Merged

National Aeronautics and Space Administration
Synthetic Biological Membranes (SBM)
Abdelrahman Budair 1 , Michael Flynn 2 , Jaione Romero-Mangado 2 , Jurek Parodi 2
1
University of Cambridge, 2 NASA Ames Research Center
Abstract
One of the problems faced by long human space flight missions is the reliability of the advanced life support systems. It affects both the safety and the cost of the mission. This project tests and develops a novel membrane that uses a biomimetic
technology to generate the Synthetic Biological Membrane (SBM). This membrane increases the reliability of the system by mimicking biological membranes found in the cells of the human body. A lipid-based membrane was developed to purify
wastewater that has the ability to self-repair when exposed to physical or chemical damage. The SBM uses forward osmosis to purify water that includes genetically modified organisms that are grown in the osmotic agent secreting fatty acids that
diffuse across the membrane to the feed, providing a sacrificial protective layer on the active side of the membrane. Different membranes are being tested in the lab by first trying to foul the membrane using calcium carbonate and then by trying to
defoul it with the genetically modified cyanobacteria providing the needed fatty acids as a sacrificial layer. Other experiments are conducted to test the permeability of the membranes for certain desirable fatty acids and their role in protecting the
membrane from any mineral scale, organic fouling, and oxidative damage. This technology is suitable to be used in human missions to Mars that lasts two or three years without the need to repair the membranes in addition to its capability of
revolutionizing water treatment on Earth.
Experimental Methodology
Feed O.A. Day #3 O.A. Day #3 O.A. Day #8
T.O.C (wt%) 20.7 4.6 4.9 6.7
FeedLoop
Pressure
Transducer
OALoop
Pressure
Transducer
Total organic carbon (T.O.C) results show transfer of the palmitic acid from the feed side to the
osmotic agent (O.A.) side that proves the permeation of the fatty acids across the membrane.
FeedTank
FeedLoop
FeedLoop
FlowMeter
FeedPump
FeedScale
MembraneContactors
Pressure
Differen al
Transmi er
OALoop
OALoop
FlowMeter
OAPump
OAScale
OATank
• Genetically engineered strains of Synechococcus sp. PCC
7002 (SO7) produces palmitic acid, myristic acid and stearic
acid (red arrows) in concentrations reaching >130 mg/L.
• These fatty acids will provide a sacrificial layer for the
synthetic biological membrane.
• SO7 were grown in A+
supplemented
with
spectinomycin sulfate at 26
°C, 150rpm,60 umol/m 2 s in a
16 h light and 8 h dark cycle.
• Each column of the 96 well
plate contains A+ and a
different salt concentration
(NaCl) to determine the salt
tolerance of SO7 for future
growth in the OA.
• The above diagram represents the system used to test
the biomimetic membrane. An efficient water treatment
system for human space missions to purify urine,
hygiene water and humidity condensate into potable
water.
• Forward osmosis process is used to purify the solution
with a driving force created by the osmotic pressure
difference. Water crosses the membrane to the osmotic
agent side that has higher osmotic pressure, separating
it from its contaminants.
• Two experiments were conducted
1. Fouling of the membrane:
Calcium carbonate was used in the feed side and a
NaCl solution as the osmotic agent to create the
osmotic potential difference. Decrease in
efficiency of the membrane was noticed as the
flow rate decreases with each further run. A study
conducted on the effect of number of hour runs on
the efficiency of the membrane. Fatty acids
produced by genetically modified cyanobacteria
will be used to mitigate membrane fouling.
2. Permeation for fatty acids across the membrane:
Palmitic acid was used as a representative of the
three fatty acids secreted by the genetically
modified cyanobactetria. A study for the
permeation of palmitic acid across the membrane
was conducted by measuring the total organic
carbon (T.O.C) on the osmotic agent side. The
fatty acids will work as a sacrificial layer (crossing
the membrane to the active side of it) removing
any fouling materials. Raman Spectroscopy was
Volume [ml]
Results
Raman Spectroscopy spectra of the control FO membrane (red) and the FO membrane used
for FA permeation studies (blue). The data was collected using a 785 nm laser and the samples
were focused through a 50x objective of the microscope. The spectrometer was operated in the
extended mode at 500 mW laser power. The signal was recorded from 365 to 3200 cm- 1 and
the acquisition time for all spectra was 60 s.
