Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “lactic”

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 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

In-Situ Surface Construction of Infrastructure

In situ resources offer an opportunity to reduce the amount of items brought from Earth when exploring moons and planets. Utilizing those resources requires energy that comes with a cost. In the case of human missions to Mars, trading surface power for launch mass is beneficial for propellant and consumables required to sustain human pioneering and settlement on the planet’s surface. However, In Situ Resource Utilization (ISRU) can mean far more than propellant production and consumables replacement for missions beyond Low Earth Orbit. NASA’s Systems Capability Leader-ship Team (SCLT) for ISRU created a work break-down structure based on functions identified in roadmaps pertaining to human exploration. That WBS includes Prospecting, Extraction, Processing, Construction, Manufacturing, and Energy. Over the years, NASA has developed some capabilities and technologies for prospecting, extraction, and processing carbon dioxide and water on Mars into propellants and life support consumables. However, that is a small subset of the ISRU needs that are coming to light with NASA’s push to return to the Moon for extended periods of time. For instance, astronauts require shielding from Ga-lactic Cosmic Rays and nuclear radiation and protection from the low temperatures and pressures in Space. Surface assets including crew, landers, and ascent modules can be damaged by surface ejecta during landing and launch operations on the Moon and Mars. Creating shielding, berms, and pads requires movement of large volumes and stabilization of regolith in the context of a civil engineering construction project. Because of the multi-disciplinary nature of the aerospace systems needed for human exploration, SCLT on ISRU created an ISRU Construction Integrated Steering Group that combines expertise among several NASA Principal Technologists and Capabilities Leaders for exploring options, assessing opportunities, and developing requirements for construction and manufacturing on the Moon and Mars NASA’s new program to develop Lunar landers for small, mid, and large payload deliveries to the Lunar surface leading to human missions by 2025 spawned an investigation into plume surface interactions caused by the lander during descent and ascent. The trade space to resolve this issue includes regolith stabilization via landing pad construction techniques and lander nozzles characteristics due to vehicle systems design. Some data exists from the Apollo missions but more is required for the missions ahead. The purpose of this paper [1] is to outline an approach for developing requirements that can guide systems designs while taking advantage of flight opportunities in NASA’s plans to return to the Moon.

In-Situ↗
NASA NTRSDate not supplied

Strategies for Determining Safety of Fermented Foods Produced in Space

The BioNutrients experiments examine the feasibility of using microbially produced foods – yogurt, kefir, fermented food products– to supplement the current prepackaged food system to provide freshly synthesized nutrients and genetically engineered protein therapeutics to support crew health for sustainable and long duration crewed exploration. Safety of the products must be established as direct consumption of such products is a risk due to potential contamination with pathogenic organisms. Identifying pathogen contamination is particularly challenging as the fermenting cultures can mask the presence of contaminating organisms. Here we consider current methods of detecting coliforms, aerobic colonies, non-lactic acid bacteria, molds (yeasts), and specific pathogens including Staphylococcus aureus and salmonella. We also consider alternate and additional testing including sequencing and quantitative PCR. We investigate the use of the E-Nose developed by NASA Ames Research Center. This portable device senses volatile organic compounds in real time and can be trained to recognize “good” uncontaminated products from contaminated ones as a means of predicting food safety. Finally, we consider methods of in-flight pasteurization to increase safety and decrease overall microbial load of these products. This presentation will summarize testing status and outline the strategy that will be employed in the BioNutrients-3 ISS fermented foods experiment.

Natalie Ball↗
NASA NTRSDate not supplied

Strategies for Determining Safety of Fermented Foods Produced in Space

The BioNutrients experiments examine the feasibility of using microbially produced foods – yogurt, kefir, fermented food products– to supplement the current prepackaged food system to provide freshly synthesized nutrients and genetically engineered protein therapeutics to support crew health for sustainable and long duration crewed exploration. Safety of the products must be established as direct consumption of such products is a risk due to potential contamination with pathogenic organisms. Identifying pathogen contamination is particularly challenging as the fermenting cultures can mask the presence of contaminating organisms. Here we consider current methods of detecting coliforms, aerobic colonies, non-lactic acid bacteria, molds (yeasts), and specific pathogens including Staphylococcus aureus and salmonella. We also consider alternate and additional testing including sequencing and quantitative PCR. We investigate the use of the E-Nose developed by NASA Ames Research Center. This portable device senses volatile organic compounds in real time and can be trained to recognize “good” uncontaminated products from contaminated ones as a means of predicting food safety. Finally, we consider methods of in-flight pasteurization to increase safety and decrease overall microbial load of these products. This presentation will summarize testing status and outline the strategy that will be employed in the BioNutrients-3 ISS fermented foods experiment.

