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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.

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At least 163 records · Page 9

Culture systems and methods of using same

Culture systems and methods of using same. The systems include a housing defining an inner space. The inner space includes a headspace and at least a portion of a reservoir. A surface for immobilizing cells is moveable between the headspace and the reservoir. The systems can be used for coculturing methanotrophs and phototrophs for processing biogas and wastewater, particularly from anaerobic digesters.

He, Qinghua↗

Metabolic Fluxes of Nitrogen and Pyrophosphate in Chemostat Cultures of Clostridium thermocellum and Thermoanaerobacterium saccharolyticum

This study discusses the fate of pyrophosphate in the metabolism of two thermophilic anaerobes that lack a soluble irreversible pyrophosphatase as present in Escherichia coli but instead use a reversible membrane-bound proton-pumping enzyme. In such organisms, the charging of tRNA with amino acids may become more reversible. This may contribute to the observed excretion of amino acids during sugar fermentation by Clostridium thermocellum and Thermoanaerobacterium saccharolyticum . Calculation of the energetic advantage of reversible pyrophosphate-dependent glycolysis, as occurs in Clostridium thermocellum , could not be properly evaluated, as currently available genome-scale models neglect the anabolic generation of pyrophosphate in, for example, polymerization of amino acids to protein. This anabolic pyrophosphate replaces ATP and thus saves energy. Its amount is, however, too small to cover the pyrophosphate requirement of sugar catabolism in glycolysis. Consequently, pyrophosphate for catabolism is generated according to ATP + P i → ADP + PP i .

59 BASIC BIOLOGICAL SCIENCES↗

Diagnosing and Predicting Mixed-Culture Fermentations with Unicellular and Guild-Based Metabolic Models

Microbiomes are vital to human health, agriculture, and protecting the environment. Predicting behavior of self-assembled or synthetic microbiomes, however, remains a challenge. In this work, we used unicellular and guild-based metabolic models to investigate production of medium-chain fatty acids by a mixed microbial community that is fed multiple organic substrates. Modeling results provided insights into metabolic pathways of three medium-chain fatty acid-producing guilds and identified potential strategies to increase production of medium-chain fatty acids. This work demonstrates the role of metabolic models in augmenting multi-omic studies to gain greater insights into microbiome behavior.

59 BASIC BIOLOGICAL SCIENCES↗

Materials and Fuels Complex Human Performance and Nuclear Safety Culture Pocket Guide

The facilities at the Materials and Fuels Complex (MFC) contain a diverse collection of nuclear research and development capabilities which enable experiments and engineering to drive the world’s nuclear energy future. It is our responsibility to ensure safe, efficient, and reliable operation of MFC facilities to support INL’s nuclear science and technology and national security missions. The MFC management plan makes it clear that safely achieving this takes the right people using good processes.

99 GENERAL AND MISCELLANEOUS↗

Determination of Total, Organic, and Inorganic Carbon and Total Nitrogen in Biological Cultures and Liquid Fraction Process Samples: Laboratory Analytical Procedure (LAP)

This Laboratory Analytical Procedure (LAP) describes the quantitative determination of total organic carbon, inorganic carbon in whole suspended biological samples and in the cell-free supernatant, by combustion and CO 2 detection with a non-dispersive infrared (NDIR) detector. This allows for distinct reporting of soluble and insoluble organic and inorganic carbon. In addition, this procedure covers the quantitative determination of soluble nitrogen in the cell-free supernatant.

09 BIOMASS FUELS↗

Imaginary admittance and charge transfer resistance correlate to the physiological status of Shewanella oneidensis cultures in real time

Monitoring microbial activity is essential for industrial and environmental applications to proceed efficiently. To minimize time and labor-intensive monitoring, a new paradigm is required for in-situ, real time analysis. Since bioconversion of organics is accomplished by microorganisms through the oxidation of feedstocks linked to the reduction of electron acceptors, microorganisms can be viewed as electrochemical catalysts. In this respect, cell membranes have an electrical potential, which is analogous to a conventional capacitor and linked dynamically to cellular activity. Here, in this study, we demonstrate the use of electrochemical impedance spectrometry (EIS) and cyclic voltammetry (CV) for monitoring microbial metabolic activity in real time, in-situ. The effect of organic electron donors as a function of concentration to the physiological status of strains of Shewanella oneidensis was determined. In this study, the pyomelanin overproducer (S. oneidensis ΔhmgA) and the pyomelanin deficient mutant (S. oneidensis ΔmelA) were chosen due to different surface electrochemical characteristics along with differences in oxygen utilization efficiency. CV, relative admittance, phase shift and permittivity changed with growth status and correlated with electron flow from organic carbon sources and terminal electron acceptor availability. This work offers a novel and inexpensive approach to real time monitoring with the advantage of abundant data.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

The impacts of building characteristics, social psychological and cultural factors on indoor environment quality productivity belief

Indoor environmental quality (IEQ) plays a key role in determining occupants' productivity at work; however, analyses of the interconnected factors among building physical, attitudinal, social and demographic components in one study are lacking. To fill this research gap, this study investigates these interconnected factors' influence on occupants’ IEQ-productivity belief, defined as a personal, subjective evaluation of the linkage between the impacts of five IEQ aspects (the quality of indoor temperature, air, natural and electric lighting, and acoustics) and productivity. A cross-sectional survey data was collected in university offices from six countries (Brazil, Italy, Poland, Switzerland, Taiwan and the U.S.). Results of multiple linear regression models indicate that IEQ satisfaction is the strongest positive predictor of the IEQ-productivity belief and this relationship is stronger in private offices. Country of residence is the second primary predictor. Several attitudinal-behavioral factors, including thermal comfort, perceived ease of controlling indoor environmental features, and attitudes toward sharing controls are all positively associated with IEQ-productivity belief. Interestingly, the level of control accessibility to light switches has the strongest impact as opposed to other controls. On the other hand, group norms and conformity intention are not significant predictors. Regarding demographics, men are more likely than women to perceive the IEQs to have positive impacts on their productivity, without considering other variables in the regression model; however, women are more likely than men to consider all IEQs as having positive impacts on productivity, after considering other variables. Furthermore, our findings provide suggestions for prioritizing wellness in the workplace since the early design stage.

99 GENERAL AND MISCELLANEOUS↗

Most of the rhamnogalacturonan-I from cultured Arabidopsis cell walls is covalently linked to arabinogalactan-protein

To characterize a purified rhamnogalacturonan-I (RG-I) containing both RG-I and arabinogalactan-protein (AGP) types of glycosyl residues, an AGP-specific β-1,3-galactanase that can cleave the AG backbone and release the AG sidechain was applied to this material. Carbohydrate analysis and NMR spectroscopy verified that the galactanase-released carbohydrate consists of RG-I covalently attached to the AG sidechain, proving a covalent linkage between RG-I and AGP. Size exclusion chromatography-multiangle light scattering-refractive index detection revealed that the galactanase-released RG-I has an average molecular weight of 41.6 kDa, which, together with the percentage of pectic sugars suggests an RG-I-AGP comprising one AGP covalently linked to two RG-I glycans. Carbohydrate analysis and NMR results of the RG-I-AGP, the galactanase-released glycans, and the RG lyase-released glycans demonstrated that the attached RG-I glycans are decorated with α-1,5-arabinan, β-1,4-galactan, xylose, and 4-O-Me-xylose sidechains. Furthermore, our measurement suggests that the covalently linked RG-I-AGP is the major component of the traditionally prepared RG-I.

59 BASIC BIOLOGICAL SCIENCES↗