other environmental isolate reported to date. Both phenotypic and phylogenetic analyses clearly indicate that this isolate belongs to the genus Deinococcus and represents a novel species. The name Deinococcus phoenicis was proposed after the Phoenix spacecraft, which was undergoing assembly, testing, and launch operations in the spacecraft assembly facility at the time of isolation. D. phoenicis cells exhibited higher resistance to ionizing radiation (cobalt-60; 14 kGy) than the cells of the D. radiodurans (5 kGy). Thus, it is in the best interest of NASA to thoroughly characterize this organism, which will further assess in determining the potential for forward contamination. Upon the completion of genetic and physiological characteristics of D. phoenicis, it will be added to a planetary protection database to be able to further model and predict the probability of forward contamination.

Vaishampayan, Parag A.↗

Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions

Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25 degrees C for 24 hr within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 hr of exposure to Mars-normal conditions of 4.55 W/m(2) UVC irradiation (200-280 nm), -12.5 degrees C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H(2)O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at tau = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 hr exposure period.

Smith, David J.↗

Standardization of Spore Inactivation Method for PMA-PhyloChip Analysis

In compliance with the Committee on Space Research (COSPAR) planetary protection policy, National Aeronautics and Space Administration (NASA) monitors the total microbial burden of spacecraft as a means for minimizing the inadvertent transfer of viable contaminant microorganisms to extraterrestrial environments (forward contamination). NASA standard assay-based counts are used both as a proxy for relative surface cleanliness and to estimate overall microbial burden as well as to assess whether forward planetary protection risk criteria are met for a given mission, which vary by the planetary body to be explored and whether or not life detection missions are present. Despite efforts to reduce presence of microorganisms from spacecraft prior to launch, microbes have been isolated from spacecraft and associated surfaces within the extreme conditions of clean room facilities using state of the art molecular technologies. Development of a more sensitive method that will better enumerate all viable microorganisms from spacecraft and associated surfaces could support future life detection missions. Current culture-based (NASA standard spore assay) and nucleic-acid-based polymerase chain reaction (PCR) methods have significant shortcomings in this type of analysis. The overall goal of this project is to evaluate and validate a new molecular method based on the use of a deoxyribonucleic acid (DNA) intercalating agent propidium monoazide (PMA). This is used in combination with DNA microarray (PhyloChip) which has been shown to identify very low levels of organisms on spacecraft associated surfaces. PMA can only penetrate the membrane of dead cells. Once penetrated, it intercalates the DNA and, upon photolysis using visible light it produces stable DNA monoadducts. This allows DNA to be unavailable for further PCR analysis. The specific aim of this study is to standardize the spore inactivation method for PMA-PhyloChip analysis. We have used the bacterial spores Bacillus subtilis 168 (standard laboratory isolate) as a test organism.

spore inactivation↗

Establishing and Monitoring an Aseptic Workspace for Building the MOMA Mass Spectrometer

Mars Organic Molecule Analyzer (MOMA) is an instrument suite on the European Space Agency (ESA) ExoMars 2020 Rover, and the Mass Spectrometer (MOMA-MS) is being built at Goddard Space Flight Center (GSFC). MOMA-MS is a life-detection instrument and thus falls in the most stringent category of Planetary Protection (PP) biological cleanliness requirements. Less than 0.03 spore/m2 are allowed in the instrument sample path. In order to meet these PP requirements, MOMA-MS must be built and maintained in a low bioburden environment. The MOMA-MS project at GSFC maintains three clean rooms with varying levels of bioburden control. The Aseptic Assembly Clean room has the highest level of control, applying three different bioburden reducing methods: 70% Isopropyl Alcohol (IPA), 7.5% Hydrogen Peroxide, and Ultra-Violet C (UVC) light. The three methods are used in rotation and each kills microorganisms by a different mechanism, reducing the likelihood of microorganisms developing resistance to all three. The Integration and Mars Chamber Clean rooms use less biocidal cleaning, with the option to deploy extra techniques as necessary. To support the monitoring of clean rooms and verification that MOMA-MS hardware meets PP requirements, a new Planetary Protection lab was established that currently has the capabilities of standard growth assays for spore or vegetative bacteria, rapid bioburden analysis that detects Adenosine Triphosphate (ATP), plus autoclave and Dry Heat microbial Reduction (DHMR) verification. The clean rooms are monitored for vegetative microorganisms and by rapid ATP assay, and a clear difference in bioburden is observed between the aseptic and other clean room.

