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Team:Tokyo Tech/BlackenedEcoli
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===Increase Reserving thermal energy=== | ===Increase Reserving thermal energy=== | ||
| - | + | E.coli can get thermal energy, even if it is a little, by changing the body-color to black and uses the energy for its metabolism. | |
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===Protection from UV ray=== | ===Protection from UV ray=== | ||
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===Bacterial strains and cultivation=== | ===Bacterial strains and cultivation=== | ||
| - | + | Strain JM109 of Escherichia coli used for melA expressing analysis and was cultured on M9 medium plate supplemented with tyrosine and CuSo4. M9 medium contained, per liter, 200mg Tyrosine, 60mg CuSO4. | |
===Construction of melA expressing vector=== | ===Construction of melA expressing vector=== | ||
Revision as of 17:19, 20 October 2009
| Main | Team | Terraforming | Experiments | [http://partsregistry.org/cgi/partsdb/pgroup.cgi?pgroup=iGEM2009&group=Tokyo_Tech Parts] | Safety |
Contents |
Introduction
One of the famous black pigment is a Melanin which was utilized in a number of organism. Previously. It’s noted that the body color of E.coli was changed from white to black by a large amount of Melanin. Melanin was made by Tyrosinase (EC 1.14.18.1)(melA). Tyrosinase catalyze the first step of Melanin production pathway to make Dopaquinone. After production of Dopaquinone, Melanin is generated by nonenzymatical chain reaction. So, Overexprssion of tyrosinase in E.coli cause a large amount of Melanin. We considered these mechanism enable us to control the Mars temperature, get the heat energy that help to grow bacteria and, protect DNA from UV on the mars surface. Because of Melanin has a high efficiency heat absorption and absorb Ultra Violet.
Purposes
Increase Mars temperature
Increase Reserving thermal energy
E.coli can get thermal energy, even if it is a little, by changing the body-color to black and uses the energy for its metabolism.
Protection from UV ray
UV strength on the Mars’ surface is weakened by initial energy supply. But it can be easily changed by the convection of the atmosphere. So, we think it significant to blacken E.coli, which can protect them from variable UV ray.
How to make darker colored E.coli
Utilize Melanin production pathway
Materials and Methods
Bacterial strains and cultivation
Strain JM109 of Escherichia coli used for melA expressing analysis and was cultured on M9 medium plate supplemented with tyrosine and CuSo4. M9 medium contained, per liter, 200mg Tyrosine, 60mg CuSO4.
Construction of melA expressing vector
melA expressing analysis
We transformed respectively BBa_K193602(placIQ-RBS-melA on pSB4A5) and control(placIQ-RBS on pSB4A5) into JM109 strain, and cultured them. Then we dispersed cultured strains on M9 medium. After 108 hour, we took a picture of these medium and measured darkness of these medium. Darkness was quantified with ImageJ softwere.
Analytical methods
According to Stefan-Boltzmann law, blackbody emit per surface in unit time is calculated as
σT4,
where T is the temperature of the black body and σ = 5.67 * 10 − 8(W / m2K4) is constant value. The total energy that comes from the sun is calculated as
S(1 − A)πr2,
where S = 597(W / m2) is the energy which actually reaches the mars from the sun, A is the albedo of the Mars and r = 3.3972 * 106(m) is the radius of the Mars. Albedo is a ratio at which a planet reflect the sun light. Regarding the Mars as blackbody, the radiative equilibrium temperature of the Mars is estimated as
T=
.
If we succeeded in decreasing the albedo by making the Mars black, the temperature will change as the graph shows. x axis is year and y axis is temperature.
We assume that the albedo decreases as
A = 0.15 * exp( − x).
If we could change the albedo from 0.15 to 0.05, the temperature of the Mars would increase by about 6 Celsius degree.
