Team:Brasil-USP/capa
Degradation of Natural Rubber
Team Brasil-USP
Brasil-USP team's 2015 project is to develop an innovative
and sustainable solution for a significant environmental
problem:
accumulation of
waste tires
Current recycling techniques demand high energy consumption, and are completely overwhelmed by the annual amount of rubber waste. In addition, natural rubber degradation may take up to 1000 years.
We aim to accelerate this process by genetically engineering microorganisms to express and secrete two crucial enzymes for the degradation of natural rubber: RoxA (Rubber oxygenase) and Lcp (Latex clearing protein).
Tires and several other products, however, are composed by vulcanized rubber, which ensures its durability and increase its elasticity and strength. In this regard, for vulcanized rubber degradation, the project may include a pre-treatment, which uses Acidithiobacillus ferrooxidans, bacteria that naturally devulcanizes rubber. Both of these processes will be scaled up in bioreactors.
Both of these processes will be scaled up in bioreactors!
Our Parts
Our team has submitted two different new parts to iGEM registry system: Lcp and RoxA, enzymes involved in natural rubber degradation. Also, we have worked hard characterizing our main DNA circuit. One of the used designs for this was a simple circuit where TetR inhibits GFP production. As our kill switch system is based on TetR inhibition, this experiment provided us key results to better understand and to model it, generating information on the timing balance and promoter strength of our main circuit.
Our main circuit
Our project was designed to combat a serious environmental problem worldwide: the accumulation of rubber products waste. For this end, we designed a simple DNA circuit to be expressed in a model bacteria, E.coli. The designed DNA circuit will co-express two essential enzymes for rubber degradation, Lcp and RoxA, followed by their exportation – guaranteeing maximum contact with the threated materials. Both of these enzymes interact with the polymers composing natural rubber, generating several products. Between these, the most abundant is ODTD, a triisoprene unit that can be transformed into a high value fuel. Therefore, our project doesn’t only removes rubber waste from the environment, but it also turns it into a product with high aggregate value.
Entrepreneurship
Given the high potential for an industrial application, we have investigated possible business plans that could turn our project into a competitive startup. As a first step, we have met with warehouses where waste tires are treated and discarded to both promote our ideas and learn more on how to implement our system into their reality. Several chemical processes involved in our project are indeed complex, demanding some extra sfatety care.
And this is Brasil-USP Team, from University of São Paulo!