Engineering topics

Galindo, C., Jr.

Publications and source records attributed to Galindo, C., Jr..

6 records

NASA NTRS2010

Biogeochemical Activity of Siderophilic Cyanobacteria and Insights from their Genomes Implications for the Development of New Biosignatures

Verifying the links between genomie features in living organisms and their mineralization/demineralization activity will help to reveal traces of life on Earth and beyond. Among contemporary environments, iron-depositing hot springs (IDHS) may represent one of the most appropriate natural models for insights into ancient life since organisms may have originated on Earth and possibly Mars in association with hydrothennal activity and high [Fe(2+)]. Siderophilic or "iron-loving" cyanobacteria (CB) inhabiting IDHS may have genomic features and properties similar to those of ancient organisms because abundant Fe(2+) in IDHS has a strong potential to increase the magnitude of oxidative stress. That is why specific and/or additional proteins involved in Fe mineralization by siderophilic CB are expected. Inorganic polyphosphates (PPi) are known to increase the viability of prokaryotes Linder heavy metal concentrations and UV stress conditions. PPi have also been proposed as biosignatures. Ancient CB could have also been stressed by occasional migrations from the Fe(2+) rich Ocean to the basaltic land which was almost devoid of dissolved Fe(2+). Thus, the study of the adaptation reactions of siderophilic CB to fluctuation of dissolved Fe level may shed light on the paleophysiology of ancient oxygenic prokaryotes. Moreover, bioweathered Fe, Al, P, Cu, Ti and rare earth elements can be thought of as candidate organomarkers that document the effects of or ganic molecules in weathered rocks. However, the molecular mechanisms of the maintenance of Fe homeostasis in siderophilic CB, the role of PPi for this process and bioweathering activities are poorly understood. Here we present preliminary results describing a new mechanism of Fe mineralization in siderophilic CB, the effect of Fe on the generation of PPi bodies in siderophilic CB, their bioweathering activity and preliminary analysis of the diversity of proteins involved in the prevention of oxidative stress in phototrophs inhabiting IDHS.

Brown, I. I.↗

NASA NTRS2009

Integrated Bio-ISRU and Life Support Systems at the Lunar Outpost: Concept and Preliminary Results

We continue the development of our concept of a biotechnological loop for in-situ resource extraction along with propellant and food production at a future lunar outpost, based on the cultivation of litholytic cyanobacteria (LCB) with lunar regolith (LR) in a geobioreactor energized by sunlight. Our preliminary studies have shown that phototropic cultivation of LCB with simulants of LR in a low-mineralized medium supplemented with CO2 leads to rock dissolution (bioweathering) with the resulting accumulation of Fe, Mg and Al in cyanobacterial cells and in the medium. LCB cultivated with LR simulants produces more O2 than the same organisms cultivated in a high-mineralized medium. The loss of rock mass after bioweathering with LCB suggests the release of O from regolith. Further studies of chemical pathways of released O are required. The bioweathering process is limited by the availability of CO2, N, and P. Since lunar regolith is mainly composed of O, Si, Ca, Al and Mg, we propose to use organic waste to supply a geobioreactor with C, N and P. The recycling of organic waste, including urine, through a geobioreactor will allow for efficient element extraction as well as oxygen and biomass production. The most critical conclusion is that a biological life support system tied to a geobioreactor might be more efficient for supporting an extraterrestrial outpost than a closed environmental system.

Brown, I. I.↗

NASA NTRS2007

Plant Productivity and Characterization of Zeoponic Substrates after Three Successive Crops of Radish (Raphanus sativus L.)

The National Aeronautics and Space Administration (NASA) has developed a zeolite-based synthetic substrate, termed zeoponics. The zeoponic substrate (consisting of NH4(-) and K-exchanged clinoptilolite, synthetic apatite, and dolomite) provides all of the plant-essential nutrients through mineral dissolution and ion exchange, with only the addition of water. Previous studies have shown high productivity of wheat in zeoponic substrates; however, no experiments have been conducted on other crops. The objective of this study was to determine the productivity and nutrient uptake of radish (Raphanus sativus L.) grown in zeoponic substrates with three successive crops in the same substrate. Radish was chosen because of its sensitivities to NH4(+). Average fresh weights of edible roots were similar for radish grown in zeoponic substrates watered with deionized H2O (10.97 g/plant) and in potting mix control substrate irrigated with nutrient solution (10.92 g/plant). Average fresh weight production of edible roots for radish grown in same zeoponic substrate increased in yield over time with the lowest yield in the first crop (7.10 g/plant) and highest in the third crop (13.90 g/plant). The Ca plant tissue levels in radishes (1.8-2.9 wt. %) grown in zeoponic substrates are lower than the suggested sufficient range of 3.0-4.5 wt. % Ca; however, the Ca level is highest (2.9 wt. %) in radishes grown in the third crop in the same zeoponic substrates. The higher radish yield in the third crop was attributed to a reduction in an NH4(-) induced Ca deficiency that has been previously described for wheat grown in zeoponic substrates. The P levels in plant tissues of radish grown in the zeoponic substrates ranged from 0.94-1.15 wt. %; which is slightly higher than the sufficient levels of 0.3-0.7 wt. %. With the exception of Ca and P, other macronutrient and micronutrient levels in radish grown in zeoponic substrates were well within the recommended sufficient ranges. After three successive crops of radish growth, the zeoponic substrates had 52% of the original NH4(-)N and 78% of the original K remaining on zeolite exchange sites. Zeoponic substrates are capable of long-term productivity of radishes for space.

