In order to realize the application of PLA and 2PE which are produced by the engineered bacteria in daily life, we have designed two kinds of garbage can lids and emulsion. According to our project. we will give a detailed account of the principles and functions of our application design.

Garbage can lid

    In order to eliminate foul smell produced from special bacteria in our daily life, we designed a special garbage can lid that has already been made through 3D printing technology. This garbage can lid is used to load the engineered bacteria that are able to produce PLA and 2PE, which is suitable for use in waste containers of laboratory.
To ensure biosafety, we introduced light-regulated suicide systems into the engineered E. coli in this section. In addition, in order not to affect growth of the engineering bacteria, we chose dark materials to make our garbage can lid, so that the engineered bacteria would not be destroyed under normal circumstances. And only when the bacteria leaked to the external environment, the suicide system would be turned on, and expression of the mazf would crack the bacteria's mRNA and kill it effectively.

    The whole lid consists of three parts. The top is a cover that can be opened, which makes it easy to add bacteria at any time. And the middle portion is a cylindrical liquid reservoir which is used to load engineered bacteria. The bottom of the lid is a circular leaky mesh with holes and transverse grooves evenly distributed on it, which enables the products expressed by bacteria to enter the can evenly and save the amounts of products. The bottom of the lid has an axis connecting the red button at the top. When we press the button, the bacteria in the middle of the lid will flow down the hole at the bottom into the trash can to achieve the purpose of inhibiting harmful bacteria in the trash can and producing rose fragrance.

Lotion

    We designed an lotion to eliminate the bromhidrosis. In order to solve the problem of armpit odor, we have designed an emulsion by using our project. This emulsion works by using engineered bacteria to produce PLA and 2PE to prevent armpit odor. As we have introduced, PLA can inhibit the growth of Corynebacterium and Staphylococcus epidermidis which are the main resource causing armpit odor. Meanwhile, 2PE can bring us a pleasant feeling by gives off rose fragrance. To make this emulsion a reality, we turned engineered bacteria capable of producing PLA and 2Pe into lyophilized powder and added it to the emulsion containing nutrients necessary for bacterial growth. When we use this product, we can directly apply the emulsion to the underarm. The emulsion not only provides nutrition for the engineered bacteria, but also can effectively fix them on the skin, so that the engineered bacteria can work continuously underarm.
    The accessory product of the lotion is an emulsion containing arabinose. When the user does not want the bacteria to produce PLA and 2-PE, apply it, the arabinose can open the suicide system and express mazF.
    Compared with the body lotion and deodorant on the market, this product is more environmentally friendly, more effective, longer in action and cheaper.

Future

    We hope that our products to be more widely used and effective. In the future work, we will continue to improve our product design, including their functions, practicality, appearance and other aspects. In addition, we try to apply them to more complex environments, such as household waste, kitchen waste and so on.