Contamination Control Engineering↗

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.↗

Establishing and Monitoring an Aseptic Workspace

When are aseptic operations necessary? In order to meet certain bioburden requirements, some components must undergo dry heat microbial reduction (DHMR) or other sterilizing procedures. If sensitive surfaces must be re-exposed after DHMR, this could compromise the bioburden levels. Recontaminating sterilized surfaces could be costly both in time by requiring repeated DHMR and risk to the hardware, which may not be compatible with repeated high temperature bakes. In order to prevent recontamination of the sensitive surfaces, an aseptic environment and sterile technique must be employed. Aseptic environments mean working in a space with almost no detectable bioburden in the air or on surfaces. Ideally, DHMR happens as late as possible to avoid requiring aseptic operations, as it can be considered a high-risk operations. Preparing the cleanroom for aseptic operations Establishing an ISO (International Organization for Standardization) class 5 space to minimize airborne particles. Maintain low bioburden in the cleanroom by using biocidal cleaners. Using multiple biocidal techniques decreases the likelihood of selecting for resistant microorganisms. 70% Isopropyl Alcohol (IPA) denatures the proteins in a microorganism (note: 70% IPA is better at killing microorganisms than 100% IPA) 7% hydrogen peroxide: damages DNA and proteins through oxygen radical damage. Ultraviolet-C (UV-C) lamps: causes crosslinking in DNA which prevents replication. Monitor cleanroom regularly for bioburden trending: Standard bioassay: Swab or wipe samples of cleanroom surfaces processed for colony forming unity (viable or spore selected); Rapid bioassay: Adenosine triphosphate (ATP) or Limulus amebocyte lysate (LAL) for a bioburden snapshot. High levels can signal an immediate re-cleaning before standard bioassay samples are taken. Airborne monitoring: Active (pulling air through a filter) or passive (particle fallout) for bioburden. Verify bioburden levels just before aseptic operation. Test hardware and cleanroom surfaces and air 3 days before the planned aseptic operation. Rapid bioburden just before aseptic operation to ensure room was not re-contaminated. Preparing personnel and tools: Personnel training. Everyone in the cleanroom: Standard cleanroom certification Everyone on the team: 1 day Planetary Protection overview. Aseptic operators only: Half-day aseptic operations training. Covers sterile garmenting/gloves, Sterile handling with a focus on contact transfer risk, tool/GSE preparation, and two-operator system for opening sterilized tools/components. Tool sterilization: All tools to be used during an aseptic operation need to be identified. Compatible tools are sterilized by DHMR or Autoclave. Double wrapped so that the exterior bag can be handled by a non-sterile operator, and the sterile. Tools that are not compatible with high heat do not come in contact with sensitive surfaces: either substitutes are found, or tools are isolated by wrapping in sterile foil. During an aseptic operation. Pre-task to make sure everyone understands the operations, who is handling what, and when the most critical surfaces will be exposed. Monitoring during the operation. Bioburden: active and passive airborne bioburden sampling, glove-tip dabs onto a plate after completion of operation (3 days for results). Particles: real time particle counter constantly running, with alarm for exceeding ISO 5 conditions.

