Background

With a click of finger on the control panel, then a cup of milk with additional Tryptophan in it will get to you in a few seconds. In this way, you are able to release yourselves a little bit from the suffering of anxiety, depression and sleep loss. We surely believe that even small changes can bring you the increment in happiness, and in a long-term they can add up to make you feel brand new. It’s not fantasy or dream but what we are fighting for by our project.

Nowadays, with people attaching unprecedented significance to mental well-being, and with the concept of health extended to mental and behavioral realms, anyone who has the desire of contributing to health causes cannot simply cast the eyes on physical health. We have noticed the discomforting phenomenon that during the COVID-19 epidemic, the rate of insomnia, and its consequences, especially anxiety and depression, has been dramatically ascending in the herd. Thus, we’d like to utilize the technique of synthetic biology to help alleviate the pandemic of mental symptoms, and we have found the ideal candidate, which is tryptophan, an essential amino acid of human being.

However, to make it more easily accepted by our proposed users, it’s necessary that we choose an appropriate conveyor of tryptophan. Since people tend to flinch from supplements with appearances similar to medicines, for instance, capsules or tablets, the milk is chosen for our purpose, as it is daily food to cover a large population and is easy to add tryptophan to. Moreover, as the current situation is that self-quarantine is still frequently required, we ought to consider the accessibility of our product during isolation periods of COVID-19, therefore, a domestic machine is desirable. Eventually, we reached a consensus over the prototype of our final product: a domestic milk maker with the function of production and addition of tryptophan.

Machine

To give a clear introduction, the milk machine we hope to design can be divided into 5 related parts: Temperature control module; Single Chip Microcomputer; Detecting module; Magnetic stirring module; Fermentation module. And throughout the designing process, we fully implement the principles of safety, efficiency and user-friendliness, three things that we consider most in our project.

Safety plays a key role in evaluating whether the machine we design is qualified or not. To secure the safety of our users, we will make some improvements in our module designs if conditions permit. First, to solve the potential risks of contaminative microbes and the purification of our end-product: Tryptophan, we decide to lend a hand from filter biofilm used in industrial production, which is developed well according to the interview with Dr. Liu Ziqiang. On top of that, considering both milk and fermentation broth are liquid, it is essential for us to consider the risk of electrical leakage. As a consequence, we modify our design by adding function of disconnecting plugs when they meet water.

Efficiency is largely influenced by our fermentation module, whether our Tryptophan-producing bacteria can operate the function of toggle-switch with the outside signal. As a result, we construct our Single Chip Microcomputer and Detecting module to make the growing pattern of our engineering bacteria and the outside signals work coherently and smoothly. In this case, our modified E.coli can be able to change its living patterns between growing and producing Tryptophan effectively and automatically, which fulfill the key purposes of our project.

For user-friendliness, we view the project from the view of our proposed customers. The appearance, the volume and the price of our milk machine and so on are all considerations we keep in mind all time, in order to make it more appealing to as large population as we can. The survey we carried out provides us with a new perspective to look at what people actually want to gain with the help of our milk machine. For example, we endeavor to make the machine as portable and small as possible, considering the utility rate of space in our users’ house. All in all,we extremely focus the feedback and needs of our proposed users, because our culmination never is the iGEM but the down to earth application of our project.

Challenges

Ambitious though we were, we did meet with some challenges, both expected and unexpected.

The first challenge came when we began to assemble the prototype. To make the machine function as we expected, it’s necessary to have at least five parts mentioned above, all of which adds to the volume of our product. However, to accommodate to the orientation of a domestic tryptophan producer, our product shouldn’t take up too much space. Hence, to balance the volume and function became our first challenge.

>nother challenge about the prototype is to design a rigorous system of separation so that we can ensure the food safety of our proposed users. According to our researches of factories, the system currently used in the fermentation industry is able to realize carry out this function, however, due to the protection of intellectual property, we could not get access to their design and use them directly. Moreover, this system is way too big for a domestic machine and unfortunately, according to our interview with experts, the technology is not yet mature enough to minimize it. So we are trying to find a way to meet the standard for both size and efficiency

Even after we’ve designed an ideal prototype, the promotion of our product will still be challenging. First of all, some people still have the biased view over biotechniques and microorganisms, hesitating to try our product. Secondly, the market has been filled with tons of so-called sleep-assisting products, such as sleep-assisting pillows, sleep assisting fragrance and so on, some of which have been proved to be useless, limiting the potential of marketing since people might take all of these products as cheating. Last but not least, as mental health is unprecedentedly heatedly discussed these days, it is expected that our product will face a fierce competition that requires absolute advantages to win. We will devote ourselves to make our tryptophan producer more desirable and acceptable by the society, not in iGEM but after iGEM.