Osmotic Agent
900
• The diagram shows a decrease
850 in the flow rate of the system in
the last run that lasted 8 days.
800
• Calcium carbonate is found to
750 be one of the factors for
membranes to foul.
Conclusion and Future Work
700
Contact Information
650
O.A. #1 O.A. #2
O.A. #3 O.A. #4
600
O.A. #5 O.A. #6
Abdelrahman Budair:
Michael Flynn:
550
O.A. #7
www.nasa.gov
• a.a.budair@gmail.com
• michael.flynn@nasa.gov
“Confidential used to identify the layer formed - by Not the fatty acid. for distribution - pre-production
500
Jaione Romero-Mangado:
Jurek Parodi:
copy “
12:00:00 AM 1:12:00 AM 2:24:00 AM 3:36:00 AM 4:48:00 AM 6:00:00 AM 7:12:00 AM 8:24:00 AM
Time
The diagram shows the growth rate of SO7 as a function of salinity (2.5%-9% NaCl) during 14 days.
Optical density (OD) readings were taken every 24 hours until no additional growth was detected.
The membrane efficiency decreased over time when using Calcium Carbonate in the feed
solution. Palmitic acid was found to pass across the membrane and precipitated on the membrane
creatin a sacrificial layer. The genetically modified Synechococcus sp. produced palmitic acid,
myristic acid and stearic acid and it grows in salt concentrations between 2.5-9%. The next step is
to integrate all the work in one system and test its reliability for water purification and its ability to
repair itself without the need of human intervention.
References
• Ruffing, A. M. (2014). Improved free fatty acid production in cyanobacteria with Synechococcus
sp. PCC 7002 as host. Frontiers in bioengineering and biotechnology, 2.
• Flynn, M., Romero, J., Parodi, J., Mancenelli, R., Dougherty, M., & Loftus, D. (2016, July).
Synthetic Biological Membrane. 46th International Conference on Environmental Systems.
Acknowledgments
Special thanks to the Crown Prince Foundation (CPF) for funding this internship program from
Jordan. Also to NASA Ames Research Center and NASA International Internships Program I^2 for
their great support offering this unique opportunity to conduct this research under their supervision.
• jaione.romeromangado@nasa.gov
• jurek.parodi@nasa.gov
i rischi sono calcolati, ma allora, con gli strumenti
dell’epoca, l’idea di attraversare l’Atlantico fu qualcosa
di veramente coraggioso”.
LIBERTA’ E DINAMISMO
In America da cinque anni, Jurek Parodi si sente un
cittadino del mondo. “Dell’Italia apprezzo la cultura,
l’educazione che mi ha dato, e soprattutto il senso di
appartenenza, l’identità se vogliamo – sottolinea - ma
anche qui in America, e forse in California specialmente,
ci sono cose da amare, come il fatto di unire
tanti mondi diversi senza appartenere a nessuno”.
Libertà e dinamismo, quindi, che Parodi ritrova ogni
giorno aprendo le porte dei laboratori della NASA.
“Non c’è nulla che non ami della mia vita all’agenzia,
– racconta – la mia è stata una questione di fortuna,
certo, ma anche di merito, perché ho lavorato tanto
per arrivare dove sono”. Nel suo futuro c’è e continuerà
ad esserci, la scienza anche se come questa
continuerà a svilupparsi, in che modi e soprattutto in
quali settori, dipenderà probabilmente da altri fattori.
“Sembra che la nostra società viva sull’orlo di una
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autem sam autam adipiciendi dolore eumquatur,
abor aliquas apis eictur auta por ma di cus aspitin
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nem alit, cullanto con nihilig enihicipsam id molesse
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et veliquo dio officipsum id mod quiaspiet harupta
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