Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “MICROBIOME”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

Unlocking the Spacecraft and Human Habitat Microbiome to Enable the Next Generation of Space Exploration

Planetary protection is the discipline that prevents harmful contamination of the solar system during exploration activities. The current international guidelines and NASA policy addressing biological contamination on spacecraft surfaces contains prescriptive guidelines of spore requirements (e.g., 300 spores/m2, 5×105 spores per spacecraft) applicable to spacecraft bound for Mars. To verify these requirements spacecraft engineers sample spacecraft surfaces throughout the assembly, test and launch operations phase of the mission using damp water cotton swabs and polyester wipes. After sampling, the potential biological contamination is enumerated using a series of traditional microbiology techniques to include sonication, heat shocking at 80°C for 15min to select for spores, and growth on tryptic soy agar at 32°C for 72 hours. To enable crewed missions to Mars and robotic exploration of the Ocean Worlds a risk informed decision making / performance-based approach to assess biological contamination offers a promising solution in the trade space. Recognizing the need for a performance-based approach, NASA’s new Planetary Protection policies now incorporate the agility for missions to be able to leverage a performance or prescriptive approach. One of top contenders in the option space is a coupled quantitative, descriptive and functional based approach to be able to assess the quantity, types and capabilities of the biological contamination present on spacecraft surfaces. A tailored, mission by mission assurance case could then be formulated by building an argument around the target body, projected capabilities surrounding the types of organisms their potential for survival and proliferation, and ability to be transported on the target body to contaminate an area of biological interest. A performance-based requirement would then be used to demonstrate the mission’s compliance in protecting the planetary environment safety objectives. This symposium talk will showcase the background and need case for NASA to develop such a capability as well as provide an update on the efforts underway in developing a transparent and responsible performance-based approach to biological contamination assessments on spacecraft surfaces.

Habitat Microbiome↗
DOE OSTI2015

The Microbiome Project: Dogs

Dr. Jack Gilbert explains how having a dog could be good for your health thanks to bacteria.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Nitrogen enrichment suppresses other environmental drivers and homogenizes salt marsh leaf microbiome

Microbial community assembly is affected by a combination of forces that act simultaneously, but the mechanisms underpinning their relative influences remain elusive. This gap strongly limits our ability to predict human impacts on microbial communities and the processes they regulate. Here, we experimentally demonstrate that increased salinity stress, food web alteration and nutrient loading interact to drive outcomes in salt marsh fungal leaf communities. Both salinity stress and food web alterations drove communities to deterministically diverge, resulting in distinct fungal communities. Increased nutrient loads, nevertheless, partially suppressed the influence of other factors as determinants of fungal assembly. Using a null model approach, we found that increased nutrient loads enhanced the relative importance of stochastic over deterministic divergent processes; without increased nutrient loads, samples from different treatments showed a relatively (deterministic) divergent community assembly whereas increased nutrient loads drove the system to more stochastic assemblies, suppressing the effect of other treatments. These results demonstrate that common anthropogenic modifications can interact to control fungal community assembly. As a result, our results suggest that when the environmental conditions are spatially heterogeneous (as in our case, caused by specific combinations of experimental treatments), increased stochasticity caused by greater nutrient inputs can reduce the importance of deterministic filters that otherwise caused divergence, thus driving to microbial community homogenization.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Xanthohumol Microbiome and Signature in Healthy Adults (the XMaS Trial): Safety and Tolerability Results of a Phase I Triple-Masked, Placebo-Controlled Clinical Trial

Scope Xanthohumol, a prenylflavonoid from hops, has been extensively studied preclinically but has undergone limited research in human subjects. A triple-masked, placebo-controlled phase I clinical trial was conducted to examine the safety and tolerability of xanthohumol. Methods and results Thirty healthy volunteers were randomized to 24?mg/day xanthohumol (99.8% pure) or placebo for eight weeks. Comprehensive metabolic panels, complete blood counts, body weight, vital signs, and health-related quality of life questionnaires were assessed every two weeks. Participants were interviewed for adverse events (AEs) throughout the trial. Thirteen of 14 (93%) and 14 of 16 (88%) participants completed the trial in Group A and B respectively. There were no withdrawals due to AEs. There were no clinically relevant, between-group differences in laboratory biomarkers, body weight, vital signs, or health-related quality of life. There were no severe or FDA-defined serious AEs, but non-serious AEs were documented in both Group A (n=42) and Group B (n=58). Conclusion Over an eight-week period, 24 mg daily xanthohumol was safe and well-tolerated by healthy adults.

Langley, Blake↗
DOE OSTI2022

Bioenergy Underground: Challenges and opportunities for phenotyping roots and the microbiome for sustainable bioenergy crop production

Abstract Bioenergy production often focuses on the aboveground feedstock production for conversion to fuel and other materials. However, the belowground component is crucial for soil carbon sequestration, greenhouse gas fluxes, and ecosystem function. Roots maximize feedstock production on marginal lands by acquiring soil resources and mediating soil ecosystem processes through interactions with the microbial community. This belowground world is challenging to observe and quantify; however, there are unprecedented opportunities using current methodologies to bring roots, microbes, and soil into focus. These opportunities allow not only breeding for increased feedstock production but breeding for increased soil health and carbon sequestration as well. A recent workshop hosted by the USDOE Bioenergy Research Centers highlighted these challenges and opportunities while creating a roadmap for increased collaboration and data interoperability through standardization of methodologies and data using F.A.I.R. principles. This article provides a background on the need for belowground research in bioenergy cropping systems, a primer on root system properties of major U.S. bioenergy crops, and an overview of the roles of root chemistry, exudation, and microbial interactions on sustainability. Crucially, we outline how to adopt standardized measures and databases to meet the most pressing methodological needs to accelerate root, soil, and microbial research to meet the pressing societal challenges of the century.