Food↗
NASA NTRS2024

Primordial Aqueous Alteration Recorded in Water-Soluble Organic Molecules from the Carbonaceous Asteroid (162173) Ryugu

We report primordial aqueous alteration signatures in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu by the Hayabusa2 spacecraft of JAXA. Newly identified low-molecular-weight hydroxy acids (HO-R-COOH) and dicarboxylic acids (HOOC-R-COOH), such as glycolic acid, lactic acid, glyceric acid, oxalic acid, and succinic acid, are predominant in samples from the two touchdown locations at Ryugu. The quantitative and qualitative profiles for the hydrophilic molecules between the two sampling locations shows similar trends within the order of ppb (parts per billion) to ppm (parts per million). A wide variety of structural isomers, including α- and β-hydroxy acids, are observed among the hydrophilic molecules. We also identify pyruvic acid and dihydroxy and tricarboxylic acids, which are biochemically important intermediates relevant to molecular evolution, such as the primordial TCA (tricarboxylic acid) cycle. Here, we find evidence that the asteroid Ryugu samples underwent substantial aqueous alteration, as revealed by the presence of malonic acid during keto–enol tautomerism in the dicarboxylic acid profile. The comprehensive data suggest the presence of a series for water-soluble organic molecules in the regolith of Ryugu and evidence of signatures in coevolutionary aqueous alteration between water and organics in this carbonaceous asteroid.

Asteroids, comets and Kuiper belt↗
NASA NTRSDate not supplied

The Future of Astronaut Nutrition: Daily Production of Kefir Nutrient Packs in a Lunar Analog Mission

Astronaut nutrition will need to be supplemented with fresh nutrients and probiotics for long duration space travel. Kefir is a fermented milk beverage that provides probiotic bacteria, protein, calcium, and vitamin K. It has been historically cultured for thousands of years and is a modern-day health food. During the BioNutrients-2 experiment, one generation of kefir was cultured by astronauts on the ISS in fluorinated ethylene propylene (FEP) bags. This follow-on experiment aimed to test the hypothesis that kefir can be produced at ambient temperatures and safely passaged to make a series of nutrient packs in an analog environment. The Hawaiian Space Exploration Analog and Simulation (HI-SEAS) is a semi-controlled habitat located on the Mauna Loa volcano on the island of Hawaii at 2,500 m elevation. The recent EMMIHS (EuroMoonMars, International MoonBase Alliance, HI-SEAS) missions comprised of interdisciplinary, international crews for mock lunar missions. During a six-day mission in March 2024, crew members tested continuous passaging of kefir cultures (C-FIR commercial strain). After approximately 24 hours of growth, a portion of culture was used to seed the next generation of culture bags for four passages. A color board and pH indicator allowed the crew to easily determine when the culture had reached optimal pH. Laboratory analysis at NASA Ames Research Center showed that the pH met Kefir standards (<5). The yeast and lactic acid bacteria were in normal range and no contamination was detected in the final passage. By successfully accomplishing this experiment the team has demonstrated the ability to safely produce daily cultures of kefir in a microgravity applicable growth system.

Astronaut nutrition↗
DOE OSTI2021

Systems and methods for producing nitriles

An aspect of the present disclosure is a method that includes a first reacting a molecule from at least one of a carboxylic acid, an ester of a carboxylic acid, and/or an anhydride with ammonia to form a nitrile, where the first reacting is catalyzed using an acid catalyst. In some embodiments of the present disclosure, the molecule may include at least one of acetic acid, lactic acid, and/or 3-hydroxyproprionic acid (3-HPA). In some embodiments of the present disclosure, the molecule may include at least one of methyl acetate, ethyl lactate, and/or ethyl 3-hydroxypropanoate (ethyl 3-HP). In some embodiments of the present disclosure, the anhydride may be acetic anhydride.

