Http://2013.igem.org/Team:KU Leuven/Project/Glucosemodel/EBF

In this part, we will present you the insight of the E-β-farnesene (aka EBF) project. EBF is the most universal alarm pheromone that is released by almost all the 4000 aphid species in response to predation or other disturbance, and the beneficial consequence among aphids due to EBF is presumed to be allowing the population taking evasive action after perception of EBF, therefore the successful survival rate will be increased. In addition to the short term repelling effect, EBF can also cause the change in aphid’s development, fecundity, survival when introduced to different growth stages of aphid in a long term. Moreover, the natural predators of aphid such as ladybug can recognize EBF as well; this will lead to the attraction of ladybug.
Hence, we chose EBF as a major part in our design to perform the act of repelling the aphids away. In the following sections, we will bring you on a tour of the general background, the model and the genes, the wetlab work, and the biobricks we built.

Herein, we incorporated EBF synthase into the metabolic pathway of E.coli, with which, (2E,6E)-farnesyl diphosphate will be converted into (E)-beta-farnesene (EBF) and diphosphate as depicted in the reaction below.
The enzyme’s activity will be achieved the maximum with the present of Mg²⁺ with the concentration of 5mM. The ideal pH for EBF synthase will fall in the range of 5.5-7. For the Artemisia annua protein the K_M is 0.0021mM, Kcat/K_M=4.5, turnover number 0.0095s^-1. For the Streptomyces coelicolor protein the K_M is 0.0168 and the turnover number 0.019s^-1.