Team:Tokyo Tech/BlackenedEcoli

From 2009.igem.org

(Difference between revisions)
Line 13: Line 13:
===Increase Mars temperature===
===Increase Mars temperature===
 +
According to　Stefan-Boltzmann law,
 +
blackbody emit per surface in unit time is calculated as
 +
 +
&sigma;<i>T</i><sup>4</sup>,
 +
 +
where T is the temperature of the black body and &sigma; = 5.67 * 10<sup> &minus; 8</sup>(<i>W</i> / <i>m</i><sup>2</sup><i>K</i><sup>4</sup>) is constant value.
 +
The total energy that comes from the sun is calculated as
 +
 +
<i>S</i>(1 &minus; <i>A</i>)&pi;<i>r</i><sup>2</sup>,
 +
 +
where <i>S</i> = 597(<i>W</i> / <i>m</i><sup>2</sup>) is the energy which actually reaches the mars from the sun,
 +
A is the albedo of the Mars and <i>r</i> = 3.3972 * 10<sup>6</sup>(<i>m</i>) 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=[[Image:Tokyo_Tech_function_T.png|70px]]
 +
<!--<math>T=\sqrt[4]{\frac{S(1-A)}{4\lambda}}</math>-->.
 +
 +
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.
 +
[[Image:Tokyo_Tech_Temperature.gif|200px|thumb|temperature estimation]]
 +
 +
We assume that the albedo decreases as
 +
 +
<i>A</i> = 0.15 * <i>e</i><i>x</i><i>p</i>( &minus; <i>x</i>).
 +
 +
If we could change the albedo from 0.15 to 0.05, the temperature of the Mars would increase by about 6 Celsius degree.
===Increase Reserving thermal energy===
===Increase Reserving thermal energy===
Line 41: Line 69:
===Analytical methods===
===Analytical methods===
-
According to　Stefan-Boltzmann law,
 
-
blackbody emit per surface in unit time is calculated as
 
-
&sigma;<i>T</i><sup>4</sup>,
 
-
 
-
where T is the temperature of the black body and &sigma; = 5.67 * 10<sup> &minus; 8</sup>(<i>W</i> / <i>m</i><sup>2</sup><i>K</i><sup>4</sup>) is constant value.
 
-
The total energy that comes from the sun is calculated as
 
-
 
-
<i>S</i>(1 &minus; <i>A</i>)&pi;<i>r</i><sup>2</sup>,
 
-
 
-
where <i>S</i> = 597(<i>W</i> / <i>m</i><sup>2</sup>) is the energy which actually reaches the mars from the sun,
 
-
A is the albedo of the Mars and <i>r</i> = 3.3972 * 10<sup>6</sup>(<i>m</i>) 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=[[Image:Tokyo_Tech_function_T.png|70px]]
 
-
<!--<math>T=\sqrt[4]{\frac{S(1-A)}{4\lambda}}</math>-->.
 
-
 
-
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.
 
-
[[Image:Tokyo_Tech_Temperature.gif|200px|thumb|temperature estimation]]
 
-
 
-
We assume that the albedo decreases as
 
-
 
-
<i>A</i> = 0.15 * <i>e</i><i>x</i><i>p</i>( &minus; <i>x</i>).
 
-
 
-
If we could change the albedo from 0.15 to 0.05, the temperature of the Mars would increase by about 6 Celsius degree.
 
==Discussion and Future vision==
==Discussion and Future vision==

Revision as of 10:59, 21 October 2009

Tokyo Tech toplogo.png
Main Team Terraforming Experiments Parts Safety

Contents

Achievement

Melanin production pathway
Quantitative analysis of Darkness

1, We created Blackened E.coli by the melA gene.

Introduction ~Why do we need a Blackened E.coli~

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 the melA gene. The melA gene code for a Tyrosinase (EC 1.14.18.1). 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. Therefore, 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.


Increase Mars temperature

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=Tokyo Tech function T.png .

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.

temperature estimation

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.

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.


Utilize Melanin production pathway

Melanin was made by Tyrosinase (EC 1.14.18.1). 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.

Melanin production pathway

Materials and Methods

Bacterial strains and cultivation

Escherichia coli K-12 JM109 was cultivated in Casein medium during melA expressing analysis. Casein medium used for melA expressing analysis contained, per liter, 1g glucose, 5g NaCl, 0.1g CaCl2, 10g bactotryptone, 15g agar, 5g casein, 0.4mg CuSO4 and 2g l-tyrosine.

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 Casein medium. After 72 hour, we took a picture of these medium and measured darkness of these medium. Darkness was quantified with ImageJ softwere.

Analytical methods

Discussion and Future vision

Conclusion we could build melA into BioBricks, and create blackened E.coli by melanin.

Further blackened E.coli

Please, look under figure. This pathway is very simplified Phe and Tyr biosynthesis pathway. In previous study, forced expression of aroG and TyrA induced large accumulation of Tyrosine in E.coli. So, we will be planning to construct new igem parts to expressing aroG and tyrA.


Control mars temperature by temperature regulated response color change

Finally, we will want to create temperature-regulated genetic circuit using LacI_ts. This protein is temperature-sensitive. It inhibit LacI promoter at conventional temperature. Though, this protein isn’t inhibit promoter when environment temperature reach high.

If this plan is completely execution, E.coli is black to heat the mars during the cold. But, color of E.coli body change for white when the Mars is warmed.

This Genetic Circuit will can controls mars temperature?

References

Retrieved from "http://2009.igem.org/Team:Tokyo_Tech/BlackenedEcoli"