Karp, Eric M.↗
DOE OSTI2022

Muconic Acid Production from P. putida Using High Protein Algae Hydrolysate

The composition of algal biomass is highly dynamic, with protein, lipid, and carbohydrate contents varying in response to nutrient and environmental conditions during cultivation. Because shifts in biomass composition are often associated with reduced biomass productivity, production costs can often increase if targeting higher biomass compositional quality (enriched in carbohydrates or lipids at reduced protein content) as input for the algal biorefinery. The optimal algal biorefinery configuration is thus a function of many factors. One of the key strengths of the Combined Algal Processing (CAP) process is the versatility of feedstocks and products produced. The concept has been demonstrated with ethanol and a variety of carboxylic acids (succinic, butyric, muconic) as coproducts along with lipid upgrading to biofuel. Modification of the approaches, processes and downstream upgrading to fuels has allowed the CAP process to reduce costs and improve efficiency. Muconic acid is a high-value, potential fermentation coproduct of interest because it can be easily converted to adipic acid, a high-volume monomer for the production of nylon and other valuable consumer plastics. As such, the production of muconic acid through CAP was explored to expand the suite of products from algal biomass and to begin exploring the valorization of high protein content biomass from rapidly grown algae biomass. We have established initial performance parameters and shown that the range of substrates consumed by the muconic acid-producing microbe, Pseudomonas putida, includes at least glucose, mannose, glycerol, and lactic acid. We achieved complete utilization of these four major hydrolysate substrates achieving productivities of 0.037 (g/L/h) from Scenedesmus obliquus and 0.029 (g/L/h) from Monoraphidium minutum hydrolysates. Final titer and process yield (mol of muconic acid per mol of substrate (molP/molS)) were 0.99 g/L and 0.42 molP/molS from S. obliquus hydrolysate and 0.75 g/L and 0.23 molP/molS from M. minutum hydrolysate, respectively.

BIOMASS FUELS↗
DOE OSTI2022

pH-sensitive nanoparticles for detecting and preventing food spoilage

Nanoparticles and compositions thereof are provided for detecting and/or preventing food spoilage. Methods of making the nanoparticles and compositions, and methods of using the nanoparticles and compositions, e.g. in food packaging, are also provided. The nanoparticles can have a hydrophobic core containing a hydrophobic active agent, e.g. a hydrophobic dye and/or an antimicrobial agent, for detecting and/or preventing food spoilage. The nanoparticles can also have a copolymer of a hydrophobic polymer repeat unit, e.g. styrene or lactic acid, and a pH responsive dendrimer repeat unit. The pH responsive dendrimer repeat unit can have a pH responsive amine core having a plurality of branched acrylate arms extending therefrom. The nanoparticles can be chemically stable at neutral pH, and then release the hydrophobic active agent at a pH range indicative of food spoilage. By releasing the hydrophobic dye and/or antimicrobial agent, the nanoparticles can detect and/or inhibit food spoilage.

Tong, Zhaohui↗
DOE OSTI2023

Lactiplantibacillus plantarum uses ecologically relevant, exogenous quinones for extracellular electron transfer