Gruener, J. E.↗

NASA NTRS2006

Plant productivity and characterization of zeoponic substrates after three successive crops of radish

The National Aeronautics and Space Administration (NASA) has developed advanced life support (ALS) systems for long duration space missions that incorporate plants to regenerate the atmosphere (CO2 to O2), recycle water (via evapotranspiration), and produce food. NASA has also developed a zeolite-based synthetic substrate consisting of clinoptilolite and synthetic apatite to support plant growth for ALS systems (Ming et al., 1995). The substrate is called zeoponics and has been designed to slowly release all plant essential elements into "soil" solution. The substrate consists of K- and NH4-exchanged clinoptilolite and a synthetic hydroxyapatite that has Mg, S, and the plant-essential micronutrients incorporated into its structure in addition to Ca and P. Plant performance in zeoponic substrates has been improved by the addition of dolomite pH buffers, nitrifying bacteria, and other calcium-bearing minerals (Henderson et al., 2000; Gruener et al., 2003). Wheat was used as the test crop for all of these studies. The objectives of this study were to expand upon the previous studies to determine the growth and nutrient uptake of radish in zeoponic substrates and to determine the nutrient availability of the zeoponic substrate after three successive radish crops.

Gruener, J. E.↗

NASA NTRS2003

Common Ion Effects In Zeoponic Substrates: Dissolution And Cation Exchange Variations Due to Additions of Calcite, Dolomite and Wollastonite

c1inoptilolite-rich tuff-hydroxyapatite mixture (zeoponic substrate) has the potential to serve as a synthetic soil-additive for plant growth. Essential plant macro-nutrients such as calcium, phosphorous, magnesium, ammonium and potassium are released into solution via dissolution of the hydroxyapatite and cation exchange on zeolite charged sites. Plant growth experiments resulting in low yield for wheat have been attributed to a Ca deficiency caused by a high degree of cation exchange by the zeolite. Batch-equilibration experiments were performed in order to determine if the Ca deficiency can be remedied by the addition of a second Ca-bearing, soluble, mineral such as calcite, dolomite or wollastonite. Variations in the amount of calcite, dolomite or wollastonite resulted in systematic changes in the concentrations of Ca and P. The addition of calcite, dolomite or wollastonite to the zeoponic substrate resulted in an exponential decrease in the phosphorous concentration in solution. The exponential rate of decay was greatest for calcite (5.60 wt. % -I), intermediate for wollastonite (2.85 wt.% -I) and least for dolomite (1.58 wt.% -I). Additions of the three minerals resulted in linear increases in the calcium concentration in solution. The rate of increase was greatest for calcite (3.64), intermediate for wollastonite (2.41) and least for dolomite (0.61). The observed changes in P and Ca concentration are consistent with the solubilities of calcite, dolomite and wollastonite and with changes expected from a common ion effect with Ca. Keywords: zeolite, zeoponics, common-ion effect, clinoptilolite, hydroxyapatite

Beiersdorfer, R. E.↗

NASA NTRS1985

Guide to using lunar soil and simulants for experimentation

It is pointed out that lunar soil can be described as well-graded silty sands or sandy silts with an average particle size by weight in the range from 0.040 to 0.130 mm. The density of in situ bulk lunar soil is typically 1.4 to 1.9 g/cu cm. Changes in soil from moon to laboratory are considered along with some critical differences between simulants and lunar soil. Attention is given to agglutinates, iron metal distributed throughout the agglutinatic glass, solar wind hydrogen, and major lunar minerals (anorthite, pyroxene, ilmenite, olivine). The use of lunar fines as experimental samples is discussed, and the characteristics of simulants for experiments are examined, taking into account grain size distribution, particle type distribution, a highlands simulant, and a high titanium mare simulant. Simulants for testing equipment and structures are also described.

Allton, J. H.↗