aseptic processing↗

BioNutrients-2: Improvements to the BioNutrients-1 Nutrient Production System

The BioNutrients (BN) project aims to develop an on-demand nutrient production system capable of rapid and safe delivery of multiple nutrients in a single-use production pack for long-duration missions. The general concept of this system will be to develop an edible engineered microorganism capable of surviving during long-term storage, revival and growth of that microorganism for product production, and delivery of precise quantities of nutrients for human consumption. BN-1 is a five-year flight project currently on the International Space Station (ISS). It is testing the long-term storage of various microorganisms for the biomanufacturing of space relevant compounds and to validate the performance of the first generation (Gen-1) of production packs. The BN-2 project is a continuation of the BN-1 flight project and intends to expand the projects overall scope by introducing novel products, broadening the range of microbial food sources, and improving previously designed hardware from the BN-1 project. We are in the process of optimizing our platform biomanufacturing technology for in situ production of yogurt and kefir on the ISS. BN-2 will test the efficacy of this technology for future delivery of probiotic organisms which can be engineered to produce additional nutritional supplements (consumption by the crew is not planned in this project). Furthermore, to improve the feasibility of this technology for mission use we have transitioned from a hard-shell pack to a Gen-2, fluorinated ethylene propylene (FEP) bag. The single-use FEP bioreactor will facilitate growth of known organisms and ensure a contaminant free environment, while reducing mass and volume. These bioreactors will be employed for production of additional space relevant products in the BN-2 project. On-orbit testing of Gen-2 production packs will be necessary for future iterations, in order to optimize bag design and product production for eventual flight use by the crew.

BioNutrients↗

BioNutrients-2: Improvements to the BioNutrients-1 Nutrient Production System

The BioNutrients (BN) project aims to develop an on-demand biological production system capable of rapid and safe delivery of multiple nutrients in single-use production packs for long-duration missions. The general concept of this system is to develop edible engineered microorganisms that produce nutrients for human consumption following long-term storage, revival, and growth. BN-1 is a five-year flight project currently on the International Space Station (ISS). It is testing the long-term storage of various microorganisms for the biomanufacturing of space-relevant compounds and validating the performance of the first generation of production packs. The BN-2 project expands the BN-1 flight project scope by introducing novel products, broadening the range of microbial food sources, and improving upon production pack hardware. We are optimizing the biomanufacturing platform for in situ production of yogurt and kefir on the ISS. BN-2 also will test engineered microorganisms, including a probiotic strain, to produce carotenoids or follistatin. To improve the feasibility of this technology for mission use, we transitioned from a hard-shell pack to a second-generation fluorinated ethylene propylene (FEP) bag. The single-use FEP bioreactor facilitates growth of target organisms in a contaminant free environment, while reducing mass and volume compared to the BN-1 hardware. These bioreactors will be employed for production of additional space-relevant products in the BN-2 project. On-orbit testing of FEP production packs will enable optimization of the platform for eventual flight use by the crew.

Natalie Ball↗

BioNutrients: Microbial on-demand production of short shelf-life micronutrients in space

Long duration deep space missions pose a significant challenge when considering adequate nutrition for human spaceflight. Many micronutrients supplied in pre-packaged foods for low Earth orbit flights have a short shelf life and will degrade over multi-year missions. One strategy to mitigate the risk of micronutrient malnutrition is to grow fresh foods to supplement a pre-packaged diet. The BioNutrients project aims to develop systems for growing edible microorganisms that are genetically engineered to produce short shelf life micronutrients. BioNutrients-1 (BN-1) is a five-year spaceflight project currently underway on the International Space Station (ISS) that tests long-term storage and production of two carotenoids, β-carotene and zeaxanthin, in genetically engineered yeast strains. BN-1 on-orbit and ground control activities indicate that the nutrient production system will be stable for at least two years in ambient storage conditions. BN-1 is also testing the effects of long-term ISS storage on viability and gene expression using “stasis packs” containing a series of microorganisms useful in food and biomanufacturing processes. Stasis pack analysis is distinguishing microorganisms with full viability after two years of storage from other species that lose viability rapidly. In parallel, BioNutrients-2 (BN-2) is being developed as a six-month flight experiment that will expand the range of foods produced on ISS to include yogurt, kefir, and probiotic yeast. BN-2 will improve upon hardware design by transitioning from a hard-shell polycarbonate bioreactor to a flexible fluorinated ethylene propylene (FEP) bag. This change reduces the mass and volume required to store production packs. The long-term goal of BioNutrients is to develop the capability for rapid and safe delivery of multiple micronutrients in single-use production packs. We expect synthetic biology approaches similar to BioNutrients will play an important role for astronaut health in future NASA missions to the Moon and Mars.

