The safety of the International Space Station (ISS) crewmembers and maintenance of ISS hardware are the primary rationale for monitoring microorganisms in this closed habitat. The composition of the microbial community of this built environment is unique due to microgravity space radiation and elevated carbon dioxide levels. As built environments are known to have their own microbiomes next-generation sequencing methods have to be utilized to explore the ISS microbial profile and use this data for further development of safety and maintenance practices. ISS vacuum cleaner bag components (surface) and high-efficiency particulate arrestance (HEPA) filter element (air) samples were analyzed by traditional cultivation adenosine triphosphate (ATP) and propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) assays to estimate viable microbial populations. In addition vacuum cleaner bag components of two cleanrooms at Jet Propulsion Laboratory (JPL Pasadena CA) were examined concurrently. The 16S rRNA gene sequencing based on Illumina platform was used to elucidate the ISS microbial diversity and explore differences between the microbiomes of the ISS and Earth-based cleanrooms. The statistical analyses of these microbiomes show that Actinobacteria Firmicutes and Proteobacteria dominate in the air and surface of the ISS and the cleanroom samples but vary in abundance. While members of Actinobacteria were predominant in the ISS Proteobacteria the least abundant phylum in the ISS dominated the Earth-based cleanrooms. The viable bacterial population (PMA-treated samples) decreased significantly but the treatment did not appear to have an effect on the bacterial composition (diversity) associated with a sampling site. Viable fungal sequences were not retrieved from the ISS HEPA sample where as highest viable fungal diversity was observed in the Earth-based cleanroom (JPL class 100K) debris. The results of this study provided strong evidence of substantial contribution of human skin-associated microorganisms such as Corynebacterium/Propionibacterium (Actinobacteria),not Staphylococcus (Firmicutes) species as the dominant species in the ISS in terms of viable and total bacterial community structure.

The safety of the International Space Station (ISS) crewmembers and maintenance of ISS hardware are the primary rationale for monitoring microorganisms in this closed habitat. The composition of the microbial community of this built environment is unique due to microgravity space radiation and elevated carbon dioxide levels. As built environments are known to have their own microbiomes next-generation sequencing methods have to be utilized to explore the ISS microbial profile and use this data for further development of safety and maintenance practices. ISS vacuum cleaner bag components (surface) and high-efficiency particulate arrestance (HEPA) filter element (air) samples were analyzed by traditional cultivation adenosine triphosphate (ATP) and propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) assays to estimate viable microbial populations. In addition vacuum cleaner bag components of two cleanrooms at Jet Propulsion Laboratory (JPL Pasadena CA) were examined concurrently. The 16S rRNA gene sequencing based on Illumina platform was used to elucidate the ISS microbial diversity and explore differences between the microbiomes of the ISS and Earth-based cleanrooms. The statistical analyses of these microbiomes show that Actinobacteria Firmicutes and Proteobacteria dominate in the air and surface of the ISS and the cleanroom samples but vary in abundance. While members of Actinobacteria were predominant in the ISS Proteobacteria the least abundant phylum in the ISS dominated the Earth-based cleanrooms. The viable bacterial population (PMA-treated samples) decreased significantly but the treatment did not appear to have an effect on the bacterial composition (diversity) associated with a sampling site. Viable fungal sequences were not retrieved from the ISS HEPA sample where as highest viable fungal diversity was observed in the Earth-based cleanroom (JPL class 100K) debris. The results of this study provided strong evidence of substantial contribution of human skin-associated microorganisms such as Corynebacterium/Propionibacterium (Actinobacteria),not Staphylococcus (Firmicutes) species as the dominant species in the ISS in terms of viable and total bacterial community structure.

The objective of the Rodent Research-9 (RR-9) mission was to use mice to understand the molecular basis of phenomena that affect astronauts during long-duration spaceflight particularly visual impairment and joint tissue degradation. To this end a flight group (FLT) of 10-week-old male C57BL/6J mice was launched from Kennedy Space Center (KSC) on 8/14/2017 and housed in Rodent Habitats on the ISS for 33 days before being returned alive to Earth. After splashdown in the Pacific Ocean the animals were transported to Loma Linda University (LLU) for testing euthanasia and dissection on 9/18/2018. A Basal Control (BSL) was housed in standard cages at Kennedy Space Center (KSC) and euthanized one day after launch of the FLT animals (8/15/2017). Ground Control (GC) and Vivarium Control (VIV) studies were planned to commence at KSC approximately one-week after the conclusion of the flight experiments. However all the GC and VIV mouse studies at KSC had to be cancelled due to Hurricane Irma and potential adverse effects on the animal housing facility. The GC and VIV studies were therefore rescheduled and begun in May 2018. The GC was euthanized and dissected 6/18/2018 - 6/20/2018 while the VIV was euthanized and dissected 6/22/2018 - 6/23/2018. Because this resulted in a different cohort of mice being used for the GC and VIV controls as compared to the flight (FLT) and basal (BSL) groups two cohort controls were included in the study. The first Cohort Control 1 (CC_C1) was from the same cohort as the FLT and BSL animals and was sacrificed and dissected 4 days after the FLT group (9/22/2017). The second Cohort Control 2 (CC_C2) was from the same cohort as the GC and VIV animals and was sacrificed and dissected 2-8 days after the GC and VIV groups (6/24/2018 - 6/26/2018). The CC_C1 and CC_C2 groups were housed in standard cages and fed standard chow in contrast to all other groups which received Rodent Foodbars. To clarify the connections between treatment groups and animal cohorts the following group abbreviations are used in the sample metadata: Flight (FLT_C1); Basal (BSL_C1); Ground Control (GC_C2); Vivarium Control (VIV_C2) Cohort Control 1 (CC_C1); Cohort Control 2 (CC_C2). Fecal pellets were isolated directly from mice during dissection and preserved by flash freezing in liquid nitrogen before stored at -80 C. DNA was then extracted shotgun metagenomic libraries generated and libraries sequenced (target 10 M clusters at PE 250 bp). Metagenomic data was generated from the following groups: Basal Control (n=5) Ground Control (n=5) Vivarium Control (n=5) Cohort Control 1 (n=5) Cohort Control 2 (n=5) Flight (n=5).