Extracellular electron transfer (EET) is a metabolic process that frequently uses quinones to couple intracellular redox reactions with extracellular electron acceptors. The physiological relevance of this metabolism for microorganisms capable of EET but unable to synthesize their own quinones remains to be determined. To address this question, we investigated quinone utilization by Lactiplantibacillus plantarum, a microorganism required for food fermentations, that performs EET and is also a quinone auxotroph. L. plantarum selectively used 1,4-dihydroxy-2-naphthoic acid (DHNA) and more hydrophilic naphthoquinones for EET reduction of insoluble iron (ferrihydrite). However, quinones used for EET also inhibited L. plantarum growth in non-aerated conditions. Transcriptomic analysis showed that DHNA-induced oxidative stress in L. plantarum, but this was alleviated when the electron acceptor, ferric ammonium citrate (FeAC), was included in the growth medium. Although DHNA and FeAC induced L. plantarum EET, this metabolism was still dependent on direct access to environmental electron shuttles. To determine whether quinone-producing food fermentation bacteria could be sources of those electron shuttles, L. plantarum EET was measured after incubation with Lactococcus lactis and Leuconostoc mesenteroides. Quinone-producing L. lactis, but not a quinone-deficient L. lactis ΔmenC mutant, increased L. plantarum ferrihydrite reduction and medium acidification through an EET-dependent mechanism. L. plantarum EET was also stimulated by L. mesenteroides, resulting in greater environmental acidification and transient increases in L. plantarum cell numbers. Our findings show that L. plantarum overcomes the toxic effects of exogenous quinones to use those compounds for EET-conferred, ecological advantages during the early stages of food fermentations.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

MAGs from alcoholic fermentation in sugarcane biorefineries

Genome-resolved metagenomics was applied to recover microbial metagenome-assembled genomes (MAGs) from alcoholic fermentation samples collected at two sugarcane biorefineries in São Paulo state, Brazil, during the 2024 harvest season.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

bioreactor sludge metagenome

Anaerobic fermentation bioreactor microbial communities from Madison, Wisconsin, United States. The goal of this study is to characterize a central set of genes relevant to medium chain fatty acid (MCFA) production to guide screens of putative MCFA-producing microorganisms from additional environments or grown on different substrates.

butyric↗
NASA NTRS2003

Effects of the oral contraceptive pill cycle on physiological responses to hypoxic exercise

To test whether the oral contraceptive pill cycle affects endocrine and metabolic responses to hypoxic (fraction of inspired oxygen = 13%, P(IO2): 95 mmHg; H) versus normoxic (P(IO2):153 mmHg; N) exercise, we examined eight women (28 +/- 1.2 yr) during the third (PILL) and placebo (PLA) weeks of their monthly oral contraceptive pill cycle. Cardiopulmonary, metabolic, and neuroendocrine measurements were taken before, during, and after three 5-min consecutive workloads at 30%, 45%, and 60% of normoxic V(O2peak) in H and N trials. Heart rate response to exercise was greater in H versus N, but was not different between PILL and PLA. Lactate levels were significantly greater during exercise, and both lactate and glucose levels were significantly greater for 30 min after exercise in H versus N (p < 0.0001). When expressed relative to baseline, lactate levels were lower in PILL versus PLA, but glucose was greater in PILL versus PLA (p < 0.001). Cortisol levels were also significantly greater in PILL versus PLA (p < 0.001). Norepinephrine levels were significantly increased during exercise (p < 0.0001) and in H versus N (p < 0.0001). However, epinephrine levels were not different over time or with trial. Thus, the presence of circulating estradiol and progesterone during the PILL phase reduces glucose and lactate responses to hypoxic exercise.

Non-NASA Center↗
NASA NTRS2003

Development of a nanostructured DNA delivery scaffold via electrospinning of PLGA and PLA-PEG block copolymers

The present work utilizes electrospinning to fabricate synthetic polymer/DNA composite scaffolds for therapeutic application in gene delivery for tissue engineering. The scaffolds are non-woven, nano-fibered, membranous structures composed predominantly of poly(lactide-co-glycolide) (PLGA) random copolymer and a poly(D,L-lactide)-poly(ethylene glycol) (PLA-PEG) block copolymer. Release of plasmid DNA from the scaffolds was sustained over a 20-day study period, with maximum release occurring at approximately 2 h. Cumulative release profiles indicated amounts released were approximately 68-80% of the initially loaded DNA. Variations in the PLGA to PLA-PEG block copolymer ratio vastly affected the overall structural morphology, as well as both the rate and efficiency of DNA release. Results indicated that DNA released directly from these electrospun scaffolds was indeed intact, capable of cellular transfection, and successfully encoded the protein beta-galactosidase. When tested under tensile loads, the electrospun polymer/DNA composite scaffolds exhibited tensile moduli of approximately 35 MPa, with approximately 45% strain initially. These values approximate those of skin and cartilage. Taken together, this work represents the first successful demonstration of plasmid DNA incorporation into a polymer scaffold using electrospinning.

