Polycyclic aromatic hydrocarbons (PAHs) are a large group of chemicals. They represent an important concern due to their widespread distribution in the environment, their resistance to biodegradation, their potential to bioaccumulate and their harmful effects.Microbial degradation of PAHs usually targets specific substrates or specific environments. As a result, some PAHS-degrading microorganisms can only play a role in specific types of PAHs. However, once the characteristics of pollutants such as PAHs types and concentrations change, the normal role of microbial flora in the remediation system cannot be guaranteed.

We realized the heterologous expression of degradation enzymes in Escherichia coli through synthetic biological methods, aiming to eliminate this gap, strengthen the adaptability of microorganisms to the environment, and achieve the broad spectrum degradation of PAHs. In our project, laccase CotA from Bacillus subtilis and lignin peroxidase LipH8 from Phanerochaete chrysosporium were overexpressed in E. coli for the remediation of PAHs. To ensure biosafety, we designed a simple and reliable kill-switch.We chose relE toxin from the E.coli RelBE toxin-antitoxin system. Due to the lack of time, we did not have the energy to verify its activity and killing ability, which is the focus of our next experiment.

There are few iGEM teams in Northwestern China so it is inconvenient to ask for help from nearby teams.Moreover, NPU-CHINA is a young team, and we have relatively weak contact with the outside world in terms of experiments. To solve this problem, three teams from Shaanxi built a Northwestern part library in 2019. We used 10 kb DNA synthesis for free provided by iGEM’s sponsors to enrich our part library. This year we continued the tradition, with three schools continuing to build part Libraries and DKU was also drawn in, promising to share future parts. we will continuous to enrich this database in the future, aiming to benefit the teams in northwestern and all over the China.