09 BIOMASS FUELS↗
DOE OSTI2019

Ecological Processes Shaping Bulk Soil and Rhizosphere Microbiome Assembly in a Long-Term Amazon Forest-to-Agriculture Conversion

Forest-to-agriculture conversion has been identified as a major threat to soil biodiversity and soil processes resilience, although the consequences of long-term land use change to microbial community assembly and ecological processes have been often neglected. In this paper, we combined metagenomic approach with a large environmental dataset, to (i) identify the microbial assembly patterns and, (ii) to evaluate the ecological processes governing microbial assembly, in bulk soil and soybean rhizosphere, along a long-term forest-to-agriculture conversion chronosequence, in Eastern Amazon. We hypothesized that (i) microbial communities in bulk soil and rhizosphere have different assembly patterns and (ii) the weight of the four ecological processes governing assembly differs between bulk soil and rhizosphere and along the chronosequence in the same fraction. Community assembly in bulk soil fitted most the zero-sum multinomial (ZSM) neutral-based model, regardless of time. Low to intermediate dispersal was observed. Decreasing influence of abiotic factors was counterbalanced by increasing influence of biotic factors, as the chronosequence advanced. Undominated ecological processes of dispersal limitation and variable selection governing community assembly were observed in this soil fraction. For soybean rhizosphere, community assembly fitted most the lognormal niche-based model in all chronosequence areas. High dispersal and an increasing influence of abiotic factors coupled with a decreasing influence of biotic factors were found along the chronosequence. Thus, we found a dominant role of dispersal process governing microbial assembly with a secondary effect of homogeneous selection process, mainly driven by decreasing aluminum and increased cations saturation in soil solution, due to long-term no-till cropping. Together, our results indicate that long-term no-till lead community abundances in bulk soil to be in a transient and conditional state, while for soybean rhizosphere, community abundances reach a periodic and permanent distribution state. Dominant dispersal process in rhizosphere, coupled with homogeneous selection, brings evidences that soybean root system selects microbial taxa via trade-offs in order to keep functional resilience of soil processes.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

Understanding the Lung Abscess Microbiome: Outcomes of Percutaneous Lung Parenchymal Abscess Drainage with Microbiologic Correlation

IntroductionLung parenchymal abscesses represent an uncommon pathology with high mortality if untreated. Although most respond well to antibiotics, the optimal therapy for persistent abscesses is unknown. The purpose of this study was to review the outcomes of percutaneous lung parenchymal abscess catheter drainage after broad-spectrum antibiotic therapy failure and correlate with patient microbiologic samples.Materials and MethodsRetrospective review of patients who underwent percutaneous lung abscess drainage at a tertiary hospital system from 2005 to 2015 was performed. In total, 19 procedures were identified on 16 different patients; six females and ten males. Mean patient age was 55 years (range 22–81). Median follow-up time was 7 months (range <1–78).ResultsTechnical success was 100%. There was one major complication, a pneumothorax. Follow-up was until tube removal or death in 100% of patients. Catheters were removed with resolution of the abscess cavity in 58% (11/19) or with non-draining abscess cavities in 21% (4/19) for a clinical success rate of 79%. Blood cultures demonstrated no growth in all cases, while 21% (4/19) of sputum or bronchoscopic cultures demonstrated growth. In comparison, the specimens from initial catheter placement isolated a causative organism in 95% (18/19) of case (p < 0.0001).ConclusionIn cases of persistent lung abscess after broad-spectrum antibiotics, percutaneous abscess drainage is highly sensitive for microbiologic sampling compared to sputum/bronchoscopic or blood cultures. Additionally, percutaneous drainage of lung parenchymal abscess cavities may promote resolution of the abscess with high rates of therapeutic success and low complications.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2020

Reducing host DNA contamination in 16S rRNA gene surveys of anthozoan microbiomes using PNA clamps

Efforts to study the microbial communities associated with corals can be limited by inefficiencies in the sequencing process due to high levels of host amplification by universal bacterial 16S rRNA gene primers. Here, we develop an inexpensive peptide nucleic acid (PNA) clamp that binds to a target sequence of host DNA during PCR and blocks amplification. We then test the ability of this PNA clamp to mitigate host contamination and increase overall microbial sequence coverage on samples from three coral species: the gorgonians Eunicea flexuosa and Gorgonia ventalina, and the scleractinian Porites panamensis. The 20-bp PNA clamp was designed using DNA from E. flexuosa. Adding the PNA clamp during PCR increased the percentage of microbial reads in E. flexuosa samples more than 11-fold. Microbial community diversity was similar without- and with-PNA clamps, as were the relative frequencies of the ten most abundant ASVs (amplicon sequence variants), indicating that the clamps successfully blocked host DNA amplification while simultaneously increasing microbial DNA amplification proportionally across the most abundant taxa. The reduction of E. flexuosa DNA correlated with an increase in the abundance of rarer taxa. The clamp also increased the average percentage of microbial reads in another gorgonian, G. ventalina, by 8.6-fold without altering the microbial community beta diversity, and in a distantly related scleractinian coral, P. panamensis, by nearly double. The reduction of host contamination correlated with the number of nucleotide mismatches between the host amplicon and the PNA clamp. The PNA clamp costs as little as $0.48 per sample, making it an efficient and cost-effective solution to increase microbial sequence coverage for high-throughput sequencing of coral microbial communities.

16S rRNA gene sequencing↗