Contribution

We introduced a new way-intestine probiotic-to treat obesity, offering a novel perspective to future iGEM teams when solving the problem of overweight.

1. Experiment

Firstly, we examined the function of the bioengineered product FadL and FadD by adding palmitic acid into standard LB liquid medium with engineered bacteria. The total concentration of the group with both FadL and FadD is significantly lower than the negative control, while the group with only FadL has a lower extracellular concentration, the group with only FadD has a lower intracellular concentration. By doing this experiment, we proved that our system could achieve the palmitic acid intake and metabolization in vitro, and that both FadL and FadD are effective throughout the process. Our conclusion that FadL and FadD are effective in palmitic acid intake and metabolization can be used by future iGEM teams. They can skip the steps of the experiment we’ve done and do experiment based on our conclusion.

Secondly, we also tested the optimum pH and temperature of our engineered bacteria by manipulating these factors and testing the palmitic acid concentration. The results of our experiment can be served as a reference to future iGEM teams. They can either use our optimum pH and temperature to finish experiment in order to save time or compare the optimum pH of our engineered bacteria with other bacteria to conclude the differences.

2. Safety

We designed our kill-switch system, which is composed of L-Rhamnose, Rhamnose promoter PRha, Regulator AraC, Alanine racemase Alr, Terminator, Arabinose promoter PBAD, and RNase Ba, to prevent leakage of probiotics.

We also analyzed the advantages of our design. Firstly, the use of RNase Ba as toxin can reduce the chance for them to influence our enterocytes. Moreover, they have little impact on human, only serving to control the bacteria. Secondly, our engineered bacteria will immediately die if the patients decided not to continue the treatment or when the downstream gene group mutates, thus eliminating potential safety issues.

The components of our kill-switch system can be borrowed by future iGEM teams, so that they can combine the advantages of our components to theirs and eliminate the side effects as much as possible.

3. Team

We shared synthetic biology knowledge with RDFZ SanYa Branch school, in which, we explained our project and goal, introduces numerous biological experiments, and thoroughly explain the subject of synthetic biology through its definition, application, and future. We also educated lower grade students in our school with the harm of obesity. Knowing the safety issues being overweight, these lower grade students can keep fit at an early age and be healthy.

The relationship that we built with students in RDFZ and other iGEM teams can also benefit future RDFZ-CHINA. We are a school iGEM team which has been participating in iGEM for several years, our dedication and contribution can necessarily benefit them in future iGEM competition.