Introduction to the project

Energy depletion of the earth has been a critical problem. We must fine another fuels to replace petroleum. The most common biomass fuel is ethanol. But ethanol still can not be substituted completely for petroleum, because of its causticity to the metal of engine. If we want to generate energy with ethanol only, we may have to change whole engine to be in different material. That’s very inconvenient. Unlike ethanol, isobutanol can be used on car engine safely. In fact, isobutanol has been used in many purposes. Here comes a lot of applications and advantages of isobutanol. For example, organic solvent, reactant of organic mechanism, antifreeze and so on. One of the advantages is that its high ratio of the heat of combustion is very close to petroleum. It means that isobutanol is suitable to be fuels. So we finally choose it to be our project. What’s more, if we can generate energy from cellulose by converting it into glucose or even isobutanol, it will be more helpful to people’s life. We believed that isobutanol must have wide development in the future. However, according to many research, we found that the E.coli used for producing isobutanol always died for the rising concentration of isobutanol, so the yield always couldn’t get higher. Fortunately, we figured out two innovative and brilliant solutions to solve this serious problem. We will introduce our idea on our wiki in detail.

　Project details

　Enzyme for isobutanol

(developing)

　Temperature control system

The low temperature release system is a way to let e.coli produce isobutanol efficiently . Because isobutanol and isobutyaldehyde are toxic to the e.coli , the system avoid e.coli facing them at the beginning . The following picture is our system.

At the beginning , we will let E.coli stay in 37°C environment. After having enough 2-Ketoisovalerate , we will move E.coli into 30°C environment for producing the final product , isobutanol. It can make us get isobutanol successfully and efficiently.

This is our biobrick. The most important part of our biobrick is 37°C ribosome binding site gene. We separate our biobrick into two parts . The first part is which has 37℃ ribosome binding site gene and the second part is under the first one.

And now we're introducing how our system works.

When being in 37°C environment, the first part will be translated and produce tetR protein to inhibit Ptet promoter. The second part will not be translated. Then we can produce intermediate , 2-Ketoisovalerate.

After getting enough 2-Ketoisovalerate , E.coli will stay in 30°C environment. The ribosome will not bind the 37°C ribosome binding site and tetR genes will not be translated. Then the second part will be translated successfully. At the end , we can get the isobutanol.

　Result

The report shows that we use fluorescene protein to mark the second part of our biobrick . We can see that fluorescene protein staying in 30°C environment will have higher expression than staying in 37°C environment . According to it , we can see that our system do truly work!

　Zinc finger

(developing)

　Result

(developing)

　Instrument

(developing)

　Conclusion

(developing)

　Optimization

(developing)

　Future works

(developing)