Synthetic Biology↗

Spaceflight-induced Changes in Microbial Virulence and the Impact to the Host Immune Response

INTRODUCTION Over the past 50 years, many microorganisms have displayed unexpected responses relevant to infectious disease when grown in microgravity and microgravity analogue environments, including changes in stress resistance, biofilm production, antibiotic sensitivity, final cell concentration, gene expression, enhanced host-pathogen interaction, and virulence. In parallel, astronaut studies have characterized a persistent spaceflight-induced dysregulation of the human immune system; consisting of altered leukocyte distribution, reductions in T and NK cell function, altered cytokine profiles, and reactivation of latent herpesviruses. Further, astronauts have some degree of clinical incidence, primarily infectious disease episodes and atopic dermatitis. The impact of the microgravity environment on host-pathogen interactions and potential for clinical disease remains understudied and poorly characterized. SPECIFIC AIMS In this study, the following Specific Aims are being investigated, using the microbial pathogens, Salmonella enterica Enteritidis, Pseudomonas aeruginosa, Burkholderia cepacia, Streptococcus pneumoniae, and enterohemorrhagic Escherichia coli (EHEC). Aim 1: Characterize the effect of spaceflight analogue culture on microbial pathogenesis-related stress responses and in vitro host-pathogen interactions. Analyses include microbial stress responses as well as colonization and viability following pathogen challenge of three-dimensional (3-D) tissue co-culture models containing immune cells. We specifically selected obligate and opportunistic pathogens that are medically important and have been or are likely to be found aboard spacecraft. Aim 2: Characterize the effect of spaceflight analogue culture on the virulence potential of pathogenic microorganisms. Virulence will be assessed using a mouse model of infection. SIGNIFICANCE The goal of this study is to use spaceflight analogue conditions to gain insight into the breadth of medically-significant International Space Station microorganisms that have altered virulence and the impact of those changes on the immune response of the host. This information will provide critical understanding into the impact of microgravity on potential alterations in microbial virulence and associated infectious disease risk to crew health during spaceflight missions.

C M Ott↗

Molecular Identification of Microbial Contaminants

Microorganisms can have significant impacts on the success of NASA’s missions, including the integrity of materials, the reliability of scientific results, and maintenance of crew health. Robust cleaning and sterilization protocols are currently in place in NASA facilities, but agency experts agree that microbial contamination is unavoidable and its impact on NASA’s missions and science must be minimized. Therefore, it is critical to understand: 1) what specific microorganisms are present, 2) how they may impact scientific objectives, and 3) how to select appropriate mitigation strategies. The Marshall Space Flight Center (MSFC) Planetary Protection (PP) microbiology lab historically relied solely upon enumeration of culturable microbial contamination associated with spacecraft materials or cleanrooms. However, this process is time consuming, many microbes cannot be cultured, and very few can be identified with any fidelity using NASA standard microbiological methods. The work described in this white paper includes the establishment of molecular identification capabilities at MSFC, including DNA isolation, amplification, purification, and Sanger sequencing. This capability will not only improve planetary protection efforts at MSFC (i.e. by identifying contaminating microorganisms in cleanrooms or on spacecraft) but also offers a service center-wide for the identification of contaminants that arise in other projects, processing locations, or during set up and roll out of spacecraft. This work also lays the foundation for higher throughput efforts to identify large populations of microbes across the lifetime of a project and serves as the starting point for future work into whole genome sequencing, non-culture based methods, or additional characterization studies. Ultimately, accurate identification informs appropriate mitigation strategies, increasing the chances of success for NASA’s missions and objectives.

C. D. Cassilly↗