Presented here is the environmental microbiome study of the International Space Station surfaces. The environmental samples were collected with the polyester wipes from eight different locations in the ISS during two consecutive sampling sessions (three months apart). The specific objective was to unveil the pool of genes for each location during two separate sessions to learn of functional and metabolic diversity of microorganisms in the ISS. The International Space Station (ISS) as a closed built environment has its own environmental microbiome which is shaped by microgravity, radiation, and limited human presence. The microbial diversity associated with ISS environmental surfaces was investigated during this study. Polyester wipes and contact slides were used for sampling of eight various surface locations on the ISS at different time periods. The samples were retrieved and analyzed immediately upon the return to the Earth (via Soyuz TMA-14M or Dragon capsule from SpaceX). After surface sample collection, contact slides containing nutrient media for the growth of bacteria and fungi were incubated at 25C. The polyester wipes were processed to measure microbial burden (R2A, Blood Agar, and Potato Dextrose Agar) and recover cultivable bacteria as well as fungi. Subsequently, viable microbial burden was assessed using Adenosine Triphosphate (ATP) assay, and quantitative polymerase chain reaction (PCR) methods after propidium monoazide (PMA) treatment. The 16S-tag and metagenome analyses were used to elucidate viable microbial diversity. The cultivable bacterial population yield from the polyester wipes was very high (5 to 7-logs) when compared with the contact slides (10^2 to 10^3 CFU/m2). The PMA-qPCR analysis showed considerable variation of viable bacterial population (10^5 to 10^9 16S rDNA gene copies/m2) among locations sampled. Unlike contact slides, polyester wipes cover much larger sample surface (~1 m2) and produce much more reliable results of the microbial diversity of the ISS covering both cultivable and non-cultivable species. The cultivable, total, and viable microbial diversity was determined utilizing state-of-the art molecular techniques. The implementation of the PMA assay before DNA extraction allowed distinguishing viable microorganisms, which is crucial for determining their role to the crew health, the ISS maintenance and the general knowledge of the closed environmentally controlled built systems.

This study s goal was to examine if any salivary microbiome changes were observed in astronauts as a result of spaceflight. In addition this study looked for any microbiome signature that may be associated with viral reactivation in humans

['16S sequencing of 15 swabs from the International Space Station']

Data were generated as part of a NASA-funded study (Turek F (PI) et al. Effects of Spaceflight on Gastrointestinal Microbiota in Mice: Mechanisms and Impact on Multi-System. NASA NRA: NRA NNH14ZTT002N). As part of the study we requested and received samples from RR1. We generated 16S rRNA gene amplicon sequence data from DNA extracted from fecal samples and compared these data to similar data generated on shuttle mission STS-135 and from ground-based studies of radiation. We assessed effect of flight conditions and radiation.

Results from C-20A science flights (30 October to 2 November 2017) collecting airborne microorganisms in the troposphere and lower stratosphere.

The International Space Station (ISS) is a unique habitat for humans and microorganisms. Here, we report the results of the ISS experiment EXTREMOPHILES, including the analysis of microbial communities from several areas aboard at three time points. We assess microbial diversity, distribution, functional capacity and resistance profile using a combination of cultivation-independent analyses (amplicon and shot-gun sequencing) and cultivation-dependent analyses (physiological and genetic characterization of microbial isolates, antibiotic resistance tests, co-incubation experiments). We show that the ISS microbial communities are highly similar to those present in ground-based confined indoor environments and are subject to fluctuations, although a core microbiome persists over time and locations. The genomic and physiological features selected by ISS conditions do not appear to be directly relevant to human health, although adaptations towards biofilm formation and surface interactions were observed. Our results do not raise direct reason for concern with respect to crew health, but indicate a potential threat towards material integrity in moist areas.

The introduction of generally recognized as safe (GRAS) probiotic microbes into the spaceflight food system has the potential for use as a safe non-invasive daily countermeasure to crew microbiome and immune dysregulation. However the microgravity effects on the stress tolerances and genetic expression of probiotic bacteria must be determined to confirm translation of strain benefits and to identify potential for optimization of growth survival and strain selection for spaceflight. The work presented here demonstrates the translation of characteristics of a GRAS probiotic bacteria to a microgravity analog environment. Lactobacillus acidophilus ATCC 4356 was grown in the low shear modeled microgravity (LSMMG) orientation and the control orientation in the rotating wall vessel (RWV) to determine the effect of LSMMG on the growth survival through stress challenge and gene expression of the strain. No differences were observed between the LSMMG and control grown L. acidophilus suggesting that the strain will behave similarly in spaceflight and may be expected to confer Earth-based benefits.