Non-NASA Center↗
NASA NTRS2001

Increases in intramuscular pressure raise arterial blood pressure during dynamic exercise

This investigation was designed to determine the role of intramuscular pressure-sensitive mechanoreceptors and chemically sensitive metaboreceptors in affecting the blood pressure response to dynamic exercise in humans. Sixteen subjects performed incremental (20 W/min) cycle exercise to fatigue under four conditions: control, exercise with thigh cuff occlusion of 90 Torr (Cuff occlusion), exercise with lower body positive pressure (LBPP) of 45 Torr, and a combination of thigh cuff occlusion and LBPP (combination). Indexes of central command (heart rate, oxygen uptake, ratings of perceived exertion, and electromyographic activity), cardiac output, stroke volume, and total peripheral resistance were not significantly different between the four conditions. Mechanical stimulation during LBPP and combination conditions resulted in significant elevations in intramuscular pressure and mean arterial pressure from control at rest and throughout the incremental exercise protocol (P < 0.05). Conversely, there existed no significant changes in mean arterial pressure when the metaboreflex was stimulated by cuff occlusion. These findings suggest that under normal conditions the mechanoreflex is tonically active and is the primary mediator of exercise pressor reflex-induced alterations in arterial blood pressure during submaximal dynamic exercise in humans.

Non-NASA Center↗
NASA NTRS2001

Functional and structural adaptations of skeletal muscle to microgravity

Our purpose is to summarize the major effects of space travel on skeletal muscle with particular emphasis on factors that alter function. The primary deleterious changes are muscle atrophy and the associated decline in peak force and power. Studies on both rats and humans demonstrate a rapid loss of cell mass with microgravity. In rats, a reduction in muscle mass of up to 37% was observed within 1 week. For both species, the antigravity soleus muscle showed greater atrophy than the fast-twitch gastrocnemius. However, in the rat, the slow type I fibers atrophied more than the fast type II fibers, while in humans, the fast type II fibers were at least as susceptible to space-induced atrophy as the slow fiber type. Space flight also resulted in a significant decline in peak force. For example, the maximal voluntary contraction of the human plantar flexor muscles declined by 20-48% following 6 months in space, while a 21% decline in the peak force of the soleus type I fibers was observed after a 17-day shuttle flight. The reduced force can be attributed both to muscle atrophy and to a selective loss of contractile protein. The former was the primary cause because, when force was expressed per cross-sectional area (kNm(-2)), the human fast type II and slow type I fibers of the soleus showed no change and a 4% decrease in force, respectively. Microgravity has been shown to increase the shortening velocity of the plantar flexors. This increase can be attributed both to an elevated maximal shortening velocity (V(0)) of the individual slow and fast fibers and to an increased expression of fibers containing fast myosin. Although the cause of the former is unknown, it might result from the selective loss of the thin filament actin and an associated decline in the internal drag during cross-bridge cycling. Despite the increase in fiber V(0), peak power of the slow type I fiber was reduced following space flight. The decreased power was a direct result of the reduced force caused by the fiber atrophy. In addition to fiber atrophy and the loss of force and power, weightlessness reduces the ability of the slow soleus to oxidize fats and increases the utilization of muscle glycogen, at least in rats. This substrate change leads to an increased rate of fatigue. Finally, with return to the 1g environment of earth, rat studies have shown an increased occurrence of eccentric contraction-induced fiber damage. The damage occurs with re-loading and not in-flight, but the etiology has not been established.

Review, Tutorial↗
NASA NTRS1996

The importance of new processing techniques in tissue engineering

The use of polymer scaffolds in tissue engineering is reviewed and processing techniques are examined. The discussion of polymer-scaffold processing explains fiber bonding, solvent casting and particulate leaching, membrane lamination, melt molding, polymer/ceramic fiber composite-foam processing, phase separation, and high-pressure processing.

Non-NASA Center↗